January 1-7, 2019 (Week 1 of 52): Winter Raptor Watching is an Exciting Way to Start the New Year

Please note that several of the above photos were taken during a winter raptor study conducted several years ago by the New York State Department of Environmental Conservation. That study was focused on learning more about habitat use and home range size of the short-eared owl (state-listed endangered species) and the northern harrier (state-listed threatened species), and therefore required trapping and tagging of those raptors. Please be aware that trapping wild birds is illegal without proper federal and state permits.

Early January is typically an excellent time of year to actively search for “winter raptors” in the Buffalo-Niagara Region. This group of winter visitant birds-of-prey includes the northern harrier (AKA marsh hawk), rough-legged hawk, snowy owl, short-eared owl, and long-eared owl. While I find it exciting to see any raptor, I especially enjoy watching northern harriers and short-eared owls course back and forth over grassy fields in search of prey, sometimes just above the tops of dried weed and grass stems. Both species often occur in small groups, sometimes consisting of a dozen or more birds in a single field. Short-eared owls are particularly interesting to watch, with their moth-like flight pattern, bark-like vocalizations, and frolicking behavior that occasional includes prey stealing. They are most active near dawn and dusk (crepuscular). It is noteworthy that the long-eared owl, a night-active (nocturnal) species, hunts in a similar manner as the short-eared owl but is much less commonly seen in foraging flight due to darkness.

While winter raptors typically start to arrive in our Region in November, sightings often increase noticeably in January. This may be the result of actual increased numbers of these birds in our Region, or it may simply be the result of increased activity (and thus increased visibility) of these raptors in response to decreased numbers of small mammals and other prey as winter progresses. Deeper snow cover, which provides greater protective cover for meadow voles and other prey, may have the same effect. Under difficult winter conditions, raptors must work harder to catch enough prey to survive. It may take a period of seasonally cold weather with an accumulation of snow before winter raptor sightings increase this winter. Those of us willing to venture out under such conditions may be rewarded by wonderful views of these intriguing birds-of-prey.

Most of the above listed birds-of-prey are found in the Buffalo-Niagara Region during winter months only, typically departing for breeding grounds in late March or early April. While some northern harriers and long-eared owls breed in our Region, most nest near open lands within the boreal forest zone of Canada. Short-eared owls breed primarily in open muskeg areas along the northern edge of the boreal forest zone and across the tundra zone of Canada. Rough-legged hawks and snowy owls breed primarily in the Arctic tundra and come south only during winter months.

Winter raptors are exceptional “mousers,” well adapted for catching small mammals and birds. All three species of owls listed above, as well as the northern harrier, have facial disks that reflect and concentrate sound waves toward the ears (much like commercially available parabolic listening devices). The owls also have asymmetrically located ear openings that allow the owls to locate sound sources by triangulation. These hearing adaptations greatly assist in detecting prey by sound. That is an important skill when hunting meadow voles. This field mouse creates extensive networks of runways beneath grassy cover, and maintains them beneath snow, where they stay very well concealed from sight. However, the vole’s high-pitched vocalizations and other sounds are detected by owls and the northern harrier, to the extent that these raptors can catch voles by sound alone (sometimes under a foot of powdery snow).

Another amazing ability of the three owl species is night vision. Several eye adaptions allow owls to see well in extremely low light levels. Those adaptations include large eye size relative to body size, large pupil opening for maximizing the amount of available light entering the eye, large lens and cornea to enhance light gathering, and a retina layer that is packed with rods – light sensing cells. These night vision adaptations greatly assist owls in locating and capturing prey after dark.

