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II. Grassland Habitats in California

National Grassland Trends

Across North America, grasslands cover 358 million acres (145 million hectares), the majority of which are privately owned, and are important habitat for grassland bird species (North American Bird Conservation Initiative 2013). Public grasslands make up around 13% of the total acreage in North America although less than 2% is managed solely for conservation values (North American Bird Conservation Initiative 2011). Public grasslands are largely subject to multiple use demands such as livestock grazing, energy development, and public recreation, yet there are opportunities to manage these areas with an awareness of grassland bird habitat enhancement and conservation (North American Bird Conservation Initiative 2011).

Grassland birds are well known to be experiencing significant population declines throughout North America (Knopf 1994, Brennan and Kuvlesky 2005, Sauer and Link 2011). In the most recent analysis of the North American Breeding Bird Survey (BBS), Sauer and Link (2011) report that over the last forty years, grassland-obligate bird species across the continent experienced a 37% total population decline. There are many suspected reasons for this decline including the regeneration of eastern forests, fragmentation and subsequent degradation of midwestern prairies and the deterioration of western rangelands by a combination of exotic plant and conifer invasions, drought, lack of fire, improperly managed livestock grazing, and energy development (Knopf 1994 , Brennan and Kuvlesky 2005, Naugle 2011).

Conservation practices that create partnerships between private landowners and public agencies through various Farm Bill programs to enhance grassland bird habitat are increasing the abundance of grassland dependent species. Native grassland restoration projects on public land have also brought back bird species to potential grassland breeding habitat where they were previously absent (North American Bird Conservation Initiative 2011 and 2013). Let’s see what we can do in California.

California Grasslands

Grasslands in California are currently estimated to cover almost 11 million acres or 4.5 million hectares (Jantz et al. 2007) which is approximately 11% of the state’s wildland vegetation. With a prediction of adding 9.3 million people to the state over the next decade, the 2010 FRAP (Forest and Resource Assessment Project) report highlights the need for conservation of private and public rangelands. Annual grassland in California is currently considered the most at risk habitat type for conversion (to urban development and/or intensive agriculture) and fragmentation; the highest risk areas are the south coast, bay/delta and Sierra bioregions (FRAP 2010). More than 80% of these California grasslands are privately owned and only 4% designated as preserved grassland.

The primary geographic scope of this bird conservation plan addresses two of the most common grassland vegetation types throughout California, which are generally recognized as ‘Valley Grassland’ and ‘Coastal Prairie’. These two broadly defined grassland types can be subdivided into finer scale classification units such as alliances and associations, which are based on plant species composition (Sawyer et al. 2009). However, focusing on the large scale vegetation definitions of valley grassland and coastal prairie is appropriate for the purpose of this plan (for detailed descriptions of grassland alliances and associations in California, see Sawyer et al. 2009 Manual of California Vegetation). Valley Grassland is found in the low elevation foothills around the Central Valley ranging up to 4,000 ft, specifically the foothills along the west side of the Sierra Nevada range. The central and southern Coast Ranges have Valley Grassland, as well as parts of the Transverse and Peninsular Ranges (Bartolome et al. 2007). Valley Grassland, also known as South Coastal Grassland, and Coastal Prairie meet and intergrade on coastal terraces in central California. The Coastal Prairie grassland type ranges along the coast from the border with Oregon, extending several miles from the coast and south to San Luis Obispo (Ford and Hayes 2007).

Valley Grassland makes up the majority of all grassland habitat in California. Although it is dominated by nonnative annual grass species especially in the lower elevation areas, Valley Grassland can also be quite spatially and temporally diverse. In certain rainfall years, Valley Grassland native wildflower displays appear within patches of exotic annual grasses. Throughout its range Valley Grassland includes stands of purple needlegrass (Stipa pulchra), a native bunchgrass, especially appearing on south-facing slopes where it intergrades with coastal prairie (Bartolome et al. 2007). Historical references suggest that pre-invasion (pre-European) valley grassland vegetation, especially in dry areas in the south or away from the coast, was likely all native annual plants (forbs and grasses) and not perennial grasses (D’Antonio et al. 2007, Schiffman 2007).

Coastal Prairie vegetation is more often dominated by native grasses and forbs than Valley Grassland. Perennial bunchgrasses California oat grass (Danthonia californica) and tufted hairgrass (Deschampsia caespitosa) along with a relatively high diversity and abundance of native forbs or wildflowers make up the species composition of Coastal Prairie (Ford and Hayes 2007). Compared to Valley Grassland, Coastal Prairie occurs in a much more mesic (wetter) region within California, has a higher abundance or cover of native vegetation, and typically exists in a matrix of grassland, shrubland and oak woodland. Without periodic disturbances like livestock grazing or fire, Coastal Prairie can become invaded by woody vegetation, including native and nonnative trees and shrubs (Ford and Hayes 2007).

Factors driving grassland diversity within California include variation in soil and topography, spatial and temporal variability in rainfall amount and timing, and at the more local scale, land management history. Unique soil types such as serpentine, that have patchy distribution throughout the state, are often hotspots of native grassland diversity, and in the case of serpentine, host a high proportion of endemic plant species (Harrison and Viers 2007). California’s variable climate, characterized by a Mediterranean style wet winter and dry summer as well as a spatial rainfall gradient from north to south and coast to interior, is another reason for the high native diversity of grassland species composition. Average annual rainfall amount can range from as little as 5 inches for valley grassland in the San Joaquin Valley to a north coast extreme of 40 inches in coastal prairie (Minnich 2007).

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III. Conservation Planning Process

To facilitate the use of birds to guide conservation planning efforts, California PIF draws on the concept of bird focal species. Because birds occupy a wide diversity of ecological niches in grassland habitat, they serve as useful tools in the design of conservation efforts. The habitat requirements of the full suite of focal species should embody all the habitat characteristics, attributes, and management regimes representative of a healthy grassland system (Chase and Geupel 2005; Alexander et al. 2007, Young et al. 2015, Geupel et al. 2016). For example, the species with the most demanding or exacting requirements for an ecological characteristic, such as patch size or average grass height, determines its minimum acceptable value. Therefore, the assumption is that a landscape designed and managed to meet the focal species’ needs encompasses the requirements of other species (Lambeck 1997). Additionally, certain focal species should serve as meaningful indicators, and thus should have populations and distributions large enough to be easily monitored and to provide sufficient sample sizes for statistical analysis across sites and over time.

Selection of Grassland Focal Species

More than 60 bird species make significant use of California's grasslands during some portion of the year. In order to focus our efforts, the authors along with input from attendees at the first stakeholder meeting, chose to create a shorter list of birds and needed some basis for prioritizing among all the potential species. We recognize that any list of focal species for any habitat will be subject to criticism. There will be species omitted that others think deserve inclusion and species included that some will argue could be left off the list. Through an inclusive PIF process with experts in California, we attempted to compile a list that would allow us to examine the full breadth of issues affecting grassland birds in California. For convenience, we decided that a workable list of focal species should be less than 25. We wanted a list of focal species representing birds that use grassland as their primary habitat either in the breeding season or in winter, are of some conservation concern either at the state or continental level, are relatively easy to monitor for responses to habitat changes and management practices, and represent the full spectrum of grassland types within the geographic scope of the plan. In order to proceed in a logical fashion, we created a set of criteria, posed as questions, which we used to rank all grassland-using species (see below).

As a first step, we simply looked at each grassland-using species (Appendix A) and ranked the species based on how many times the answer to the question posed was "yes" for a given season (breeding or winter). Then we ranked them based on the combined total for both breeding and winter seasons. Using these criteria, we produced a list of 21 focal species (Table 1). We then shared this list with other experts and examined the list to ensure that we had species representing all the important subsets of grassland within our area of concern. Based on this, we chose to add two additional species to the list: Mallard and Swainson's Hawk. We added Mallard because they make use of a particular type of grassland structure (fallow, ungrazed grassland near water) for nesting not necessarily well represented by other species on the list. Swainson's Hawk was added because of its status as a state-threatened species and because, while it may currently rely more on cropland than grassland for foraging, its historical use of grassland was certainly important in the state.

