Find Nature In Delaware

Additional Wildlife of Delaware

To flesh out your understanding of the region’s natural history, here is a breakdown of the specific taxa you can expect to encounter in the First State.

Birds (Avifauna) Delaware is synonymous with the Snow Goose. In winter, the impoundments at Bombay Hook and Prime Hook National Wildlife Refuges host hundreds of thousands of these birds, creating a “blizzard” of white wings and deafening noise when they take flight. The state is also a critical stopover for the Dunlin and other sandpipers. The Prothonotary Warbler, a “swamp warbler” that nests in tree cavities over water, is a star attraction in the cypress swamps of the south, flashing its bright golden plumage against the dark swamp water.

Mammals The conservation flagship for the state is the Delmarva Fox Squirrel. Larger and more lumbering than the common gray squirrel, this silvery-white biological distinct unit was once on the brink of extinction but has been successfully recovered due to habitat management on the peninsula. The coastal marshes are patrolled by the River Otter, an apex aquatic predator here, thriving in the brackish creeks. In the suburban interface, Red Foxes are common, adapting well to the fragmented agricultural landscape.

Insects Delaware is the home of a federally threatened insect found almost nowhere else: the Bethany Beach Firefly. This small beetle is unique because it inhabits the freshwater interdunal swales right along the coast, a habitat that is under intense pressure from development. The state also sees massive migrations of Monarch Butterflies in the fall, which use the goldenrod and seaside groundsel in the dunes as a final fueling station before crossing the Delaware Bay.

Plants The Bald Cypress is the botanical king of the southern swamps, famous for its “knees” (pneumatophores) that protrude from the water to aid in stability and oxygen exchange. Along the coast, the Beach Plum is a hardy shrub that helps stabilize dunes and produces fruit historically used for jams. The state flower is the Peach Blossom, a nod to the state’s agricultural history, but in the wild, the Sweetbay Magnolia is a more defining native species of the coastal plain wetlands.

Fungi The sandy, well-drained soils of the coastal plain are excellent for Gasteromycetes, or “stomach fungi,” such as Earthstars and Puffballs. These fungi rely on raindrops or animal footfalls to compress their spore sacs and puff “smoke” (spores) into the wind. In the hardwood forests of the Piedmont, you can find the Lion’s Mane (Hericium erinaceus), a toothed fungus that grows on dying hardwoods and is highly regarded for both its culinary and potential medicinal properties.

Delaware Biodiversity Profile

Delaware is a state defined by its threshold status; it sits squarely on the biological dividing line between the North and the South. Ecologically, it is almost entirely composed of the Atlantic Coastal Plain, a low-lying, sandy sediment wedge that makes the state the lowest, on average, in the nation. This lack of elevation means the hydrology is dominated by slow-moving rivers and vast networks of marshes. The defining feature is the Delaware Estuary, a funnel-shaped system where the freshwater of the Delaware River mixes with the Atlantic. This mixing zone creates a nutrient trap, fueling massive blooms of plankton that support one of the largest concentrations of shorebirds in the Western Hemisphere.

To the north, a small sliver of the state lies in the Piedmont Plateau. This region, north of the “Fall Line” near Wilmington, offers a stark contrast to the sandy south. Here, the landscape rolls with hills of crystalline rock, supporting tulip poplar and beech forests that feel more like Pennsylvania than the coast. This geological transition zone is critical for biodiversity, as the stream gradients change rapidly, creating diverse micro-habitats for aquatic life before the water slows down into the coastal sluggishness.

In the southern interior, you encounter the Great Cypress Swamp, the northernmost natural stand of Bald Cypress in the United States. This dark, tannin-stained freshwater wetland is a relic of a prehistoric landscape, offering a window into what much of the mid-Atlantic looked like before European drainage efforts. It serves as a critical headwater for the Pocomoke River and provides deep-forest interior habitat that is rare on the heavily agricultural Delmarva Peninsula.

Finally, the Coastal Barrier System along the Atlantic edge is a dynamic, high-energy environment. The dunes of Cape Henlopen and the barrier islands to the south are constantly reshaped by wind and waves. These shifting sands create a specialized “maritime forest” ecosystem behind the dunes, where stunted pines and oaks are pruned by salt spray, creating a twisted, protective canopy for migrating songbirds.