January 22-28, 2019 (Week 4 of 52): Most of Our Summer Birds Survive Winter Through Mass Migration

The vast majority of our summer birds survive winter by escaping the Buffalo-Niagara Region, migrating to warmer climes well to the south. The longest distance migrants fly 1,500 – 3,000 miles or more to spend winters in the West Indies, Mexico, Central America, and/or South America. These birds are often referred to as neotropical migrants. Shorter distance migrants travel more modest distances of 300 – 1,500 miles to over-winter in the southeastern United States. Migration demands a large investment of energy and poses substantial risks to migrants such as predation, competition with other animals that already occupy wintering areas, exhaustion and death from drowning while crossing large waterbodies, and collisions with buildings and other objects. Regardless, migration has evolved to be the most common strategy for winter survival of birds that nest in the Buffalo-Niagara Region.

Adult and young-of-the-year neotropical migrant songbirds typically depart the Buffalo-Niagara Region in late August and September, in anticipation of the upcoming scarcity of insect prey. This group of birds includes hummingbirds, flycatchers, vireos, thrushes, about 20 species of warblers, and several miscellaneous other species. Most reach their wintering destinations by late September and October, clad in relatively drab plumage (compared to their colorful breeding plumage). Ruby-throated hummingbirds, the smallest bird in our Region, trek as far south as Costa Rica and Panama often including a flight across the Gulf of Mexico of 600 miles or more. Wood thrushes also over-winter in that area, but the veery (another species of thrush) migrates considerably further south – to Brazil and beyond. One of the relatively common warblers that nests in our region, the American redstart, is currently residing in the West Indies and from southern Mexico south to Ecuador and Guyana. The Blackburnian warbler travels even further south, with some reaching Venezuela, Colombia, and Peru. Our beloved Baltimore orioles over-winter primarily from southern Mexico to Colombia. Many scarlet tanagers travel well into South America, as far south as Peru and Bolivia. Still, bobolinks take the prize for furthest songbird migration with some traveling 4,000 miles to winter as far south as Paraguay and Argentina. It is noteworthy that neotropical migrant birds spend more months in their wintering areas than in their breeding areas (such as our Region), so it is irrational to claim them as “our” birds.

Shorter-distance migrants, most of which are destined for southeastern United States, typically linger in our Region well into fall. This group includes many of the ducks and rails that nest in our area, as well as some shorebirds and hawks. While many of our nesting songbirds are neotropical migrants, a handful of species winter within the continental United States, including northern flicker, eastern phoebe, tree swallow, eastern bluebird, American robin, eastern towhee, song sparrow, and red-winged blackbird.   Most of the above-listed species are currently spending winter months in areas from Arkansas to Virginia and south to the Gulf of Mexico.

While most of our summer birds migrate south for winter, a fair number remain in the Region as year-round residents, migrating little if any. Examples include wild turkey, red-tailed hawk (although some individuals migrate), mourning dove, eastern screech owl, downy woodpecker, black-capped chickadee, and northern cardinal. These year-round residents are joined by winter visitants that include several species of ducks, tundra swans, over a dozen species of gulls, several winter raptor species, northern shrikes, horned larks, snow buntings, red-breasted nuthatches, American tree sparrows, and dark-eyed juncos. In some years, large numbers of “winter finches” and other irruptive species (e.g., pine siskins, common redpolls, evening grosbeaks, white-winged and red crossbills) join the mix.

These over-wintering birds exhibit a variety of adaptations that help them survive food scarcity and cold temperatures during western New York winters. They must produce enough metabolic heat from food or fat reserves to offset heat and energy lost to their cold surroundings. That is particularly challenging for small-bodied songbirds that are especially prone to heat loss. Fortunately, feathers provide these and other birds with an excellent layer of insulation. Species that over-winter in northern latitudes, such as the black-capped chickadee and American tree sparrow, may add up to 50 percent more feather mass during their fall molt. Birds also fluff out their feathers when cold, which bolsters their insulating value by trapping air in tiny pockets near the skin. The legs of snowy owls and rough-legged hawks are feathered all the way down to their talons to provide extra insulation. Some wintering birds will draw up one leg beneath their feathers when perched to reduce exposure. In addition, some species add considerable body fat before winter sets in by feeding heavily when food is abundant during fall. That extra layer of fat affords additional insulation and provides essential energy reserves to help maintain body temperature.