Many bird species that rely on the grassland habitat for some portion of their lifecycle are associated with other habitat types as well. Indeed, California’s grasslands often occur on the landscape mixed with or adjacent to the other habitat types addressed in the other California PIF bird conservation plans. Thus, several of the grassland focal species we selected for this plan (Table X) were also selected as focal species in other California PIF bird conservation plans. For example, Yellow-billed Magpie is both a grassland and oak woodland focal species, and Tricolored Blackbird is both a grassland and riparian focal species.

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Focal Species Population Trends

An analysis of Breeding Bird Survey (1966-2011) and the Christmas Bird Count (1981-2012) suggests that both breeding and wintering populations of many grassland focal species are experiencing significant long-term population declines within California (Table 2). Loggerhead Shrike appears to have the steepest per year population decline in California from both BBS and CBC surveys; statistically significant trend annual effect sizes for breeding populations are -2.8% and wintering populations are -3.9%. Seven of the focal species had statistically significant declines from both breeding (BBS) and wintering (CBC) surveys; these were Killdeer, American Kestrel, Loggerhead Shrike, Yellow-billed Magpie, Horned Lark, Lark Sparrow, and Western Meadowlark. Wintering populations of Northern Harrier, Tricolored Blackbird, and American Pipit appeared to decline significantly, however there were no significant trends in the BBS data. And although the BBS data suggests a positive population increase in Tricolored Blackbirds (albeit not statistically significant), coordinated statewide surveys targeting breeding colonies of Tricolored Blackbirds indicate that the species has experienced a drastic decline in recent years (Tricolored Blackbird Portal; see species account), declines which prompted an emergency state-listing of the species in 2014 (the emergency listing expired in June of 2015, but the species’ status is currently under review for protection under the Federal Endangered Species Act; see species accounts).

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IV. Management Issues Affecting Grassland Birds in California

Grassland Habitat Loss, Fragmentation, and Degradation

The most important threat to California’s grassland birds is habitat loss, fragmentation and degradation caused primarily by the conversion of working ranches, or rangelands, to housing developments and intensive agriculture (Shuford and Gardali 2008). California’s ranching industry has been in decline due to economic pressures, such as rising costs and shrinking profit margins, and loss of ranch infrastructure as rangelands are converted to other land uses (FRAP 2010). It is estimated that 47,000 acres of rangeland per year are permanently changed to new land-use types. Rangelands surrounding the Central Valley have the highest levels of grassland habitat loss and fragmentation for the state (FRAP 2010). In a recent study conducted by the Nature Conservancy, more than 480,000 acres of rangelands in and around the Central Valley were converted to urban development (49%) and intensive agriculture (40%) over a 24 year period from 1984 – 2008 (Cameron et al. 2014). Given this rapid rate of habitat loss, protecting California’s rangelands should be a high priority for conserving the state’s diverse suite of grassland plant and wildlife species.

Conversion of grasslands to orchards or row crops is a large portion of the land-use change in the Central Valley of California. This agricultural intensification creates a permanent change in the grassland ecology of the area (Stromberg and Griffin 1996) which policy protections like the Williamson Act do not protect against (more about the Williamson Act below). Almond orchards in particular have increased in economic importance around the Central Valley as part of the diversification of ranch holdings. However, some ranchers are now complaining that their rangelands are being surrounded by new orchard developments, in part because the water demand from almond orchards on local aquifers can cause wells or stock ponds to dry up, especially in drought years (Wozniacka 2013). Pesticide use from orchards and crops like alfalfa that are adjacent to grassland habitat can both directly kill bird species and cause indirect effects like reductions in prey. When comparing the effects of lethal pesticide use and intensive agriculture across North America, pesticide acute toxicity appeared to be a better predictor of the decline of grassland and farmland bird species (Mineau and Whiteside 2013).

With the high rate of grassland habitat loss in California, one obvious consequence is the fragmentation of remaining grassland areas. With the increasing urbanization of the central and southern coastal regions of the state, the agricultural areas and rangelands are transforming into larger metropolitan areas in a patchwork of grassland, ranchland, parkland, other types of agriculture and both urban fringe and exurban residential developments (Theobald 2005, FRAP 2010). Habitat fragmentation and the loss of large contiguous grassland areas could be driving grassland bird decline in California. However, very little California-specific research exists on the effect of habitat fragmentation on grassland birds. References to studies conducted outside of California but within grassland habitat in western and mid-western North America are included in this discussion.

Fragmentation of grasslands can cause the degradation of the remaining habitat by multiple problems including shrinking grassland areas or patches, predation by feral cats and other predators common around urban areas (raccoons, skunks, rats, etc.), and increasing exotic plant invasion. Large contiguous areas of grassland are known to be important for many grassland-obligate species (e.g. Herkert 1994, Johnson and Igl 2001). Ribic et al. (2009), in an overview of multiple studies throughout North America, found common grassland species to increase in density or occurrence with larger intact patches of grassland. Grassland bird species have also shown sensitivity to grassland edge effects which can be more prevalent in highly fragmented habitat (Renfrew and Ribic 2003, Patten et al. 2006).

One indirect effect of habitat fragmentation is the increased rate of nest predation and lower reproductive success in smaller and isolated grassland areas. Meso-predator release has been hypothesized as one of the causes of this decreased reproductive rate (Soulé et al. 1988, Crooks and Soulé 1999), where the decline of top mammalian carnivores like coyotes in highly fragmented areas allows an increase in smaller nest predators like feral cats or other suburban subsidized carnivores like raccoons or rats. This may be an important grassland bird population impact in the highly urbanized and fragmented landscape of California. Bird predation by feral cat populations, a problem in suburban areas, (Loss et al. 2013) has been shown to have a larger impact on local bird populations than pets. Grassland habitat within an urban or exurban framework also has a higher level of disturbance to breeding birds by both hikers and dog walkers (Maestas et al. 2003, Banks and Bryant 2007) Development proximity to grasslands can cause higher levels of invasion by nonnative weeds (Hansen et al. 2005) which can change the structure and function of the grassland. More research is needed to determine the effects of grassland fragmentation and degradation on California grassland bird species.

Grassland Structure, Disturbance, and Native vs. Non-native Plants

Vegetation structure is well known to be a primary factor for grassland birds when they choose areas for nesting and foraging. California grassland with scattered native bunchgrasses and forbs probably creates a preferable structure to the habitat that includes variation in the height and density of grasses and patches of bare ground. A study in central California found that Horned Larks and Western Meadowlarks were more likely to be found in Valley Grassland with some level of native plant cover. Native plant abundance in this study ranged from zero to 40% and consisted of primarily the native bunchgrass purple needlegrass (Gennet et al. 2017). Another study in California that compared native and exotic dominated grasslands (Goerrissen 2005), found that Grasshopper Sparrows were also more strongly associated with native grasslands that had similar levels of exotic plant cover. In northeastern Oregon, Kennedy et al. (2009) found the same grassland bird behavior in a more arid bunchgrass prairie community with low to moderate levels of exotic plants. In this study, Kennedy et al. (2009) found there was no association between the level of nonnative cover and reproductive success metrics like nest density and productivity for several grassland bird species, including Horned Larks, Western Meadowlarks and Savannah Sparrows.

Moderate intensity livestock grazing can also create a patchy grassland structure (Fuhlendorf et al. 2006, Derner et al. 2009), potentially in habitat like valley grassland that has lower native content and often a dense even layer of exotic annual grasses (Gennet et al. 2017). Gennet et al. (2017) found Horned Larks prefer livestock grazed grassland, although the association was less strong in areas with higher native plant cover.

A study in southeastern Arizona suggests insect prey abundance may be another reason grassland birds prefer areas with a mix of native and exotic plants (Litt and Steidl 2010). Litt and Steidl (2010) found increasing levels of exotic plant invasion have a strong negative effect on insect richness and overall abundance. Grassland bird species are known to primarily eat insects during the breeding season (Wiens and Rotenberry 1979) which probably explains a higher presence in native grassland areas in California. However, when the Kennedy et al. (2009) study compared levels of nonnative plant cover there was no noticeable difference in insect abundance. In this arid bunchgrass area, Kennedy et al. (2009) suggest the greater impact of an increase in nonnative plants was the decrease in bare ground and the loss of easy foraging indicated by a diet switch away from ground dwelling insects.

A few studies from California have suggested that the native fraction in grasslands (i.e. cover of native perennial grassland species) is an important habitat feature for grassland birds (Gennet et al. 2017, Goerrissen 2005). However, more research is needed to determine if there is an optimal or threshold cover of native grasses to provide suitable bird habitat. Regardless, it seems that grasslands with a high percentage of native species should be prioritized for conservation.

