Unique and Threatened Species of Delaware

How many of our wildlife neighbors have you met?

Atlantic Horseshoe Crab (Limulus polyphemus)

  • Swarm the beaches in late spring during high tides to mate and lay their eggs. They need a gently sloping, sandy intertidal zone for their eggs, and our Delaware Bay beaches are prime habitat!

  • Many migrating sandpipers, including Delaware’s endangered red knots, depend on horseshoe crab eggs to help fuel their long journeys.

  • Are more closely related to spiders than to crabs!

  • Populations fell 90% in the ‘90s-‘00s due to harvesting for bait. They have since only slightly recovered.

  • Threats: over-harvesting, shoreline development, beach erosion

  • How to help: Let your local politicians know that you care about horseshoe crabs! Encourage politicians to continue banning their harvest, to limit beachside development, and to support erosion management.

  • Where they live: Bombay Hook and south along Delaware’s coastline

Bethany Beach Firefly (Photuris bethaniensis)

  • Discovered near the town of Bethany Beach in 1946. It has since been found in other sites in the Delmarva peninsula.

  • Lives in rare freshwater wetlands among sand dunes (“interdunal swales”).

  • Males make a greenish double flash to attract females.

  • The larva has never been observed! Like other firefly larvae, it probably lives in leaf litter and makes its own glow.

  • Status: Delaware State Endangered

  • Threats: coastal development, sea level rise, invasive plants, pesticides

  • How to help: If you own beachfront property, especially near parks, don’t use pesticides, grow native plants, and turn off your property lights at night.

  • Where they live: coastal swales in Cape Henlopen State Park, Fenwick Island State Park, and Delaware Seashore State Park

Eastern Tiger Salamander (Ambystoma tigrinum tigrinum)

  • Eggs are laid in ephemeral (temporary) pools in sandy, semi-forested habitat. The tadpoles are aquatic, and after metamorphosis, adults move onto land.

  • Is a “mole salamander” that spends most of its adult life underground!

  • Is the largest land salamander in North America, growing up to 20 cm long.

  • Status: Delaware State Endangered

  • Threats: loss of ephemeral wetlands, deforestation, pollution, disease

  • How to help: Tell folks, especially landowners, about the importance of ephemeral pools for eastern tiger salamanders and other amphibians!

  • Where I live: western border between New Castle and Kent Counties (around Smyrna and Blackiston); central Sussex Co. (around Georgetown and Harbeson)

Let us know!

Did you reach this page by picking up a free animal magnet? I am distributing three different designs of magnets to Wilmington-area public libraries.

The project creator and illustrator is Megan Paustian.

These magnets were made possible with funding from Skype-A-Scientist.

 

Note: these are all SGCN Tier 1 species from the Focus on Wildlife Action Plan of Delaware, i.e. Delaware’s species of greatest conservation need. “These include the rarest species in the state, species that are highly globally imperiled, and species with regionally important Delaware populations that are also under high threat from climate change.”

 

Learn more

All rare and threatened Delaware species: