General Wildlife Questions

I have found an injured animal. Can you help it?

CWH cares for wildlife in the wild by providing critical habitat for them. However, we do not have the staff or expertise to care for injured wildlife. If you have an injured wild animal, keep it in a warm, dark place (a box with air holes) and contact a person who is licensed to care for it. A list of these professionals can be found here.


Do geese mate for life?

Canada geese do mate for life. If one mate dies, however, the surviving partner may seek another mate, depending on age.


How long do Bluebirds incubate?

Bluebirds incubate their eggs for about two weeks. The young take their first flight two weeks after they hatch. Bluebirds often produce more than one clutch in a nesting season.


What do Bluebirds eat?

Eastern bluebirds are primarily insect eaters who shift toward berries in colder months when insects are not available. They often migrate short distances to warmer areas to ensure enough food for the winter season. Their diet includes caterpillars, invertebrates, and fruit and nuts. Bluebirds hunt from a perch rather than on the wing and find most of their food on or close to the ground.


How can you tell the difference between a Bluebird nest and a House Sparrow nest?

The bluebird’s nest is constructed of fine, dried grasses and takes up only about a third of the box. The sparrow nest is messy, including feathers and other debris, and can fill the box completely. Bluebird eggs are usually pale blue (although some can be almost white), while sparrow eggs are white with brown speckles.


How long does the female Osprey sit on her nest?

Ospreys incubate their eggs for 38 to 42 days. Females do the majority of the incubating, although males can incubate up to 30% of the time. The young osprey take their flight 50 to 60 days after they hatch. Young osprey require about 2 pounds of fish per day to survive.


When do Ospreys return in the spring?

You can almost set your clock by their arrival—March 17 (St. Patrick’s Day)—although we’ve had sightings a few days and even a week earlier because of our recent mild winters. Adults begin their fall migration as soon as fledglings become independent. Juveniles normally migrate in late August.


On average, how many Wood Ducks fledge from a nest each year?

The average clutch is 12. About 4–6 of these will survive until adulthood. The young usually return to the areas where they fledged to raise their own families.


Why do you want bats around your property?

Bats are beneficial insectivores, a natural predator of many of our pesky night-flying insects. The most common bat found in Maryland, the little brown bat (Myotis lucifugus), can consume up to 600 mosquitoes in just one hour. Bats are feared only to the extent that they are misunderstood. The fear of acquiring rabies from bats is grossly exaggerated. Less than one-half of one percent of bats ever contact rabies, a frequency much lower than that of most mammals.


I’ve been hearing a lot of bad stuff about Mute Swans. Why?

Although elegant to watch as they glide along the water, Mute Swans are indeed harmful to both the Bay and to other waterfowl species native to our region, such as the Tundra Swan and the Black Duck. A non-native, extremely aggressive species, mute swans will drive away Tundras as they compete for food and nesting locations. The Mute Swan also feeds voraciously on our submerged aquatic vegetation (SAV). A cluster of swans can easily devour an entire bed of SAV before moving on to another location.


What do Kestrels eat?

The American Kestrel is a predator that feeds on large insects such as grasshoppers, small mammals such as mice and moles, birds of sparrow size, and, in some cases, reptiles and amphibians.


Delmarva Fox Squirrel, photo courtesy of John White

What does the Delmarva Fox Squirrel look like? Why is it an endangered species?

The Delmarva fox squirrel (Sciurus niger cinereus) is distinguished from the common gray squirrel by its larger size, bushier tail, and steel-gray coloring with a white belly. Delmarva fox squirrels were historically found throughout the entire Delmarva peninsula, southeastern Pennsylvania, and west-central New Jersey. They now occupy less than 10% of their original range. The listing of the Delmarva fox squirrel as an endangered species in 1967 is largely a result of the destruction of mature mixed hardwood forests, their preferred habitat. Human encroachment on the fox squirrel’s territory has also taken its toll. They suffer significant mortality from being run over by automobiles. Fox squirrels are slow moving, which also makes them an easy target for pet dogs and cats.