Invasive Plants

Invasive plant or weed management is an important part of grassland stewardship in California. Grassland birds are impacted by invasive plants from multiple pathways such as changes in habitat structure or a decrease in food resources. Grassland communities are impacted when shrubs and trees invade grassland areas, especially along the northern coast. Nonnative annual grasses and forbs dominate large patches of California’s grassland and can form an unbroken dense or homogenous layer of vegetation that is not necessarily suitable wildlife habitat. Invasive plants in California’s natural areas are plants that have a negative impact, grow unassisted, and spread away from where initially located. Nonnative or exotic plants are plants considered to be originally from outside of California but may or may not be invasive. Naturalized plants are nonnative plants that persist without human intervention in wildland areas, but are not necessarily considered invasive (UC IPM 2014).

Woody plant invasion (and eventual vegetation type conversion to shrubland or woodland) is a common grassland management concern across North America. Grasslands in California are part of a dynamic matrix of grassland, shrubland and woodland especially along the coast. Northern coastal scrub often intergrades with coastal prairie grasslands as native shrubs like coyote brush (Baccharis pilularis) invade the grassland when disturbance such as fire or livestock grazing are removed (Ford and Hayes 2007). Douglas fir (Pseudotsuga douglasii) and pine seedlings are also known to invade without disturbance along the northern coastal grasslands. Nonnative European gorse (Ulex europaeus) and broom (Genista and Cytisus spp.) invade grasslands along the coast and farther into the Coast Range. As the structure of the grassland changes to a shrub or woodland, the grassland bird community is lost.

Today’s California grassland mix of native and naturalized exotic plants provides the majority of grassland bird habitat in the state. Naturalized exotic annual grasses and forbs, largely from the Mediterranean region and thus well adapted to the climate, dominate most of California’s grasslands. The conversion to significant areas of exotic annual grassland happened before the mid-1800s in California (Schiffman 2007) and persists in large patches throughout both valley and coastal prairie grasslands. The current mix of native and naturalized exotic plants in California is likely not cost-effective nor feasible to shift to an entirely native grassland and, with appropriate management, still provides suitable habitat for grassland birds. Common Valley Grassland invasive plants:

Invasive annual herbaceous plants like yellow starthistle, medusahead and goat grass are of management concern in interior Valley Grassland areas and are rated High concern in the CalIPC Invasive Plant Inventory Database (http://www.cal-ipc.org). These species are unpalatable and somewhat toxic to livestock. General management recommendations for these important invasive weeds include two to three years of site-specific strategic management, utilizing a combination of targeted control techniques like mowing, herbicide, prescribed burns and livestock grazing. Ongoing efforts of monitoring and treatment are needed to maintain control especially of larger infestations.

• Yellow starthistle (Centaurea solstitialis) is one of the most invasive and widespread weeds in California, where it infests over 14 million acres of rangeland and grassland. This weed is a major consumer of groundwater, can reduce access to recreational areas, reduces livestock forage quality and yield, degrades wildlife habitat, and decreases native plant and animal diversity. There are many sources of information on the life cycle and management of this pest including the online Yellow Starthistle Management Guide (DiTomaso et al. 2006).

• Medusahead (Taeniatherum caput-medusae) is an annual invasive grass that is estimated to occupy more than a million acres of rangeland and grassland in California. The high silica content of medusahead discourages livestock grazing when mature and slows its breakdown creating a persistent layer of thatch. Without disturbance, medusahead thatch suppresses the germination, establishment and survival of other plant species often creating a monoculture. There are many sources of information on the life cycle and management of this pest including the online Medusahead Management Guide for the Western States (Kyser et al. 2014).

• Goatgrass (Aegilops triuncialis) is an annual invasive grass that is expanding in its range throughout California and Oregon and infests many grassland types including serpentine. Goatgrass has persistent thatch accumulation because of high silica content which can suppress other plant species. Goatgrass density appears to increase with both season-long heavy livestock grazing and periodic high intensity/short duration grazing. Strategically timed burning in combination with herbicide appears to have the best results (DiTomaso et al. 2013b). There are many sources of information on the life cycle and management of this pest including the online UC ANR publication Barb Goatgrass (Davy et al. 2008)

Common Coastal Prairie invasive plants:

Coastal Prairie grasslands have less studies and publications regarding invasive plant management and typically a more native plant community than Valley Grassland. Within Coastal Prairie grasslands in northern California, two of the more widespread invasive plants are perennial grasses like velvet grass and sweet vernalgrass. General management recommendations for these important invasive weeds include site-specific strategic management plans, utilizing a combination of targeted control techniques like mowing, herbicide, prescribed burns and livestock grazing. Ongoing efforts of monitoring and treatment are needed to maintain control especially of larger infestations.

• Velvet grass (Holcus lanatus) is a perennial considered moderately invasive by CalIPC in Coastal Prairie grasslands and wetlands. Velvet grass out competes the native plant community, especially where populations are dense, and quickly colonizes disturbed areas. Intensive grazing and burning are known to reduce the amount of velvet grass, however, light grazing and occasional mowing or burning can cause the grass to increase (DiTomaso et al. 2013b). Tule elk greatly reduced the cover of velvet grass in a study looking at the effect of native grazing animals on the plant community in Coastal Prairie grassland within Pt. Reyes National Seashore (Johnson and Cushman 2007).

• Sweet vernalgrass (Anthoxanthum oderatum) is a perennial invasive grass that occurs throughout Coastal Prairie grasslands in California as well as grasslands in the foothills of the Sierra Nevada. It is considered a poor forage grass for livestock and ranked as moderately invasive by CalIPC. More research is needed to allow for management recommendations on the control and reduction of sweet vernalgrass. Attempts to reduce the abundance of the perennial grass with livestock grazing and burning have had poor results (DiTomaso et al. 2013b).

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Energy development

Wind, solar, agrofuel, fossil fuel, and geothermal energy developments have varying degrees of effect on California grassland habitat and wildlife. Geothermal systems have the smallest energy development footprint and are not typically located in grassland areas within the state. Most California-specific studies looking at the direct and indirect effects of energy development on grassland birds have focused on wind power (Naugle 2011).

Placement of new energy developments, especially wind and solar power plants which require large areas per unit of power, should be in locations that are already experiencing heavy disturbance by people or already degraded wildlife habitat (i.e. locate energy systems adjacent to urban areas, in grasslands with a history of intensive agriculture or already low native plant diversity) (Leddy et al. 1999, Copeland et al. 2011). As the push for renewable energy sources drives the development of wind and solar energy systems into more and more places in California, care should be taken to include plans for grassland bird habitat protection.

Wind: Wind farms became part of the power landscape in California in the 1980s and its installed capacity in 2009 was second only to Texas (Johnson and Stephens 2011). About 95% of the state’s wind power is currently generated in central and southern California: Altamont Pass Wind Resource Area, Tehachapi Ranges and San Gorgonio Pass (California Energy Commission 2014a).

Most information about the direct effect of collision-related mortality from wind energy in California comes from the Altamont Pass Wind Resource Area (APWRA), a hilly area approximately 45 miles east of San Francisco dominated by extensive valley grassland habitat. Mortality estimates at APWRA, an area with some of the oldest generation wind turbines, that detailed the high rates of likely turbine collision related deaths for multiple bird species (Orloff and Flannery 1992) prompted efforts to observe and model bird behavior in this area (Smallwood et al. 2009a, 2009c). The APWRA has a much higher raptor fatality rate (1.5-2.2 raptor fatalities per megawatt per year) than the other two wind power areas in California and the highest rate in western North America (Johnson and Stephens 2011). Many of the focal grassland species in this plan are affected by wind turbine collisions in this area, however, Golden Eagles (Aquila chrysaetos) and Burrowing Owls (Athene cunicularia) appear to have the highest death rates (Smallwood and Karas 2009, Smallwood et al. 2010). Locating turbines out of high mortality-rate areas as well as changing to new generation turbines, that are taller and potentially cause less wildlife collisions, could significantly reduce avian fatalities. However, more research is needed and there may be consequences for other wildlife species especially bats (Smallwood et al. 2009b, Johnson and Stephens 2011).

