Notes: About the refuge

Pulled from various pamphlets and brochures found online, mostly by the US Fish & Wildlife from recent publication to more than a decade. Therefore, some accuracy might be challenged, though an effort is made to stay updated.

Exceptional wildlife viewing…


Delaware's single best-known birding site, Bombay Hook National Wildlife Refuge justifies its fame with exceptional bird and wildlife viewing throughout the year.
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Location…


Bombay Hook National Wildlife Refuge is located in central Delaware along the western shore of the Delaware Bay.
Contact information: 2591 Whitehall Neck Road Smyrna, DE 19977 Visitor Center: (302) 653-8322
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Unquestionably the best…


The Delaware Birding Trail says it simply. "Unquestionably Delaware's single best-known birding site, Bombay Hook National Wildlife Refuge justifies its fame with exceptional bird and wildlife viewing throughout the year." Read their write up about Bombay Hook NWR.
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History…


Bombay Hook, (one of over 500 National Wildlife Refuges in the United States) is one of the most important stops along the Atlantic Flyway, a migratory path for waterfowl. Recorded history of the area began in 1679 when the Indian Machacksett, Chief Sachem of Kahansink, sold some marshland called "Boompies Hoock" to Peter Bayard of New Yor for a price of "... one gun, fower hands full of powder, three Mats coats, one anckor of Liquors and one kittle..." Early Dutch settlers cut salt hay from the marsh, trapped muskrats, and hunted waterfowl. The tidal streams that interlace the marsh were plied for fish, crabs, and oysters. The Bombay Hook Refuge, extending for eight miles along the western shore of the Delaware Bay, was established March 16, 1937 as a link in the chain of refuges extending from Canada to the Gulf of Mexico and serves as a sanctuary for migratory waterfowl. History PDF. Soon afterward, Civilian Conservation Corps members began constructing pools for waterfowl habitat as well as buildings to administer the area.
Following establishment of the refuge and through the early 1940s Civilian Conservation Corps members based at Leipsic constructed dikes and buildings on the refuge.
With the onset of World War II, the Army Air Corps based at Dover used parts of the refuge for experimentation and training in air-to-ground rockets.
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Viewing wildlife…


Bombay Hook is a great place to study and photograph nature, and to view wildlife in unspoiled surroundings.
Visitors may drive, bicycle or walk the public tour route, a 12 mile round-trip traversing the many refuge habitats. Along the route are five nature trails and three observation towers, each overlooking a fresh water impoundment.
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Time for visit…


Centered around an Auto Tour loop road that traverses a cornucopia of habitats, including fresh and salt marshes, ponds, mudflats, woodlands, and fields.
You should plan an absolute minimum of two hours for a visit here; four is much better, and you could easily make multiple trips over several days before really getting a feel for the varying diurnal and tidal rhythms.
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Visitor Center…


Open fields and plantings attractive to native wildlife surround the Visitor Center. Pick up a copy of the Auto Tour pamphlet, which includes a detailed map, and much useful information. The numbers in the following paragraphs refer to the tour stops in the brochure.
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Migratory flyway…


Situated on the Atlantic migratory flyway, Bombay Hook refuge has become increasingly important as a stopover for migratory birds, as habitat elsewhere has been destroyed. It is known among birders as an international hotspot and is recognized as one of America's 100 'Important Bird Areas' by the American Bird Conservancy.
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Breakdown of refuge…


Much of the 16,251 acres of the refuge remains pristine. 13,000 acres are tidal salt marsh, considered to be Delaware's most valuable wildlife habitat. Impounded fresh water pools and brushy and timbered swamps cover about 1,100 acres; agricultural fields cover another 1,100 acres; and timbered and grassy upland covers the other 1,100 acres. The general terrain is flat and less than ten feet above sea level.
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Habitat diversity…


Such diversity of habitat has resulted in an abundance and diversity of wildlife: 278 species of birds are found on the refuge; 103 of those species are known to breed here.
In addition to the birds, 34 species of mammal, 14 species of amphibians, 21 species of reptiles and 21 species of fish are found on the refuge.
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Fresh Water Impoundments...