On the surface, one might think that ducks and other waterbirds which spend much of the winter exposed to near-freezing water temperatures would be at severe risk of frostbite to their exposed legs and feet, and of losing excessive amounts of body heat to the cold water. Fortunately, these birds suffer no ill effect as they are well adapted to those harsh conditions. The exposed parts of their legs, from the knees down, consist mostly of resilient bones and tendons protected by thick scales. Furthermore, these birds have an outstanding physiologic adaptation that helps to minimize heat loss through legs and feet. They utilize countercurrent blood flow associated with dense networks of veins that are in close contact with arteries going out to the legs. Warm blood going out to the legs heats cold blood coming in from the legs and returning to the animal’s core. Cold blood coming in from the legs cools warm blood going out to the legs. In this way, legs and feet are constantly cold but warm enough to keep tissues alive. Moreover, less body heat is lost by reducing the temperature gradient between blood in the veins and cold water temperatures.

One the most remarkable winter bird survival adaptations is the ability of black-capped chickadees and a few other species to lower their body temperatures at night by up to 20° F in a controlled state of torpor, sometimes called regulated hypothermia. In that state, they become temporarily unconscious but recoup a considerable energy savings. At dawn, chickadees raise their body temperature back to normal and regain consciousness so that they can feed. Other songbird species, such as the American goldfinch, shiver constantly as they sleep to generate body warmth. While effective at generating body heat, that approach uses considerably more precious energy.

The most common adaptations exhibited by over-wintering birds are behavioral changes focused on improving feeding efficiently and conserving energy. Some of these behavioral adjustments start in autumn, with most birds feeding actively during that period of abundant food resources to build up fat reserves. In addition, some species cache food for consumption during lean winter months. For example, white-breasted nuthatches, red-headed woodpeckers, and blue jays cache seeds and other foods in crevices and under loose bark. Great horned owls cache unfinished prey for later consumption. Once cold weather sets in, the most important thing for a bird to do is to consume enough food during the day to maintain fat reserves. As soon as dawn breaks, birds begin searching for energy-rich foods such as fruits and seeds. Some birds flock together to optimize their search efforts for food. Large flocks of wild turkeys forage for seeds and fruits in agricultural fields and other areas. Mourning doves and dark-eyed juncos often travel in small to medium sized flocks. Mixed species flocks of chickadees, nuthatches, tufted titmice, and woodpeckers search for insect prey, in egg or pupa stage. Large flocks of snow buntings, sometimes consisting of 100 or more birds, can be seen foraging within open fields. Winter waterfowl, such as common mergansers and common goldeneye, feed on fish, mollusks, crustaceans, and aquatic plants in open water areas such as the Niagara River. Bald eagles hunt fish in those same open water areas.

To conserve energy, over-wintering birds seek sheltered areas for use as night-time roosts, such as conifers and other evergreens (lone trees and groves), tree cavities, bird houses, and dense thickets. Such areas provide greater thermal shelter from wind-chill and are often located close to feeding areas, further helping these birds conserve critical energy reserves. Woodpeckers excavate cavities in late autumn that serve as winter roost sites. Some songbirds (e.g., eastern bluebirds, black-capped chickadees, white-breasted nuthatches, tufted titmice) roost together in tree cavities, woodpecker holes, and bird houses to capitalize on shared body heat. During frigid weather, ruffed grouse and snow buntings are known to fly into snow drifts to take advantage of the insulative values of snow. On sunny winter days, birds will often perch in exposed areas to capitalize on solar warming.

One way that people can help over-wintering birds survive the challenges of food scarcity and cold temperatures during Buffalo-Niagara winters is to establish bird feeding stations. Bird feeders, when properly maintained, can help individual birds survive and can raise the songbird carrying capacity (i.e., the number of individuals that can be supported) in the immediate area around the feeding station. It is best to provide a good variety of seed types, as well as energy-rich suet and water (ideally using a heated bird bath). Black oil sunflower and nyjer (AKA thistle) are the best seeds for attracting winter finches, evening grosbeaks, and red-breasted nuthatches. Consider placing white millet or other small seeds on the ground to attract ground-feeding birds such as dark-eyed juncos, American tree sparrows, and mourning doves. In addition to helping birds survive, bird feeding is a great way to attract a diversity and abundance of songbirds for close observation and enjoyment (including species in your neighborhood that you might otherwise not see).  It helps to bring them out of the woodwork, so to speak, especially during cold and snowy weather. If a feeding station is not a good option for you, visit 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).