Direct loss of habitat from wind infrastructure such as roads and turbines is less than other energy developments, however, most studies outside of California showed behavioral avoidance of these structures by sensitive grassland bird species which could potentially have a larger scale impact (Kuvlesky et al. 2007, Pruett et al. 2009, Bayne and Dale 2011). Wind energy development may also have indirect impacts to birds and other wildlife through habitat fragmentation, promoting invasive plant establishment, and habitat use avoidance of wildlife. However, few studies have investigated these indirect effects, and no published studies specifically from California. California-specific studies are needed to inform wildlife guidelines for the current build-out of wind energy in the state’s grassland and desert areas.

Guidelines for wind energy and birds from (California Energy Commission): http://www.energy.ca.gov/windguidelines/index.html (accessed February 2014)

Guidelines for range management practices to reduce wind turbine impacts (California Energy Commission): http://www.energy.ca.gov/2008publications/CEC-500-2008-080/CEC-500-2008-080.PDF (accessed February 2014) These guidelines came out of an experimental study (Smallwood et al. 2009b) that manipulated vegetation growth through sheep grazing around the wind turbines. Results were inconclusive, however, because areas under the turbines left ungrazed did not have significantly higher vegetation than the grazed areas due to a heavy rain year followed by an extremely dry year (2006-2007).

Solar: Impacts of solar development on grassland birds are currently not well documented in California, however, there is a recent increase in the approval and construction of both photo-voltaic arrays and thermal technology plants in the state. 87% of the U.S. installed large (utility-scale) solar power plants are in California (Copeland et al. 2011) although most are in desert rather than grassland areas (California Energy Commission 2014b). The recently built California Valley Solar Ranch (San Luis Obispo County) is on grasslands in the southern Coast Range near the Carrizo Plain National Monument. Mitigation for the solar plant involves the purchase of adjacent land set aside for wildlife protection with conservation easements (Wang 2013).

Agrofuels: Agrofuels are a type of biofuel that is produced from agricultural crops, like corn or switchgrass (Panicum virgatum), which are converted to energy by some process. Proponents of switchgrass, a warm season perennial bunchgrass native to grasslands across North America (except the coastal western states CA, OR, and WA), are studying the ability of growing this agricultural crop to create grassland bird habitat while also producing fuel from the harvested plant’s biomass (Robertson et al. 2012). This type of agrofuel from perennial grasses has more potential to be good bird habitat than corn/ethanol production although the agricultural trend is toward monocultural stands of switchgrass that are not managed specifically for wildlife habitat(Roth et al. 2005, Robertson et al. 2011). Recommended switchgrass management for grassland bird habitat would include reducing chemical use, maximizing both structural and plant species community heterogeneity within fields, and harvesting biomass after the breeding season (Fletcher et al. 2010).

In California, there is a potential issue with the invasive nature of nonnative switchgrass (Fletcher et al. 2010) especially in wetland or riparian systems. DiTomaso et al. (2013), however, have completed the recommended invasive risk analysis and field evaluations for switchgrass and conclude that dryland regions of the state show little risk even with widescale production. The phenological timing of switchgrass, late germination at the end of spring, makes it an intensive irrigation crop for cultivation in California. Site specific studies in the state are needed to determine the possibilities of considering switchgrass crops as potential grassland bird habitat.

Fossil fuels: Fossil fuel energy developments in California are essentially oil and natural gas energy systems. Oil and gas leases in California run throughout the state but 2012 production is concentrated in these southern counties: Fresno, Kern, Los Angeles, Monterey, Orange and Santa Barbara (California Department of Conservation 2014). Few published studies from North America, and none in California, look at the effects of fossil fuel development on grassland birds but the intensive development and infrastructure of an oil field causes a direct loss of habitat, habitat fragmentation, and degradation of the surrounding area. The highest North American concentration of currently (2009) producing oil and gas leases are in Canada and the mid-west (Copeland et al. 2011).

Climate Change

In a recent assessment, Gardali et al. (2012) found that at-risk grassland (and oak woodland) birds were the least vulnerable taxa to climate change. This opinion is largely based on the prediction that grassland vegetation will expand within California, rather than contract as predicted for many other habitat types (Lenihan et al. 2008). However, the native or nonnative quality of the future grassland is not included in these predictions. Thus it is possible that although there may be more grassland habitat in the future, it may be of poorer quality. Sandel and Dangremond (2012) predict that invasive annual grasses may dominate native remnant patches by 2030 because their larger leaf trait is more amenable to the prediction of more summer rain. When climate change factors are modeled in comparison with the impact of urban development in California, however, more bird species, including Western Meadowlarks and Savannah Sparrows, are projected to decline from future development than climate (Jongsomjit et al. 2013).

Future climate scenarios include an increased likelihood of longer, more extreme drought periods, which would undoubtedly impact grasslands, wetlands, and other wildlife (NABCI 2010). Reduction in available wetland habitat would impact a subset of grassland bird species that also depend on wetlands for part of their life histories (e.g.Tri-colored blackbird and Mallard).

Though beyond the scope of this plan, bird species that utilize alpine grasslands, such as breeding American Pipits, will likely be more effected by climate change (Verbeek and Hendricks 2012) as the projections of change are more extreme at higher elevations and more northern latitudes.

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V. Grassland Sites of Importance in California

Grasslands considered to be important for focal species in this plan are summarized here as a first attempt at highlighting areas for conservation within the state. We used a combination of location data on grasslands in California and Audubon’s Important Bird Areas (IBA) program to provide a first cut at what are the most important areas for targeted grassland bird conservation.

California grasslands were identified using a spatial data layer from the USDA Forest Service existing vegetation (eveg) mapping effort; part of the Classification and Assessment with LANDSAT of Visible Ecological Groupings (CALVEG) mapping product at a scale of 1:24,000 to 1:100,000 using imagery from 1997 to 2010 to classify vegetation types. We overlaid the grassland eveg layer with IBA boundaries in California to calculate the amount of grassland within each IBA. Audubon’s IBAs are chosen based on locations that are habitat for species of conservation concern, range-restricted or concentrated species, and species that are vulnerable due to their occurrence in high densities (e.g. Tri-colored blackbird colonies).

Our final list of grassland bird IBAs have at least one of the following criteria: at least 40% of their total acreage identified as grassland vegetation, containing over 10,000 grassland acres, high numbers of grassland focal species observed within the IBA. Table X includes a summary of the data used to choose areas with important grassland bird habitat in California. Figure 2 is a map of the following selected grassland IBAs.

Audubon’s IBA program website has multiple opportunities for getting involved in bird conservation in California. Documentation of the occurrence of grassland birds in these important grassland areas is a high priority. More information can be found at the website:

http://web4.audubon.org/bird/iba/index.html (accessed June 24, 2014)

Summary of Important Grassland Bird Habitat Areas (based on Audubon’s IBA program)

Aguanga Area

Site: Dominated by Temecula and Wilson creeks, which drain the north face of Palomar Mountain and the southwestern slope of the San Jacinto Mountains.

Grassland Species: Burrowing Owl, Ferruginous Hawk, Golden Eagle, Grasshopper Sparrow, Loggerhead Shrike, Northern Harrier, Prairie Falcon, and Tricolored Blackbird occur in this area.

Byron Area

Site: Encompasses a large patch of grassland and constructed wetlands in the East San Francisco Bay Area; the grasslands lie in the ecotone between the eastern shoulder of the Diablo Range and the floor of the Central Valley, west of Byron Highway and south of Highway 160.

Grassland Species: Burrowing Owls utilize the raised, sandy spots here for nesting, their habitat having been eliminated from much of the valley floor. Swainson's Hawk nest in scattered clumps of trees (mainly planted Eucalyptus), about the closest they breed to the Bay Area. Ferruginous Hawk, Golden Eagle, Loggerhead Shrike, Northern Harrier, and Tricolored Blackbird also occur in this area.

Camp Pendleton

Site: Located in the Santa Margarita River watershed, bordered by San Mateo Creek to the north and encompassing Sandy Creek, De Luz Creek, and O'Neil Lake.

Grassland Species: The extensive grassland supports multiple territories of Northern Harrier. Ferruginous Hawk, Golden Eagle, Grasshopper Sparrow, Loggerhead Shrike, and Savannah Sparrow also occur in this area.

