Endangered bird species found at Weir Farm

May 20 marked the 11th annual Endangered Species Day, which falls on the third Friday in May and recognizes the importance of protecting endangered species and their environments.

A number of endangered species can be found in Fairfield County, according to the Connecticut Department of Energy & Environmental Protection (DEEP), including more than 40 plants and about 30 mammals, invertebrates, fish, birds, reptiles and amphibians as of September 2015.

According to the U.S. National Park Services Integrated Resource Management Applications (IRMA) Portal database, at least two endangered species — the sharp-shinned hawk (Accipiter striatus) and the barn owl (Tytpo alba) — are reportedly "present" at the Weir Farm National Historic Site, 735 Nod Hill Road.

Sharp-shinned hawks

According to the DEEP, sharp-shinned hawks are slender and long-bodied — measuring 10-14 inches in length — with short, rounded wings spanning 20-27 inches, and long, narrow tails.

Adult sharp-shinned hawks have dark, blue-gray backs and rusty-barred breasts, while immature hawks have more brown, with streaking on their underparts.

Male and females are similar in appearance, but females are about one-third larger. Females weigh between six and eight ounces, while males weigh between three and four ounces.

Sharp-shinned hawks live in large, remote, young forests and prey on small birds, as well as mice, shrew, bats, frogs and insects.

These birds are found throughout most of North America. In the fall, large numbers of them pass through southern New England as they migrate to the southeastern United States and Central America for the winter.

Sharp-shinned hawks are common migrants from the end of the summer until early November in Connecticut, according to the DEEP, although some of them stay in the state during the winter and frequently prey on smaller birds visiting nearby bird feeders.

Except for migration counts, reliable sharp-shinned hawk population data for Connecticut are scarce, according to the DEEP. Due to its small breeding population in the state, the sharp-shinned is listed as a threatened species in Connecticut.

While the IRMA database lists the species as "present" at Weir Farm, their abundance is listed as "uncommon."

Click here to learn more about the sharp-shinned hawk.

Barn owl

The barn owl, on the other hand, is more common. In fact, the species is found on every continent except Antarctica, according to the DEEP.

Barn owls have white, heart-shaped facial disks, no ear tufts and long legs, and appear white from below and golden-brown from above, with black specks all over. They are also referred to as golden owls, white owls, monkey-faced owls and white-breasted barn owls.

These birds live in open areas like grassy fields, old fields, wet meadows and wetland edges, around farms and rural towns, according to the DEEP, and their daytime roost is usually an evergreen tree, belfry or barn.

According to the DEEP, male and female barn owls can be distinguished by differences in coloration and weight. Males usually have whiter breasts with fewer and smaller dark specks, while females are typically heavier and have more and larger dark specks.

Male barn owls are 13-15 inches long, weigh 14-19 ounces and have wingspans of 41-45 inches, and females are 14-20 inches long, weigh 17-25 ounces and have wingspans of 43-47 inches.

Newborn barn owl chicks are covered with down, but acquire adult-like plumage 8-10 weeks after they're born.

Barn owls are considered "partly migratory" in the northeastern United States, according to the DEEP, "although many individuals remain there throughout the winter" and "band recoveries indicate that some northeastern barn owls winter in Texas and the southeastern part of the country."

Barn owls occur in low numbers in Connecticut, "probably because grasslands and farmlands are declining," according to the DEEP, and Connecticut's historic barn owl population status is unknown. Similarly, the IRMA database lists barn owl abundance at Weir Farm as "unknown."

Click here to learn more about the barn owl.