Raymond Pool, first encountered on the Auto Loop, is one of four freshwater impoundments on the refuge. These impoundments provide diverse feeding, roosting, and nesting habitat for waterfowl and shorebirds.
The ability to manipulate the water levels of these pools is the key to creating necessary habitats. The level of the pools is maintained by the use of water control structures (the yellow bar structure).
In spring, excess water in the pool is released to the salt marsh (by pulling out the stop logs) thus lowering the water level to create a habitat conducive to the wading birds.
During the summer emergent plants thrive and produce seed in the shallow waters and exposed pool margins.
In the fall adequate rainfall permits water levels to be gradually raised and flood the seed bearing plants. The flooding provides suitable conditions for waterfowl to feed on the plants, thus maximizing the food supply.
The common aquatic plants found in the pools include wild millet, three square, bull rush, cattail, pond weed, widgeon grass, and wild rice.
 The most common fish species include white perch, shad, carp, and the American eel.
The river otter, a rare fur-bearer in Delaware, also makes its home in these impoundments.
The freshwater impoundments on the Bombay Hook Refuge were built over a 22-year period: Raymond Pool (1939) 95 acres; Shearness Pool (1956) 560 acres; Bear Swamp Pool (1961) 240 acres; and Finis Pool (1944) 205 acres. The salinity level in the fresh water impoundments is under 6 parts per thousand, while the brackish and salt marsh levels are 7-20 parts per thousand. (Sea water is 35 parts per thousand.)
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Tidal Salt Marsh...


The tidal salt marsh portion of the refuge comprises approximately 80 percent of the refuge. Of all the different types of habitat within Bombay Hook, this is the most vulnerable and fragile. It is also the least appreciated.
The salt marsh serves as a nursery area for valuable sport and commercial fish, as well as a supplier of organic material in the form of decomposed plants, which form the basis for numerous food chains in the river, bay, and ocean. Because the area is tidal, a constant circulation of nutrients takes place.
There are two types of tidal salt marsh found at Bombay Hook. One is the "high marsh" which is flooded only during extremely high "spring" tides or a very bad storm. Plants characteristic in this marsh are Spartina patens, commonly called salt meadow cordgrass or salt marsh hay, and Distichlis spicata or salt grass.
The other type of tidal salt marsh is the "low marsh" which is flooded during every high tide. Spartina alterniflora or salt marsh cord grass is common here.
A variety of waterfowl nest in the" marsh. These include black duck, mallard, gadwall, and blue-winged teal. A large shorebird, the willet, nests throughout the marsh in abundance.
Since about 1980 the fall and winter snow goose population at Bombay Hook has increased dramatically. Snow geese have the tendency to feed in large groups and cause "eat-outs" in the salt marsh. For this reason there is a managed snow goose hunt to keep the flocks dispersed around the refuge, thus lessening the impact on salt marsh grasses.
The mud and reed mounds scattered across the tidal salt marsh are muskrat houses. The muskrat makes its home in these marshes throughout the year. Muskrat trapping by permit is allowed in areas of the marsh where muskrats are abundant. This prevents damage to the marsh plants as well as refuge dikes which can occur through the burrowing activities of an over-population. Other marsh occupants may vary with the changing seasons.
The fish and shellfish populations in the marsh creeks include menhaden, drum, fiddler crab, blue crab, oyster, and clam.
Dike roads give the opportunity to view otherwise inaccessible marsh, and the visitor may also take advantage of a boardwalk trail near Raymond Pool. This trail will provide you with a closer glimpse of the salt marsh and open pools frequently visited by shorebirds.

Raymond Pool…


The best birding at Raymond Pool is usually to be found along the long, straight stretch of dike road (Tour Stop #3) that borders the northeast edge of the pool, beginning about 1 mile from the visitor center. Note that along Raymond Pool, as in most of the refuge, the dike road divides the freshwater impoundment from tidal saltmarsh.
Raymond Pool is the single most reliable spot in Delaware to find American Avocets and is often loaded with other shorebirds and waterfowl in season.
Lighting here is most favorable in the morning. The number of shorebirds can vary dramatically over the course of the day so a revisit four to six hours later may yield different species and numbers.
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Raymond Pool observation tower…


Other noteworthy areas around Raymond Pool include the observation tower, a short walk from the first parking area on the left (N) side of the road, and…
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Raymond Pool boardwalk…


… the boardwalk trail, which enters the woods on the right side of the road, just a few hundred yards beyond the tower parking lot.
The woods at the beginning of the boardwalk trail can be particularly good for migrant songbirds. The boardwalk trail itself is a great place to see breeding Marsh Wrens and Seaside Sparrows and to listen for rails. Both of these spots are reached on the one-way portion of the Auto Tour before Tour Stop #3.
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Shearness Pool…


Shearness Pool hosts a great variety of waterbirds, as does the open area of salt marsh to its east, called Leatherberry Flats (Tour Stop #5). The Snow Goose spectacle here from late October into midwinter is often stunning and Bald Eagles are frequently seen here at all seasons.
Leatherberry Flats can appear as a huge brackish pool, or as a vast mudflat, depending on wind and tide.
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Bear Swamp Pool…


Bear Swamp Pool, which hasn't had bears for a very long time, does tend to have lots of birds.
Traditionally productive areas include the SE (Tour Stop #7) and NE corners of the large impoundment, where shorebirds, ducks, and waders are often numerous.
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Finis Pool...