Cape Mendocino Grasslands

Site: One of the largest expanses of grassland in northwestern California, reached via a long, sinuous road west from Hwy. 101 and bounded by the King Range Wilderness Area (a.k.a. The Lost Coast, BLM) to the south.

Grassland Species: Cape Mendocino grasslands support colonies of nesting Grasshopper Sparrows and Horned Larks, both regionally rare breeders. Burrowing Owl, Ferruginous Hawk, Golden Eagle, Northern Harrier, and Tricolored Blackbird also occur in this area.

Carrizo Plain

Site: Encompasses 162,000 acres along the San Andreas Fault between the Central Valley and the coast, and includes two large valleys (Carrizo Plain and Elkhorn Plain), a massive seasonal alkali lake (Soda Lake), and low, rolling hills of grass and arid scrub.

Grassland Species: Breeding Northern Harrier, Golden Eagle, Prairie Falcon, and Burrowing Owl, all of which have become localized or have all but disappeared from the San Joaquin Valley, thrive at Carrizo. Swainson's Hawk was known as a breeder from the San Juan Creek drainage just west of Carrizo (Walton 1978), and could return to the area. Wintering Golden Eagle and Ferruginous Hawk occur in one of their last strongholds toward southern California. Burrowing Owls breed on the plain in large numbers.

Grasshopper Sparrow, Loggerhead Shrike, and Tricolored Blackbird also occur in this area.

Cuyama Valley

Site: Extends for about 15 miles along the middle Cuyama River, which flows west through the Coast Range about 80 miles inland of Santa Maria; its habitat represents an intersection of Central Valley, Mojave Desert, and coastal influences.

Grassland Species: The valley floor sustains breeding colonies of Tricolored Blackbird and Burrowing Owl, and the low hills support nesting Prairie Falcon. Ferruginous Hawk, Golden Eagle, Grasshopper Sparrow, Horned Lark, and Loggerhead Shrike also occur in this area.

Grasslands Ecological Area

Site: A 160,000-acre mosaic of Central Valley floor habitats within Merced County between I-5 and I-99 in the northern San Joaquin Valley, west of a line between Modesto and Fresno; part of the historic floodplain of the San Joaquin River.

Grassland Species: This area consistently hosts large numbers of breeding Tricolored Blackbirds, which average 5-10,000 breeding birds, with over 60,000 typically wintering. Its open pastures and fields host breeding Grasshopper Sparrows in the spring. Dozens of pairs of Swainson's Hawk breed. Burrowing Owl, Ferruginous Hawk, Loggerhead Shrike, and Northern Harrier also occur in this area.

Jepson Grasslands

Site: Adjacent to the Jepson Prairie Preserve about 15 miles east of Fairfield, centered on the intersection of Highways 12 and 113; features a cluster of dry agricultural fields and pastureland at the edge of the Delta ecosystem.

Grassland Species: These grasslands have emerged as a key site within the Bay Area and Delta for several declining grassland species, notably for breeding Swainson's Hawk and Northern Harrier. Burrowing Owl and Loggerhead Shrike, both widely extirpated in the region, are resident. Ferruginous Hawk, Golden Eagle, Grasshopper Sparrow, Prairie Falcon, Savannah Sparrow, and Tricolored Blackbird also occur in this area.

King City Grasslands

Site: Encompasses the best remaining riparian habitat on the middle Salinas River forming a corridor of habitat that includes San Lorenzo County Park, as well as extensive arid grasslands to the east.

Grassland Species: The grasslands support a wide variety of species that are otherwise rare in the region, including Tricolored Blackbird, Loggerhead Shrike, and Grasshopper Sparrow. Several of the shallow canyons have populations of Burrowing Owl, the last remaining stronghold in the Central Coast. Raptors are well represented by breeding populations of Northern Harrier, Golden Eagle, and Prairie Falcon, with good numbers of Ferruginous Hawks arriving each winter. Loggerhead Shrike is still a common resident here. In winter, influxes of Horned Lark are scattered widely.

La Grange/Waterford Grasslands

Site: Extending between the Stanislaus and Tuolumne rivers, the eastern border of the same counties feature flat, extensive grassland dotted with vernal pools grading into a broad band of oak savannah to the east, at the toe of the Sierra foothills.

Grassland Species: The grasslands surrounding Cooperstown support a high diversity of breeding and wintering raptors, especially Ferruginous Hawk, Golden Eagle, and Burrowing Owl, as well as breeding colonies of Tricolored Blackbird. Grasshopper Sparrow, Loggerhead Shrike, and Northern Harrier also occur in this area.

Lone Willow Slough

Site: A 30,000-acre area northeast of Firebaugh, between Grasslands Ecological Area and Mendota Wildlife Area; habitat includes vernal pool-rich grassland, alkali scrub and freshwater marsh, and riparian woodland

Grassland Species: This area supports a sizable population of breeding Swainson's Hawks, of which 50-100 birds have been observed at summer roosts in cottonwoods along the slough. The extensive grasslands may be one of the only places on the San Joaquin Valley floor that could potentially support Grasshopper Sparrow, though more fieldwork is needed. Burrowing Owl, Ferruginous Hawk, Loggerhead Shrike, Northern Harrier, and Tricolored Blackbird also occur in this area.

Merced Grasslands

Site: Uncultivated Central Valley floor of eastern Merced County with the largest and most varied complex of vernal pool-rich grassland in California; located along the base of the Sierra foothills, nearly to the San Joaquin River north of Fresno, though its widest portion is currently centered along La Paloma Road in eastern Merced County.

Grassland Species: Golden Eagles occur in high concentrations. In winter, Savannah Sparrow and Horned Lark occur in large flocks. Burrowing Owl, Ferruginous Hawk, Grasshopper Sparrow, Loggerhead Shrike, Northern Harrier, Swainson’s Hawk, and Tricolored Blackbird also occur in this area.

Mount Hamilton Range

Site: Eastern slopes of the Coast Range separating the east San Francisco Bay Area and the Central Valley; largely blue oak savannah vegetation.

Grassland Species: One of the highest densities of breeding Golden Eagles in California; Northern Harrier, White-tailed Kite, Burrowing Owl, Loggerhead Shrike, Grasshopper Sparrow, Tricolored Blackbird, Prairie Falcon, and in winter, good numbers of Ferruginous Hawk are present.

Panoche Valley

Site: West of I-5, due west of Fresno, in the western San Joaquin Valley of San Benito County.

Grassland Species: The broad Panoche Valley is notable for its high concentrations of wintering raptors and sparrow flocks, which join a resident population of Burrowing Owl and other grassland species. Grasshopper Sparrows, which have been virtually eliminated as nesters elsewhere in the San Joaquin Valley, breed here. Hundreds of Tricolored Blackbirds breed each year at Little Panoche Reservoir. Ferruginous Hawk, Golden Eagle, Loggerhead Shrike, Northern Harrier, and Prairie Falcon also occur in this area.

Puente-Chino Hills

Site: Low (<1500') range of hills on the eastern side of the Los Angeles Basin bordered by Orange County to the south; habitat includes extensive areas of grassland and coastal sage scrub.

Grassland Species: Rare and local breeding species maintain small, remnant populations here, including Northern Harrier and Golden Eagle. Grasshopper Sparrows are widespread throughout the hills. Locally-scarce grassland birds include Prairie Falcon in the south and Ferruginous Hawk in the east. Loggerhead Shrike also occur in this area.

Sacramento-San Joaquin Delta

Site: Centered on the southwest arm of Sacramento County, roughly halfway between Sacramento and the East Bay cities of Antioch and Concord.

Grassland Species: The regularly-flooded agricultural lands of the Delta support a rich wintering bird community, including Swainson's Hawk (breeding and wintering). Holland and Palm tracts host large numbers of Swainson's Hawk and Tricolored Blackbird. Loggerhead Shrike and Northern Harrier also occur in this area.

Salt Spring Valley

Site: Due east of Stockton at the base of the Sierra foothills, separated from the Central Valley by Gopher Ridge, a low northwest-southeast-trending range covered with oak woodland.

Grassland Species: The area may be a center of abundance for the remaining Burrowing Owl in the central Sierra Foothills, and supports nesting Loggerhead Shrike, which has also recently declined sharply in the foothills. Ferruginous Hawk, Golden Eagle, Grasshopper Sparrow, Northern Harrier, Prairie Falcon, and Tricolored Blackbird also occur in this area.

