4 Endangered Animals Fighting For Survival In Delaware

From the sandy beaches of its eastern Atlantic coastline to the Appalachian foothills in the north, Delaware’s diverse ecosystems are home to a range of fascinating animals. However, not all of the state’s species are thriving. Over 80 insects, birds, mammals, fish, and reptiles are currently on Delaware’s endangered species list.

This article delves into the state's most endangered animals, which are fighting for their survival amid challenges such as habitat loss, pollution, and disease. From a majestic falcon to a tiny bog-dwelling reptile, these vulnerable creatures contribute much to their native ecosystems and are at the heart of several key conservation projects aiming to ensure their survival for years to come.

American Kestrel (Falco sparverius)

Found all over America, in meadows, grasslands, fields, and deserts, the Kestrel is an opportunistic falcon that preys on small rodents, reptiles, and insects. It perches or hovers, waiting patiently for movement, before swooping down to grab its meal. The American Kestrel is a small falcon, measuring about 9-12 inches (23-30 cm) long with a wingspan of 20-24 inches (51-61 cm). Males are slate-blue and rusty with black markings, while females are mostly rusty-brown with dark barring.

Once a popular sight in the skies over Delaware, the American Kestrel was placed on Delaware’s endangered species list in 2013 following a steady decline. Populations of the bird of prey have dropped more than 93% over the last 50 years in the mid-Atlantic region. Factors contributing to its decline include loss of nesting sites, insecticide and rodenticide use, and a drop in insect populations that disrupts the bird’s food supply.

To tackle some of these issues, Delaware’s Department of Natural Resources and Environmental Control is teaming up with the Delaware Kestrel Partnership to study and protect the state’s kestrels. Projects include adding more than 70 nest boxes to areas such as meadows, fields, and grasslands, as well as the Leg Band Program, which enables researchers to track adults and their chicks. In 2024, conservationists fitted 14 birds with radio tags so they could monitor their movements year-round. These efforts are seeing results, as in the same year, a total of 40 eggs were laid at the new nesting boxes, the program’s highest yield so far.

Bog Turtle (Glyptemys muhlenbergii)

At just 3.5-4.5 inches (9-11 cm) long, the tiny Bog Turtle is America’s smallest turtle. Native to the Eastern United States, the miniature reptile lives in shallow wetlands where it can submerge itself in mud or catch some sun by the rushes. Easily identifiable thanks to their small size, you can also spot a Bog Turtle from the distinctive yellow-orange patches on its head.

Bog Turtles feed on plants, seeds, berries, earthworms, slugs, and insects. They typically live up to 50 years, but are endangered in Delaware primarily due to habitat loss. As of 2025, there are just two known populations in the state and around 20 adult Bog Turtles in total. In 2022, the state government began monitoring the turtles, protecting their existing habitats and controlling predators in those areas. A hatching program at Brandywine Zoo is collecting eggs to hatch in captivity with the eventual aim of reintroducing the species to new marshy areas. Delaware hopes to have five sites, supporting 40 turtles each, within the next 20 years.

Little Brown Bat (Myotis lucifugus)

From a tiny turtle to a bite-sized bat, the Little Brown Bat is one of nine bat species in Delaware. Adults are 3-4 inches (7-10 cm) long with a wingspan of 8-11 inches (20-28 cm) and weigh less than half an ounce (about 8 grams). They have glossy brown fur and darker wings, giving them their name. It’s also one of the rarest thanks to White-Nose Syndrome. This devastating disease, caused by a fungal pathogen, was first confirmed in the United States in 2006 and has killed around six million bats.

The Little Brown Bat was hard hit by the disease and was added to Delaware's endangered species list in 2014. It is now one of the rarest of Delaware’s nine bat species. The bat’s preferred habitat is secluded caves where it can roost undisturbed, and it has been found to hibernate in cave-like structures in Fort Delaware and Fort Dupont State Parks.

The Delaware Bat Program monitors bat populations and prevents the spread of White-Nose Syndrome through research and public awareness. Volunteers ‘adopt’ colonies, counting them and notifying researchers of any changes. The program also encourages groups to build bat boxes and uses detectors to record bat calls in areas where they gather or migrate so researchers can better track their patterns. Conservationists hope this mix of citizen science and research-backed intervention will help reduce White-Nose Syndrome and help populations recover.

Delmarva Fox Squirrel (Sciurus niger cinereus)

In 1967, the Delmarva Fox Squirrel was placed on the federal endangered species list after extensive logging destroyed much of its habitat across the United States. While populations have since recovered, the small mammal remains on the endangered list in Delaware, where it is still struggling. The Delmarva Fox Squirrel is about 10-15 inches (25-38 cm) long with a bushy tail that adds another 10-13 inches (25-33 cm). They are larger than gray squirrels, with a silvery-gray coat and white underside that makes them stand out in the forest.

The peninsula's remote woodlands are its only habitat in Delaware, but scientists are hoping to change that with an ambitious conservation plan that involves shipping squirrels in from Maryland, where populations are stable. These efforts began in 2020-2021 when 30 Delmarva fox squirrels were moved from Maryland to the Assawoman State Wildlife Area.

Since then, Maryland squirrels have been moved to two other sites — Redden State Forest and Trap Pond State Park — and some were fitted with collars so scientists could gather data on how they were settling in. In total, 123 squirrels were rehomed and were split fairly evenly into male and female to encourage breeding pairs. The program has been successful so far, with reproduction at all three sites. Some squirrels even felt comfortable enough to extend their habitat, roaming into nearby areas. One homesick rodent even made it all the way back to Maryland. Going forward, conservationists will keep a close eye on the new residents to ensure they are thriving in their new homes.

Delaware’s Endangered Animals

Delaware may be the second smallest state in the country, but it boasts many unique and interesting animal species. The state is also very proactive in protecting its wildlife, prioritizing conservation initiatives for its most vulnerable.

These programs often rely on public participation, with citizen scientists providing researchers with invaluable information about population sizes, habitat distribution, and behavior. If you’re visiting Delaware’s many beautiful, scenic, and rural areas, you could be a part of these efforts, too. Whether you’re hiking, swimming, boating, or biking, keep an eye out for unusual critters. If you spot any of the endangered species above, notify the DNREC Division of Fish and Wildlife and don’t disturb them. If it’s safe to do so, take a photo, as that will help authorities verify the sighting. And don’t forget to enjoy the moment — seeing these wonderful creatures in the wild is a one-of-a-kind vacation memory.