Great Lakes Geography
This page provides some food-for-thought on how the geography of the Great Lakes can help concentrate birds - and vagrant birds - depending on the season and weather conditions. It is not meant to be comprehensive. Use these ideas to formulate when and where you can look locally, if your goal is to find something rare or unexpected!
WATERBIRDS
This section shows some examples of how waterbirds are either "pushed" by wind and weather and/or are naturally funneled into the features of the Great Lakes. Not all vagrants realize they are lost however, and are sometimes travelling with migrant groups of local bird species. Be sure to check out some principles of lakewatching to understand other ways migrant waterbirds are concentrated for better study!
Two case studies from Lake Erie:
The tip of Point Pelee is known for good viewing of waterbirds in fall during south or southwest winds. Generally, these birds are present on the productive "western basin" of Lake Erie, and are concentrated closer to shore by the wind direction. As they approach the tip, these concentrated numbers pass close to observers, allowing for close look at study which aids in the detection of unusual birds. Sometimes a secondary flight of birds attempting to move west will fly south down the east side of the point in similar conditions (not illustrated), providing yet another concentrating factor and flightline for birders to scan.
Birders in Buffalo, New York will flock to Lake Erie on strong west or southwest winds in fall to see what is concentrated in the rivermouth or nearby marinas and sheltered locations. This is the longest "run" or "stretch" in the region, and exceptional waterbirds such a Brown Booby, Elegant Tern, Ross's Gull and more have ended up here.
Two case studies from Lake Ontario:
Birders in southern Ontario go to Van Wagner's Beach in fall, where pelagic species may concentrate at the west end of the lake, especially during strong easterly winds (orange arrow). The lakes proximity to the St. Lawrence River and Atlantic Ocean, it is more likely to turn up species such as Manx Shearwater, Razorbill, Leach's Storm-Petrel or Northern Gannet than elsewhere in the region.
Similar effects are possible during west or northwest winds, pushing birds into New York. One element to consider is how geographic features along the Lake - in this case Oswego Harbor - may then "catch" wayward birds looking for a place to settle down (see: Black Skimmer, Yellow-billed Loon, Clark's Grebe, etc.).
Two Case Studies from Lake Superior:
Whitefish Point (orange lines) takes advantage of some of the longest/largest runs in the Great Lakes. It also has a slight local geography boost due to birds closely "rounding" the point, giving local observers a better view to spot and study a potential vagrant. As the largest and westernmost of the lakes, it can also "catch" overland vagrants coming from the west coast or the arctic which likely explains the remarkable number of Ancient Murrelet records among others.
Birders at the west end of the Lake also benefit from similar concentration effects (red lines); however, one would have to wonder how many more jaegers would be seen at Duluth/Wisconsin point if there were fewer points/bays/islands along the south shore.
DIURNAL MIGRANTS
This section discusses birds that like to avoid water are naturally funneled by the Great Lakes depending on their direction of flight. These examples show perhaps the two largest land-funnels in the region; however, keep in mind that birds may be travelling in a a variety of directions for a variety of reasons! The principles of morning flight and hawkwatching provides further thoughts on ways and reasons birds - including vagrants - may be funneled past a lucky observer.
Case Study: Point Pelee
Point Pelee is an exceptional funnel for migrants moving south. The "smart" local birds may be aware it is a "dead end" and skip the point during fall migration, leading to relatively lower numbers of migrants like Blue Jay, Turkey Vulture or Broad-winged Hawk to make the long flight right to the very end when compared to migratory count locations like Holiday Beach to the west. Vagrants however, don't have the same luxury of knowledge and may wander down the tip to check things out - not to mention birds that are not afraid of crossing water.
Another key consideration is that vagrants are also going against the grain, heading south in spring or north in fall, which may be a reason why some of the rarest birds observed at Point Pelee have been during the spring months.
Case Study: Whitefish Point
Is Whitefish Point simply Point Pelee in reverse? Or is Point Pelee the reverse of Whitefish? Whatever the case, the principles are the same. In reverse. WPBO records exceptional concentrations of diurnal migrants in spring, and with those concentrations come vagrants. Yet the vagrant-story kicks it into high gear in the "opposite" season, where mega rare landbirds wander down to greet the steadfast counters stationed there daily despite realativley lower concentrations of similar bird families.
NOCTURNAL MIGRANTS
This section discusses birds that readily migrate at night, finding themselves in the Great Lakes region as the sun comes up - possibly over land or possibly over water. Given the wide array of possible species, all bets are off on how these birds will behave once the sun comes up (i.e., they may begin a morning flight, or find suitable habitat to settle down into) but nonetheless it is worth considering how our geography may concentrate them. To make things easier on us, we're focusing on landbirds and shorebirds in these examples! Also checkout our theories on what causes fallouts, as some of the mechanisms may be similar (yet on a micro-vagrant scale).
Case Study: Long Point
Birds that find themselves over water - but utilize shoreline, marsh or upland habitats - will likely "go with the flow" of their current movement direction (and/or wind direction) until they find a place to put down. Therefore, an observer can make some assumptions about which areas of shoreline are likely to see landfalling birds. Long Point has a particularly large "catchment" area, but also benifits from being a narrow strip of land. Birds which reach the point aren't able to continue "inland" and are concentrated in a small area, perhaps making it easier to then find them.
Case Study: Caribou Island
Perhaps the most dramatic catchment in the Great Lakes, tiny Caribou Island sits alone in the vast waters of Lake Superior. One potential strike against it involves just how remote it is - are all birds within the "catchment" area able to find the island? Birding would also likely be quite hit-or-miss depending on the day or season (remember, looking for rare birds can sometimes be slow). Yet with virtually no coverage, reports of species like Clark's Nutcracker, Black-headed Grosbeak and Baird's Sparrow indicate that remarkable potential exists here.