San Antonio Valley

Site: Encompasses the land between the San Antonio and Nacimiento Rivers from their headwaters in the Santa Lucia Mountains to their confluence with the upper Salinas River, and an extensive riparian corridor on the Salinas River between the two confluences.

Grassland Species: The grassland and rocky gorges have active Prairie Falcon nests. Ferruginous Hawk, Golden Eagle, Grasshopper Sparrow, Loggerhead Shrike, Northern Harrier, and Tricolored Blackbird also occur in this area.

San Emigdio Mountains

Site: Encompasses primarily all of the San Emigdio Mountains, which run east to west between the Carrizo Plain to the west and the Tehachapi Mountains to the east.

Grassland Species: One of the largest colonies of Tricolored Blackbirds in southern California breeds in the marshes within San Emigdio Canyon on Wind Wolves Preserve. The grasslands on the lower slopes, some of the most extensive in southern California, support Grasshopper Sparrow and a large and diverse grassland raptor population, including Burrowing Owl, Barn Owl, Northern Harrier, Prairie Falcon and Golden Eagle. Ferruginous Hawk and Loggerhead Shrike also occur in this area.

San Jacinto Valley

Site: Dominated by the floodplain of the San Jacinto River, which runs northwest from the base of the San Jacinto Mountains.

Grassland Species: The marshes of the San Jacinto Wildlife Area (SJWA) support hundreds of pairs of Tricolored Blackbird. Dozens of Ferruginous Hawks, one of the largest concentrations in the state, winter in this area. Golden Eagles regularly occur here, and Burrowing Owls have nested at the SJWA and elsewhere in the Valley. A sizable northward movement of Swainson's Hawks occurs in the springtime. Grasshopper Sparrow, Loggerhead Shrike, Northern Harrier and Prairie Falcon also occur in this area.

Shasta Valley

Site: Bisected by I-5 just south of the Oregon border in the long shadow of Mt. Shasta; habitat is largely grassland (including remnant native grasses), juniper woodland, scattered wetlands, and cropland.

Grassland Species: The grasslands have held some of the region's few nesting pairs of Burrowing Owl. Ferruginous Hawk, Golden Eagle, Loggerhead Shrike, Northern Harrier, Prairie Falcon, and Tricolored Blackbird also occur in this area.

Taft Hills

Site: Low, rolling hills at the eastern edge of the Temblor Range in the southwestern San Joaquin Valley, extending along the far western border of Kern County from Maricopa and Taft northwest to just north of McKittrick; Buena Vista Creek (usually dry) drains the eastern flank just north of Taft.

Grassland Species: A distinct, intact natural community of birds occurs in this area, including Burrowing Owl, Ferruginous Hawk, Golden Eagle, Loggerhead Shrike, breeding Prairie Falcon, and Tricolored Blackbird.

Vandenberg Air Force Base and Santa Ynez Estuary

Site: Covers nearly 100,000 acres on the coast of northern Santa Barbara County, just north of Point Concepcion.

Grassland Species: The tidal marsh and mudflats at the mouth of the Santa Ynez River support a colony of saltmarsh-nesting Savannah Sparrows. Open-country birds occur here in numbers unprecedented elsewhere on the Central Coast, with Grasshopper Sparrow breeding and Ferruginous Hawk and Burrowing Owl occurring in winter. Loggerhead Shrike, Northern Harrier, Prairie Falcon, and Tricolored Blackbird also occur in this area.

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VI. Conservation Action Recommendations

This chapter provides specific recommendations for grassland habitat activities throughout the state. They consider habitat protection and restoration, land management, research and monitoring, and policy action. Conservation organizations, agencies, scientific researchers and the public provided the information used in developing this chapter and most recommendations were derived from the most recent scientific data and analyses available. Unless otherwise referenced, most information from this section is derived from the focal species accounts or an initial review of the literature describing projects within California on management strategies for grassland bird conservation. Some, however, rely upon well-informed assumptions that require more scientific investigation. Standardized monitoring and adaptive management will test and develop these assumptions, continually improving our knowledge of conservation and restoration science.

These recommendations seek to reverse the current declines of many grassland bird populations. By restoring healthy, stable populations, we will avoid the expensive and intrusive last resort of listing more species as threatened and endangered. We hope that these recommendations will galvanize and guide conservation organizations, project funding, and the actions of land managers and owners across the state. All of the following goals and objectives or recommendations seek to fulfill CalPIF’s central mission, which is to promote conservation and restoration of grassland habitat sufficient to support the long-term viability and recovery of native bird populations.

Grassland Habitat Protection Recommendations

A number of factors come into play when considering whether or not a parcel of grassland habitat should be targeted for conservation and protection, ranging from societal and economical to ecological benefits. From the ecological perspective, we recommend considering the following factors:

Patch size: is the grassland site in consideration large enough to support grassland-dependent wildlife species?

Connectivity: will protecting the grassland site link together habitat pieces that would otherwise be isolated?

Habitat Integrity: Is there a relatively high cover of native grassland plan species present, or is the site overrun with noxious weeds?

Habitat value: Is the grassland site already providing habitat for grassland focal species and other wildlife? And what is the potential to improve its habitat value?

Below are conservation strategies that may be employed to help conserve existing grasslands:

1) Williamson Act

One of the oldest agricultural conservation programs, the Williamson Act (also known as the California Land Conservation Act of 1965) is a land protection program that reduces property taxes for private owners of California rangeland and farmland. Under the program landowners enroll their property and agree to maintain it in agricultural production for a minimum of 10 years. Approximately 15 million acres of California ranch and farm land were enrolled in the Williamson Act. It involved state reimbursement to the majority of California counties for this tax reduction until budget year 2008-2009 when funding for the program was severely cut. Not restoring funding for the Williamson Act will potentially cause ranchers and farmers to sell land with a high potential for conversion to urban development (Wetzel et al. 2012).

2) Conservation easements

In order to preserve grassland habitat, some private landowners choose to place a conservation easement on their property. A conservation easement is a voluntary agreement between a landowner and a qualified land trust, conservation group or government agency regarding future uses of the land in order to protect its conservation values. It allows private landowners to continue to own and use their land, and they can also sell it or pass it on to heirs. There are different types of conservation easements depending on the landowner’s individual situation. Agricultural conservation easements allow landowners to protect their property to ensure that future generations can continue to ranch or farm. The following is a list of sites with more information:

National Conservation Easement Database (Provides general information about conservation easements)

http://conservationeasement.us (accessed April 2014)

California Rangeland Trust

http://www.rangelandtrust.org (accessed April 2014)

American Farmland Trust

http://www.farmland.org (accessed April 2014)

Trust for Public Land

http://www.tpl.org (accessed April 2014)

3) California Conservation Banking Program

The California Conservation Banking Program, established in 1995, is the first program of its kind in the U.S. and gives ranchers and other landowners an opportunity to be compensated for managing their land to benefit wildlife. Conservation banking provides a larger scale alternative to the smaller project-by-project based mitigation approach for the destruction of at-risk species habitat. Grassland conservation banks in California are publicly or privately owned lands that are protected in perpetuity by fee title or conservation easement and managed to provide habitat for multiple species such as Burrowing Owl or Swainson’s Hawk. Banks are sometimes created within both the larger Natural Community Conservation Plans (NCCP) or Habitat Conservation Plans (HCP). Conservation banks sell or trade at-risk species habitat credits to project developers who need to satisfy legal requirements for mitigating environmental impacts within the service area established for the Bank.

In order to ensure the viability of this program as an economic option for landowners, new conservation bank policies should include clear and consistent standards that require regional prioritization and monitoring with plan-based goals and objectives that would maximize the potential ecological benefit. Senate Bill 1148 (effective 2013) created a clear regulatory framework for the program and included a structure for agency staff funding (White 2013). Funding for program-dedicated agency staff will smooth the coordination of the review and approval process and allow supervision of the monitoring results (Bunn et al. 2013).

More information on Conservation Banks is available at the California Department of Fish and Wildlife website:

https://www.dfg.ca.gov/habcon/conplan/mitbank (accessed July 2014)

and the U.S. Fish &Wildlife Service Sacramento Office

http://www.fws.gov/sacramento/ES/Conservation-Banking/Home/es_conse-banking.htm (accessed July 2014)

4) CRP – small program only in the northern central valley?