For folks interested in finding winter raptors in the Buffalo-Niagara Region, here are a few tips. Time of day is important. Day-active (diurnal) species such as the northern harrier, rough-legged hawk, and snowy owl can be found most any time between sunrise and sunset. However, late afternoon is typically the best time to find the crepuscular short-eared owl, usually from about a half hour before to a half hour after sunset. Focusing searches in areas of suitable habitat is also key. Winter raptors are typically found in broad, open, tundra-like areas with extensive grassland habitat. These birds-of-prey often require 100 acres or more of quality grassland habitat such as fallow farm fields, hay fields with relatively long grass (versus short-mowed), pastureland, and airports. Such areas typically provide the highest densities of meadow voles and similar prey animals.

Scan large grassy fields with binoculars to locate raptors that are perched or in flight. The rough-legged hawk and especially the snowy owl are most often seen perched on fence posts and other low objects, utility poles, treetops, etc. In contrast, the northern harrier, short-eared owl, and long-eared owl frequently hunt on-the-wing, coursing back and forth low over grassy fields. Rough-legged hawks also hunt in flight but typically from considerably higher heights and often by hovering in place. Short-eared owls occasionally perch on fence posts and utility poles, but most of their foraging time is spent in flight. Finally, frequently check eBird, Genesee Birds, and Dial-a-Bird (see the “Resources” tab on this web page for more details) for reports of winter raptors.

Identification of some raptors may be difficult for beginner birders. The most challenging of the five species covered here is the rough-legged hawk. This species is similar in size and sometimes in color pattern to the red-tailed hawk, a much more common buteo in our Region. Key field marks differentiating rough-legged from red-tailed hawks include the white rump patch and dark wrist marks (seen in flight) of the rough-legged hawk and the rusty red upper tail color (adults only) and white un-streaked chest of the red-tailed hawk. To add to the challenge, two color morphs of rough-legged hawks (light and dark) occur in our Region. Northern harriers also vary in color. Adult females are dark brown with streaked chest and belly, juveniles are dark brown with cinnamon-colored chest and belly, and adult males are a striking combination of gray upperparts, white underparts, and black wing tips. All have a large white rump patch. Consult field guides as necessary to validate species identifications.

When searching for winter raptors and observing birds you’ve discovered, be sure to be respectful of private property rights by requesting landowner permission before entering private land. Keep in mind that these birds can often be observed well from public roads. However, that needs to be done safely and respectfully by parking cars on road shoulders completely out of travel lanes (which simply may not be possible on some roads), staying off roads while observing birds on foot, and paying close attention to traffic when crossing roads. Of course, be respectful of the birds by not approaching too closely and by avoiding any other behavior that may be disruptive. Disturbing these birds causes them to waste vital energy reserves at this crucial period of survival. More details about safe and respectful birding are available at https://www.dec.ny.gov/press/112637.html.

Below are highlights of what you can expect to find outdoors in the Buffalo-Niagara Region this week. Those in bold/italics are new or substantially revised highlights to watch for this week. Check out the list of 300 publicly accessible sites at https://bnnatureblog.com/nature-sites/site-lists/alphabetical-list/ to find areas to explore in your neighborhood and throughout the Buffalo-Niagara Region.

Average Sunrise/Sunset (Day Length):

  • 7:47 AM/4:54 PM EST (9 Hours, 7 Minutes)
  • 0 Hours, 6 minutes of daylight longer than at Winter Solstice

Typical Weather:

  • Normal High Temperature: 31.9° F  Normal Low Temperature: 19.5° F

Lake, Pond, Stream & Wetland Conditions:

  • The Lake Erie water temperature off Buffalo cooled to 38°F and the Lake Ontario water temperature off Greece (Monroe County) cooled to 39°F as of January 2, 2019.
  • Water levels in most interior wetlands and vernal pools are close to seasonal highs after a long period of normal or better precipitation and greatly reduced evapotranspiration rates.
  • Similarly, water levels in many ponds are now close to seasonal highs.

Fungi:

  • The hard frost/freeze we experienced over the past few weeks extinguished most fungal fruiting bodies. The fungal “roots” (mycelium network) will survive the winter and produce new fruiting bodies during the appropriate season next year. Interestingly, fruiting bodies of some species of fungi (e.g., oyster mushrooms) remain viable during the winter and may disseminate spores during warm periods or in early spring.

