Over the next few days, there will be Halloween celebrations happening around the island with lots of spooky decorations that often include wildlife themes. At this time of year, bats and owls are portrayed as animals to be frightened of – likely because they are creatures of the night, when humans are more vulnerable. In particular, owls are considered by many cultures to be unlucky or even evil omens associated with witchcraft and black magic.

This Halloween, let’s take a moment to learn about the owl species that inhabit our island….and instead celebrate them as fascinating and beautiful components of Nantucket’s fauna!

Barn Owl (photo credit: eBird, Sharif Uddin)

Barn Owl (Tyto alba)

As the name implies, barn owls often inhabit old barns and other human-constructed structures. These medium-sized owls have tawny-gray feathers on their back and wings and creamy-white feathers on their face, breast and legs. Owls in general are known for their distinctive facial disks, which function much like a satellite dish to effectively capture sound so that they can locate their prey when hunting. The facial disk of a Barn owl is heart shaped and white, in sharp contrast to its dark eyes.

Barn owls are listed as a “Species of Special Concern” under the Massachusetts Endangered Species Act. This means that their populations have suffered declines that could threaten the species if allowed to continue unchecked. They are closely associated with open, grassy habitats where they hunt for their preferred prey – small mammals such as the meadow vole (Microtus pennsylvanicus). Because much of Massachusetts has become re-forested over the last century due to abandonment of farming and other forms of agriculture, barns owls are now relatively rare, limited to the Cape, Islands and a few isolated locations elsewhere in the Commonwealth.

This species prefers a climate with relatively mild temperatures. They were not historically common on Nantucket, but their range has recently expanded in response to warmer winters due to climate change impacts. Barn owls began breeding on the island in 1968, but the species has experienced several population crashes during harsh winters, most recently on 2005. Since then, populations across the island have been steadily increasing, as documented by researchers at the Maria Mitchell Association. Their recovery has been assisted by the construction of nest boxes at numerous locations across the island.

Northern Saw-whet Owl (photo credit: eBird, Kenny Miller)

Northern Saw-whet Owl (Aegolius acadicus)

Northern saw-whet owls have mottled brown plumage, with small white spots on their head and bright yellow eyes. This small species (about the size of an American robin) is one of the more common owls on the island. Unlike barn owls, they are closely affiliated with forested habitats and can be found on Nantucket in the State Forest and other pitch pine forests across the island. Like barn owls, they are cavity nesters, using chambers previously excavated by woodpeckers in dead trees and occasionally nest boxes.

Saw-whet owls are voracious predators, sometimes referred to as “cute killing machines.” Their preferred prey is small mammals, particularly deer mice (Peromyscus leucopus) that prefer forested habitats, but they may also take small birds and insects. Saw-whet owls hunt primarily at night by perching along the forest edge and diving to catch prey when it is detected.

During the daytime, they roost in dense trees, usually close to the trunk, and are very rarely seen. However, their loud, distinctive “too-too-too” call can be heard is areas where they occur between late winter and early summer. The interesting common name of this species is believed to be derived from the similarity of their call to that of a saw being sharpened on a whetting stone.

Long-eared Owl (photo credit: eBird © Steven S. Ross)

Long-eared Owl (Asio otus)

Long-eared owls are also listed as a “Species of Special Concern” in Massachusetts. According to MassWildlife, there have been fewer than 10 breeding occurrences documented in the past 35 years in Worcester, Essex, Plymouth, Barnstable, Dukes and Nantucket counties. Although this may be, in part, due to their secretive nature, long-eared owls are believed to be a rare breeding species here. While they are more common across Canada and northern New England and New York, Massachusetts is at the southern end of their range.

These medium-sized owls get their name from the “ear” tufts along the top of their heads, which are not actually ears, but tufts of feathers that disrupt the outline of their silhouette to make them less visible. Their streaked plumage is a soft grayish brown, with a buff-colored facial disk, yellow eyes, and darker feathers on either side of the bill. Long-eared owls resemble the closely related short-eared owl, which once also nested on Nantucket but has sadly been extirpated here since the mid 1990’s.

Long-eared owls prefer dense, coniferous forest habitat for nesting that is adjacent to open areas for hunting small mammals and songbirds. They are strictly nocturnal, very secretive, and rarely seen or heard; their vocalizations consist of a soft, one-pitched “hoot.” They do not tend to build nests of their own, but instead utilize previously built nests once occupied by crows, squirrels, and other birds of prey. During the winter, they have been known to share communal roosting sites in dense conifers. These sites may be located by observing accumulated droppings and owl “pellets” (regurgitated prey remains) underneath trees, especially if there is snow cover.

Snowy Owl (photo credit: eBird, Kevin Vande Vusse)

Snowy Owl (Bubo scandiacus)

Although the previously described species are all known to breed on Nantucket, the snowy owl is only observed here during the winter and early spring, and not every year. During the non-breeding season, snowy owls will remain on their Arctic breeding grounds if there is sufficient prey present, but will travel southward in years when prey is scarce. Their search for winter food often brings them to Nantucket during such “irruption” years, such as occurred in 2013, where they seek out treeless, wide-open landscapes such as coastal dunes, beaches, and low grasslands that mimic the tundra habitats where they breed up north.

These beautiful birds are actually voracious predators, feeding on small mammals, larger shorebirds, seabirds and waterfowl. Unlike many other owls, they are diurnal- meaning that they often hunt during daylight hours. They have brilliant yellow eyes and rounded heads that rarely show ear tufts. Because they are adapted to the arctic, their legs are fully feathered. They are one of the largest and heaviest species of owl, ranging from pure white (adult males) to white with black “salt and pepper” speckling (females and immature birds). Harry Potter’s owl, Hedwig, propelled this species to stardom during the popular movie series. However, the owl that portrayed the female Hedwig in the movie was pure white, and therefore most likely a male owl.

Happy Halloween, everyone!!

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