5) USDA Farm Bill Programs administered by Natural Resources Conservation Service for land conservation and wildlife habitat improvement.

There are a variety of USDA programs available to assist landowners with their conservation goals. The 2014 Farm Bill included some changes in the structure of various programs but essentially includes the same type of financial assistance to help plan and implement conservation practices on agricultural or working grasslands.

The following changes within the 2014 Farm Bill are not retroactive and do not affect current contracts with the NRCS. The Wildlife Habitat Incentive Program (WHIP), which was a program for landowners to develop and improve wildlife habitat on agricultural land, has been discontinued. However, the goals of WHIP are now included within the Environmental Quality Incentives Program (EQIP). The new Agricultural Conservation Easement Program (ACEP), which includes agricultural land and wetland reserve easements, is the new program for the now discontinued Wetlands Reserve Program (WRP), Grassland Reserve Program (GRP), and Farm and Ranch Lands Protection Program (FRPP).

There is more information on these programs in Table 4 and on the website for the U.S. Department of Agriculture -- Natural Resource Conservation Service (NRCS)

http://www.nrcs.usda.gov

American Farmland Trust showcases ranchers and farmers that are taking advantage of Farm Program opportunities to move forward with their environmental stewardship goals and at the same time create a more sustainable and profitable farming operation. Tim Koopman, Alameda County, has used a combination of farm programs, Grassland Reserve Program, EQIP, and Rangeland Trust Conservation Easements as well as a partnership with his local Audubon chapter to keep a family cattle ranching operation not just sustainable but thriving in an area where development continues to be a serious threat. http://www.farmland.org/programs/campaign/california-voices.asp

Monitoring and Research Recommendations

Specific goals and objectives are an essential part of any monitoring or research plan. Below are basic goals for grassland bird populations in California and some measureable objectives that will help achieve these goals.

Goal 1) Evaluate grassland bird distribution and population status state-wide

Objective 1.1. Provide data on distribution and population status. Identify areas of grassland bird abundance.

In order to successfully protect and expand native grassland bird populations, managers must have the most recent data available on populations and their habitat needs. Standardized scientific monitoring of populations will provide decision-makers with these essential tools. Very little is known or published about grassland birds in California regarding habitat characterization.

Objective 1.2. Measure reproductive success and survival rates when monitoring populations, assessing habitat value, and developing conservation plans.

The number of young produced in a bird population (reproductive success) critically influences a population’s presence, health and sustainability in an area. Reproductive success is a primary demographic parameter that provides critical information for understanding patterns of population change. Hence, these data can be used to understand trends, focus conservation action and funds, and identify hypotheses for further evaluation. When fewer than 20% of nestlings survive to fledge young, nest success is considered poor and probably indicates a nonviable population. Nur et al. (2004) and Shaffer (2004) describe feasible analytical techniques for monitoring nest survival as a function of covariates such as environmental and/or temporal variables. These variables may be quantitative (e.g., vegetation measurements, nest height, date, nest age) or qualitative (e.g., habitat type, management practice). However, to adequately measure annual productivity, investigators should not stop at calculating nest success alone (Thompson et al. 2001, Anders and Marshall 2005); instead we should also strive to accurately 1) count re-nesting attempts after nest failure, 2) count number of young fledged per successful nest, 3) measure double brooding frequency by following color-marked birds throughout the breeding season.

Monitoring annual adult survival is important in the same way as discussed for reproductive success; population trends can thus be better understood from monitoring the interaction of these demographic parameters. Survival can only be confidently calculated for adults after at least four years of mark/recapture data (such as mist-netting) have been obtained (Nur et al. 1999). Research seeking to determine productivity for a breeding population should include at least four years of nest-searching and/or mist-netting.

Objective 1.3. Conduct intensive, long-term monitoring at selected sites. In order to analyze trends, long-term monitoring should continue for more than five years.

Long-term data are vital to deciphering the difference between a true population decline and a natural fluctuation in population size. Because conservation dollars are limited, the best possible data on population trends are needed so as not to squander scarce resources on a species that is not truly in decline. Long-term monitoring should be conducted at reference sites that embody the characteristics restoration efforts strive to recreate. Additionally, long-term monitoring at key experimental sites can test the assumptions that currently drive restoration and management practices. Intensive monitoring includes collecting data on primary demographic processes and associated habitat characteristics and seeks to identify causal connections between habitat variables and species viability. Biologists collect data on reproductive success, breeding densities, parasitism, survival, vegetation data, suitable habitat requirements, and general life-history information. Managers can employ these data to make well-informed, adaptive management plans.

Objective 1.4. Resume BBS routes that have been discontinued.

Breeding Bird Surveys (BBS) provide the best long-term, broad scale data for tracking population trends for breeding birds in North America. However, many of California's BBS routes which include significant amounts of grassland habitat have been abandoned by BBS volunteers. This problem is particularly severe in the mid-southern San Joaquin Valley. As much of the grassland and mixed grassland/atriplex habitats in that region were converted to intensive agriculture (cotton and other row crops, orchards, vineyards), the routes apparently became less interesting to volunteers and the routes were abandoned. Many of those abandoned routes still include large areas of grassland. Without continuing data collection, we have no way to document the full effects the loss of these grasslands or the degree to which birds continue to use the remaining habitats.

To address this, we identified 13 BBS routes which have been abandoned, but could provide very useful population data if volunteers were willing to adopt these routes. We examined historical data from all abandoned California BBS routes and ranked the routes based on the average number of focal grassland species detected on these routes at a significant level (average of >3 individuals of a given species per run). The routes below (listed from north to south) all detected significant numbers of at least six grassland focal species over the years the route was run.

(BBS ROUTE TABLE)

Objective 1.5. Document reporting of citizen-science monitoring efforts that increase coverage of grassland habitats to better understand where grassland bird species are abundant.

Utilize new methods of citizen-science reporting using eBird, iNaturalist and Important Bird Area websites to collect data on the distributions of grassland bird species. Encourage Audubon chapters that have a local priority grassland bird area to report their observation data.

Goal 2) Develop a series of monitoring and research projects that assess factors that influence focal species status state-wide

Objective 2.1. Determine sensitivity of California’s grassland birds to grassland patch size.

Studies done in other grassland areas in North America have shown that some grassland species show sensitivity to grassland patch size (e.g. Herkert 1994, Johnson and Igl 2001, Ribic et al. 2009). In Herkert’s study in Illinois, he found that Grasshopper Sparrows were not present in grassland patches smaller than 30 hectares (74 acres) despite the fact that their published average territory size is only about 0.3 ha (0.75 acres). In other words, Grasshopper Sparrows needed a patch size some 100 times their average territory before settling. It is unknown if California populations respond in a similar manner, but determining this will clearly affect the outcome of the conservation strategies we ultimately pursue.

Objective 2.2. Determine if grassland birds select for or have increased productivity/ survivorship in grasslands with higher levels of native plants. Is there a threshold percent of native plants that determines whether a grassland bird species is reproductively successful? Do grassland birds respond to native plant enhancement/restoration projects?

No bird data for grasslands exists before the great invasion of exotic annuals occurred in the 1800’s. Thus, we have little knowledge of what the grassland bird community may have looked like before the transformation. However, it would be well worth our while to determine if native grasslands have any benefits for the remaining grassland species. There is some evidence that grassland bird species respond to the level of native plants in other regions but very few studies looking at this question in California (Gennet et al. 2017, Goerrissen 2005). Answering this question is especially important as many refuges, parks, and ranches move towards managing for native perennial grasses and forbs, often at great expense. If grassland birds do show a consistent positive response to native grasslands, this could add another line of evidence to justify expensive restoration projects across the state. See restoration and invasive plant sections for more discussion.

Goal 4) Expand research and monitoring of selected special-status species to address pressing conservation issues.