Ferns and Grasses/Sedges/Rushes:

  • The hard frost/freeze we experienced over the past few weeks killed remnant grass, sedge, and rush stems (thus known as a killing frost). The roots of these perennial plants will survive and sprout next spring.

Wildflowers:

  • The hard frost/freeze we experienced over the past few weeks killed remnant wildflower stems (thus known as a killing frost). Roots and rhizomes of perennial wildflowers will survive and sprout next spring. Seeds of annual wildflowers will do the same.

Trees and Shrubs:

  • Many American beech leaves remain clinging to limbs but have now changed to brown. Some beech trees will hold their leaves the rest of the winter.
  • Several native shrubs and vines continue to provide fruit (soft mast) that is an important winter food source for a variety of birds and mammals: winterberry, cranberry viburnum, staghorn sumac, and swamp rose.
  • In addition, one non-native species, multiflora rose, provides fruit consumed by wildlife.

Insects & Other Invertebrates:

  • The hard frost/freeze we experienced over the past few weeks killed most adult insects and other invertebrates that have not migrated or entered hibernation. The vast majority of insect species in our Region over-winter as eggs or larvae/nymphs, although some species over-winter as adults.

Fish:

  • Many species of fish have moved into shallower areas and are feeding more heavily as water temperatures have cooled, including muskellunge, walleye, smallmouth bass and schools of yellow perch.
  • Steelhead continue to occur in Great Lakes tributaries and the Lower Niagara River at this time. Spawning does not occur until late winter and early spring. Steelhead are an anadromous form of rainbow trout that spawn in streams but live most of their lives in Lakes Erie and Ontario. All forms of rainbow trout are native to Pacific coast watersheds.
  • Brown trout continue to occur in Great Lakes tributaries and the Lower Niagara River. Spawning typically occurs from late October to December in these tributaries. Brown trout were introduced from Europe.

Amphibians & Reptiles:

  • With the onset of winter weather, essentially all amphibians and reptiles are now hibernating.

Water & Shore Birds, Gulls & Terns:

  • The annual buildup of “sea ducks” and similar waterbirds that over-winter in the Great Lakes and Niagara River continues with additional arrivals of greater scaup, lesser scaup, canvasback, redhead, common goldeneye, bufflehead, white-winged scoter, surf scoter, black scoter, long-tailed duck, common merganser, and red-breasted merganser.
  • Watch for winter resident tundra swans congregating in open waters along the upper Niagara River (especially off Beaver Island, Buckhorn, and Niagara Falls State Parks).
  • This continues to be a good time to look for purple sandpipers feeding in rocky habitats above Niagara Falls.
  • Bonaparte’s gull numbers will remain relatively high in the region this week, using the Niagara River as a significant stop-over feeding area along their migration route south. This species typically reaches its peak fall numbers in the region in November and December when thousands may be observed along the Niagara River.
  • This is an excellent time to watch for rare species of gulls such as Franklin’s, little, black-headed, California, Iceland, Thayer’s, lesser black-backed, Glaucous, Sabine’s, and black-legged kittiwake among more common species such as recent arrivals of Bonaparte’s and greater black-backed gulls. Such rarities add to the remarkable diversity of gull species – 19 species total – that have been observed along the Niagara River and bordering Great Lakes. The peak time is typically between mid-November and mid-January.

Birds of Prey:

  • Bald eagles can be found along the upper and lower Niagara River where good numbers will over-winter.
  • Winter resident raptors will continue to arrive in the region, especially in areas with extensive open grassland habitat, including northern harriers, rough-legged hawks, snowy owls, short-eared owls, and long-eared owls.
  • Snowy owls are frequently found along Great Lakes shorelines, such as the Buffalo waterfront, where they feed on ducks and other waterbirds.
  • Great horned owls have started to pair-up, form pair bonds, and establish nesting territories. Listen for their vocalizations, especially near sunset and sunrise, including duets consisting of a female and male singing nearly in unison (with male calls noticeably lower in pitch than those of the female).