Finis Pool (Tour Stop #13) presents a very different face of Bombay Hook - a smaller, freshwater pond with a luxuriant growth of aquatic plants, surrounded by tall deciduous woods .
Finis Pool is the freshest of the impoundments on the refuge and provides a great variety of plant and animal life.
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The woodland...


A wide variety of mammals frequent the refuge's woodlands. These include the white-tailed deer, gray squirrel, opossum, skunk, raccoon, and fox.
In the spring the woods can be alive with the songs of spring warblers.
Much of the wooded areas are managed in a relatively undisturbed state to provide an environment suitable to a wide range of plants and animals.
Sweet gum, white oak, and black tupelo are the larger trees that can be found. American holly, jackin-the-pulpit, and pink lady slipper also grow here.
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Refuge Management and Objectives…


The refuge management programs are primarily aimed at developing and protecting desirable habitat for waterfowl and other migratory birds, including the endangered bald eagle. The refuge is located at a focal point for waterfowl migrating between their northern breeding grounds and various wintering areas. Large numbers of ducks and geese arrive each fall to either spend the winter or merely stopover on their way southward.
Water levels in refuge impoundments are manipulated to produce desirable emergent and underwater plants for waterfowl. While pools are drawn down, excellent populations of shore and wading birds use the mudflats. Upland agricultural crops are produced on approximately 1,100 acres to provide a supplemental food supply to waterfowl and other migratory birds.
Tidal salt marsh (see more in column on left of this page) is the most valuable wildlife habitat in the State of Delaware. Large portions of the refuge have been maintained in a near pristine state. The marsh, with its intersecting tidal streams and rivers, provides excellent natural habitat for the birds and mammals of the area and also serves as a nursery and breeding area for marine organisms, many of which are of sporting and commercial interest.
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Wildlife Calendar…

See also a month to month analysis at US FISH & WILDLIFE: Seasons of Wildlife


Though wildlife can be seen year round at Bombay Hook, fall and spring offer the best opportunity for observing peak concentrations of migratory birds.
The period from October 1 through November 30 is generally the most interesting to the refuge visitor as this is the season during which waterfowl populations are at their peak. Over 100,000 ducks and geese utilize the refuge at this time.
Spring is another preferred season for the visiting public. March is the second peak for waterfowl as they travel through on their return to northern breeding grounds.
April brings early shorebird migrants and the emergence of reptiles and amphibians from winter hibernation.
Shorebirds are at their highest concentrations during May and June, primarily due to the arrival of horseshoe crabs laying eggs along the bay shore and mud flats. These eggs provide the shorebirds with needed energy to complete their northward migration.
Wading birds such as herons, egrets, and glossy ibis, reach their peak numbers during the summer months.
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Mammals viewed year round…


Mammals can be seen year round, particularly in the early morning and evening hours. These include white-tailed deer, beaver, muskrat, red fox, river otter, woodchuck and opossum.
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Migratory birds: fall & spring…


Fall and spring offer the best opportunity for observing peak concentrations of migratory birds.
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Waterfowl peak: November & December…


Waterfowl populations are at their peak in November and December. More than 150,000 ducks and geese use the refuge at this time.
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March another peak…


March has another peak for waterfowl populations as they travel to their northern breeding grounds.
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April: shorebird migrants…


April brings early shorebird migrants from South America and…
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April: hibernation emergence…


… the emergence of reptiles and amphibians from winter hibernation.
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Refuge water levels…


Water levels in refuge impoundments are manipulated to produce food plants for waterfowl.
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Feeding on mudflats…


When water levels in the pools are lowered, large populations of shore and wading birds feed on the mudflats.
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Upland fields…


Upland fields and forests provide habitat for a variety of migratory birds and other wildlife.
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Tidal salt marsh: marine wildlife nursery…


Tidal salt marsh is some of the most valuable wildlife habitat in Delaware.
The 13,000 acre marsh, with its intersecting tidal streams and rivers, provides excellent natural habitat for birds and mammals and serves as a nursery for marine wildlife.
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Summer months for wading birds…


Wading birds, such as herons, egrets and glossy ibis, reach their peak numbers during the summer months.
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