Flora of the Refuge

Five Habitats

The tiny Heinz Refuge, located on the outskirts of the city of Philadelphia, has within its boundaries five distinct habitats serving the needs of a rich diversity of wildlife. Indeed, the refuge is often referred to as a "migratory motel," providing food and shelter for migrating birds and a year-round home for many other birds, animals, amphibians, insects, and fish.

The woodlands, locally known as "Warbler's Woods," are found on the eastern edge of the refuge. Poplar, cherry, maple, white pine, and hackberry trees are favorite resting and feeding spots for hundreds of warblers as they stop by for a visit during spring and fall migration.

Nearby oldfields and wildflower meadows provide favorite spots for ground-nesting birds, along with plentiful and varied food for birds, many small animals, and butterflies. Oldfields are also a favored burrowing spot for turtles in need of a good place to hibernate in winter. Typical flora found in these sites include smartweed, knotweed, varied grasses, goldenrod, aster, milkweed, joe-pye weed, blackberry brambles, and button bush, just to name a few. A vernal pond also graces this area, hosting spring peepers and frogs, and is frequently used by nesting waterfowl and their young.

West of the oldfields is the refuge's impoundment. Roughly 145 acres in size, the impoundment is flooded in the late spring and drained in late summer to provide a plentiful source of food for migrating waterfowl. In the summer months, Tree Swallows nest in boxes in the impoundment and Wood Ducks nest in boxes in isolated little bays found in its far edges. An island on the far side of the impoundment has alternately held a heron rookery and nesting eagles. Plants found in the impoundment include duckweed, spatterdock, pickerel weed, arrowhead, and loosestrife (an invasive).

The last 4.5 mile segment of Darby Creek passes through the refuge on the way to its confluence with the Delaware River. The creek is tidal with an average variation between high and low tides of five feet. Creek banks contain willow, alder, and sumac trees, coupled with many small shrubs, and a host of herbaceous plants. In summer, snags in the creek are great roosting spots for herons and egrets as they eye the fast-moving waters looking for a meal. Carp, catfish, mummichogs, eels, and clams call the creek home and in recent years, shad have come upstream to spawn.

Refuge marshes are great food producers. Wading birds flock to the mudflats searching for a meal. Ducks, egrets, and herons are frequent visitors. Muskrats find plenty of building material for their lodges, and marsh nutria flow into the Delaware River as it winds its way to the Delaware Bay and the ocean. The marshes also recharge the groundwater and absorb floodwaters; their plants absorb pollutants and in exchange release oxygen to both the water and the air.