Upland Game Birds:

  • Watch for wild turkey flocks in farm fields, along forest edges, and near bird feeders.

Songbirds:

  • Watch bird feeders for the following songbird species that are part of this year’s “winter finch” irruption: purple finch, red crossbill, white-winged crossbill, common redpoll, hoary redpoll, pine siskin, evening grosbeak, and red-breasted nuthatch. Nyjer (AKA thistle) and black oil sunflower are the best seeds for attracting these species.
  • Bird feeders are also excellent locations to watch for arrivals of more typical migrant and over-wintering feeder birds such as dark-eyed junco, white-throated sparrow, song sparrow, and American tree sparrow.   Place seed such as white millet in ground feeders or directly on the ground to attract many of these migrants.
  • Bird feeders will continue to be active with year-round resident birds such as mourning dove, downy woodpecker, hairy woodpecker, red-bellied woodpecker, black-capped chickadee, tufted titmouse, white-breasted nuthatch, blue jay, northern cardinal, house finch, and American goldfinch.
  • Good tips for feeding birds are available from the Cornell Lab of Ornithology, online at http://www.birds.cornell.edu/AllAboutBirds/notes/BirdNote01_WinterFeeding.pdf
  • If you don’t have a feeder of your own, consider visiting a local nature center (see the 2nd to last column in the tables of nature viewing sites found under the “B-N Region & Sites” tab on this web page).
  • The northern shrike, a predatory passerine that breeds in Canada and Alaska, will continue to occur in the Region. Watch for them on prominent perches overlooking open and brushy habitats.
  • Most eastern bluebirds, American robins, eastern meadowlarks, red-winged blackbirds, common grackles, brown-headed cowbirds, and summer resident sparrows have now left the Region for southern climes.
  • While most American robins have migrated south, small to medium sized flocks may still be encountered.
  • Small flocks of horned larks are being joined in open farmland and other tundra-like habitats by snow buntings and Lapland longspurs. Many will over-winter in our region.
  • To stay abreast of bird sightings in the region, consult eBird, Genesee Birds, and Dial-a-Bird (see the “Resources” tab on this web page for more details).

Mammals:

  • Resident species of cave bats (big brown, little brown, and eastern pipistrelle [tri-colored] bats) have entered hibernation. Most woodchucks have also started their winter hibernation. Two other species of true hibernators, meadow jumping mouse and woodland jumping mouse, have also begun hibernation.
  • Most eastern chipmunks are in a state of torpor. In this condition, which is not a true form of hibernation, chipmunks sleep but arouse frequently to feed on hoarded food. They may forage aboveground during mild weather.
  • Gray squirrels and southern flying squirrels continue to actively forage for cached acorns and other available food. Similarly, red squirrels feed from middens of pine and spruce cones.
  • Watch bird feeders after dark for nocturnal visits by southern flying squirrels.
  • White-footed mice and deer mice prepare for winter by building nests in woodpecker holes, bird houses, and squirrel leaf-nests. Some rehab old bird nests by adding a roof and insulation. These mice often cross paths with homeowners this time of year as they seek shelter in sheds, garages, and houses – along with non-native house mice.
  • Beavers continue to feed on cut branches they cached in shallow water near their lodges during the fall.
  • Ermine (AKA short-tailed weasel) have molted from brown to white pelage for winter months.
  • Black bears, an uncommon species in the Buffalo-Niagara Region but increasingly common to our south, are in carnivorous lethargy. In this state, which is not a true form of hibernation, a bear’s heart rate is significantly lowered but body temperature falls only about 10°F (substantially smaller drop than for true hibernators).

Be sure to find an opportunity to get outside this week to discover signs of the season.

Chuck Rosenburg

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