Goal 5) Evaluate consequences and benefits of various Farm Programs and management strategies

a) Prescribed grazing (NRCS practice code 528), by NRCS definition, involves managing the harvest of vegetation with grazing and/or browsing animals in order to achieve a desired objective. It can be used as a tool to manage undesirable and invasive plants like shrubs or weedy mustards as well as increase or maintain the native forb component of California grassland. Grazing variables that are important to remember when planning a grazing treatment include stocking rates, seasonality, duration, and livestock species (Briske et al. 2011). Grassland bird responses to grazing are known to be site and species specific (Derner et al. 2009, Krausman et al. 2011)

b) Prescribed burning (338) is the application of controlled fire to a pre-determined area. Although this management method can be used to control weeds and possibly enhance the native component of the grassland, spring or summer burning should be avoided due to the cost to ground-nesting birds. California may have other obstacles to burning such as air pollution restrictions and safety concerns.

c) Brush management (314) is the management or removal of invasive woody plants. Burning, herbicide and mechanical methods are used. Spring and summer timing should be avoided due to the cost to breeding birds.

d) Range planting (550) is the establishment of adapted perennial or self-sustaining vegetation such as grasses, forbs, legumes, shrubs and trees depending on the reference state or target ecological site description. If the planting involves non-native plants as part of a desired new plant community, care should be made to ensure that all species are not invasive. Landscape level planning should be used whenever possible to avoid impacting nearby important native grassland areas.

e) Herbaceous weed control (315) is the removal or control of herbaceous weeds including invasive and non-native plants. Limit pesticide and herbicide use to least toxic alternatives both within the grassland and on adjacent cropland or orchards due to the effect of chemical drift.

Grassland Habitat Restoration Recommendations

1) Strategies to maintain and restore native grassland across the California landscape

The current California grassland mix of naturalized exotic and native plants provides one of the most interesting challenges of landowner stewardship today. Management to enhance or maintain native grassland is a common goal of land managers but it is necessary to realize that attempting to return to a pristine, exclusively native ecosystem is unrealistic in the majority of grassland areas in California. Within reach may be the goal of ecosystem restoration or “creating a landscape that is more weed-resistant, maintains its productivity over time and other ecosystem services, and is somewhat tolerant or resilient to a variety of stresses” (Stromberg et al. 2007 p. 254) and that contains greater native plant diversity and provides higher-quality habitat for wildlife.

Any restoration project should be part of an overall vegetation management plan that identifies site potential and includes both adaptive management considerations and a monitoring plan with clear and measurable objectives for the area under consideration . More and more restoration practitioners are recognizing the importance of planning for individual site characteristics and, when resources allow, identifying in advance ecological site descriptions and specific management practices that benefit native species (Spiegal et al. 2014). Monitoring for grassland bird species should be included in any restoration project as one measure of success. Species with direct associations to a particular vegetation or habitat type, such as grassland-obligate species, are likely to be strong indicators of grassland ecosystem health (Carignan and Villard 2002).

That being said, restoration can be approached in two different ways, active restoration or passive restoration, depending on the size or area to be restored, site characteristics, and resources available for restoration (Stromberg et al. 2007). Active restoration implies native species seeding or planting and ongoing weed removal or eradication. Passive restoration involves applying lower cost standard management tools, such as burning or grazing, to specific restoration goals. Passive restoration can be less expensive than active restoration and, importantly, can be applied over large areas. A vital restoration consideration is whether there is an adequate in-situ source of native seed, either from plants adjacent to the restoration site or within the site’s soil seed bank. Studies have found that many native species are strongly seed-limited and that when native seed is added to a seed-poor site, cover of native species increases significantly (Corbin et al. 2007). Grasslands in California dominated by non-native annual grasses appear to be here to stay, however, and will likely persist in a stable state until active restoration is used that includes native species (Stromberg et al. 2007).

a) Passive restoration using targeted grazing management or prescribed burning

Passive restoration tools like livestock grazing are commonly used across grasslands in California. Cattle grazing can be employed as a management tool for enhancing wildlife habitat and promoting native plant abundance, and is considered to work by changing the height and patchiness of the grassland (bare ground) and by removing the grass and promoting the native forb diversity (Weiss 1999, Barry et al. 2011). These kinds of responses, however, are site and time (i.e. season or year of treatment) specific (Huntsinger et al. 2007). For example, studies in central California grasslands have shown that abiotic or soil properties more strongly predict the presence of native plants than cattle grazing on what are quite small and distinctive ecological sites (Gea-Izquierdo et al. 2007). It is also important to note that targeted specialized grazing systems have a spotty record of success with native species enhancement (Stahlheber and D’Antonio 2013). With adequate planning and follow-up monitoring, grazing prescriptions for the control of specific plants can be used to manage unwanted populations of shrubs or noxious weeds. Several of the major valley grassland invasive species can be reduced, if not entirely eliminated, with livestock grazing, e.g., yellow starthistle (Centaurea solstitialis) and medusahead (Taeniatherum caput-medusae) (Jackson and Bartolome 2007).

Prescribed burning in California is a historic and useful if somewhat problematic passive grassland restoration tool. Burning can be used to control woody plant invasion (e.g. Baccharis spp. in coastal prairie) and has been known to reduce non-native annual grass to the benefit of native forbs or wildflowers. Burning reduces non-native annual grass cover and can cause a flush of both native and non-native forbs the following spring. Planning a burn in California, however, can be difficult due to air pollution restrictions and safety considerations. Another complicating factor for this tool is the preferred timing for most weed-control burns, spring or summer, obviously should be avoided to protect grassland bird nesting activity (Reiner 2007). This limits the use of long-term prescribed burning for weed control but allows that fire is still important in the context of a comprehensive native plant enhancement plan.

b) Active restoration of native grasslands using native species planting and ongoing weed eradication

Active restoration requires resource-intensive activities, such as native species planting and ongoing weed eradication. Generally, active restoration is applied to fairly small areas (typically under 100 acres and often much smaller (Stromberg et al. 2007)) and can require substantial financial and labor resources. There are organizations and private landowners restoring native grassland on a small scale. See the resources section for more information on ongoing active grassland restoration sites.

Restoration Resources

California Native Grasslands Association (CNGA)

http://www.cnga.org/

Hastings Natural History Reservation: Landowner’s Guide to Native Grass Enhancement and Restoration, coastal prairie focus

http://www.hastingsreserve.org/nativegrass/grassmanageintro.html

East Bay Regional Park District: Serpentine Prairie Restoration Project

This project involves ongoing active restoration on a small scale of serpentine prairie, a highly native grassland with plants such as the endangered Presidio clarkia, located in the hills of the Eastern San Francisco Bay. Restoration techniques like mowing and tree removal are allowing the renewal of populations of wildflowers endemic to the serpentine soil-type. The project is located on a 6-acre parcel of parkland adjacent to housing developments and other parkland. Funding in 2010 is from a combination of Federal Emergency Management Agency and the Park District’s General Fund.

http://www.ebparks.org/stewardship/plants/serpentineprairie

3) Farm Practices that can maintain a healthy and more native grassland ecosystem

a) Preservation of open grassland

Keeping grasslands in large patches of uninterrupted grassland or pasture is important for the maintenance of a healthy grassland ecosystem. Large areas of grassland reduce the likelihood of the degradation of grassland habitat (e.g. exotic plant invasion, increase in predators, pesticide drift).

b) Invasive plant management

The management of invasive plants and maintenance of native grassland areas are necessary in California to keep healthy grassland bird habitat. Livestock grazing can be important for grassland weed control especially in wetter more productive areas of California with a history of grazing or previous crop cultivation. Although more labor intensive, the mechanical removal of shrubs and trees can control woody plant invasion where fire, herbicide or livestock grazing are not feasible.

Policy action recommendations

1) Economic incentives for farmers and ranchers are needed to prevent large scale conversion and fragmentation of rangeland to almond orchards and other intensive agricultural crops like alfalfa.

2) Continue support for programs discussed in grassland protection strategies.

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VII. Implementation of Conservation Plan Recommendations

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VIII. Outreach and Education

Point Blue Conservation Science is a non-profit organization founded in 1965 as Point Reyes Bird Observatory. Point Blue researches birds and ecosystems, creates management tools, leads field science training programs, and develops and delivers bird science education programs to advance biodiversity conservation in the west on land and at sea. Point Blue is protecting nature’s health for wildlife and people. Point Blue’s new Rangeland Watershed Initiative is an outreach program where Point Blue’s Partner Biologists work collaboratively with NRCS Field Conservationist and ranchers to restore and improve habitat in the watersheds of the Central Valley of California. The Point Blue Partner Biologists provide “value added” assistance by more fully integrating the fish and wildlife disciplines into the planning (including habitat and stream assessments), design, implementation and monitoring of conservation practices on working ranch landscapes.

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IX. Literature Cited

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