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):

  • 7:37 AM/5:18 PM EST (9 Hours, 41 Minutes)
  • 0 Hours, 40 minutes of daylight longer than at Winter Solstice

Typical Weather:

  • Normal High Temperature: 30.9° F  Normal Low Temperature: 17.9° F
  • On average, the lowest normal temperature of the year occurs during this week.

Lake, Pond, Stream & Wetland Conditions:

  • The Lake Erie water temperature off Buffalo cooled to 32°F and the Lake Ontario water temperature off Greece (Monroe County) cooled to 36°F as of January 25, 2019.
  • Water levels in most interior wetlands and vernal pools are near seasonal highs after a long period of normal or better precipitation and greatly reduced evapotranspiration rates.
  • Similarly, water levels in most ponds are close to seasonal highs.
  • Inland ponds, wetlands, and vernal pools are mostly ice-covered.
  • Streams are mostly ice and snow-covered.

Fungi:

  • With the onset of winter, most fungal fruiting bodies (e.g., mushrooms, bracket fungi) have been extinguished. 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:

  • Freezing temperatures during late autumn killed remnant grass, sedge, and rush stems. The roots of these perennial plants will survive and sprout next spring.

Wildflowers:

  • Wildflower stems died back following late fall freezing temperatures. Roots and rhizomes of perennial wildflowers will survive and sprout next spring. Seeds of annual wildflowers will do the same.

Trees and Shrubs:

  • Some American beech trees will hold their dead leaves over most of the winter.
  • A few native shrubs and vines continue to provide fruit (soft mast) that is an important winter food source for a variety of birds and mammals: cranberry viburnum, staghorn sumac, and swamp rose.
  • In addition, one non-native species, multiflora rose, provides fruit consumed by wildlife.

Insects & Other Invertebrates:

  • Freezing temperatures during late autumn 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:

  • 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 is near its peak with impressive numbers 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.
  • This continues to be 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 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 are over-wintering.
  • Winter resident raptors will continue to occur 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.
  • While most American robins have migrated south, small to medium sized flocks may still be encountered.
  • Small flocks of horned larks and Lapland longspurs and large flocks of snow buntings can be found in open farmland and other tundra-like habitats by snow buntings.
  • 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), woodchucks, and meadow & woodland jumping mice continue to hibernate. These species are true hibernators.
  • False hibernators such as the raccoon and striped skunk are mostly dormant, other than occasional feeding forays during relatively warm weather. In contrast, Virginia opossums stay active all winter other than brief denning during particularly cold weather.
  • 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, other than during extremely cold periods. Similarly, red squirrels feed from middens of pine and spruce cones.
  • Watch bird feeders after dark for nocturnal visits by southern flying squirrels.
  • Some white-footed mice and deer mice spend the winter in nests they built in woodpecker holes, bird houses, and squirrel leaf-nests. Some rehab old bird nests by adding a roof and insulation.
  • Beavers continue to feed on cut branches they cached in shallow water near their lodges during the fall, and muskrats do the same with herbaceous vegetation cached near their lodges.
  • 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).
  • White-tailed deer bucks typically shed antlers between mid December and mid February in the Buffalo-Niagara Region.

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

Chuck Rosenburg

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January 8-14, 2019 (Week 2 of 52): The Marvels of Mammal Survival Through Winter

Wild mammal species found in the Buffalo-Niagara Region exhibit amazing adaptations that help them survive food scarcity and cold winter temperatures. The most remarkable adaptation is hibernation; true hibernation to be precise. Several species of mammals in our Region are true hibernators: five species of cave bats (big brown, little brown, northern long-eared, small-footed, and eastern pipistrelle [tri-colored]), woodchuck, meadow jumping mouse, and woodland jumping mouse. These true hibernators undergo incredible biological changes, triggered by a hormone-like protein, that bring them into a death-like state which allows them to conserve enough energy to survive the winter without eating or drinking. Their body temperatures fall to that of the surrounding environment (typically below 40° F) and their metabolic rates drop drastically. The heart rate of a hibernating mammal drops to just a few beats per minute and breathing rate reduces to as few as one breath every few minutes. These animals survive on body fat accumulated during heavy feeding in late summer and fall. Most hibernator species have relatively large amounts of brown fat, another marvelous over-wintering adaption. Brown fat is capable of greater heat production than white fat because it is packed with mitochondria which burn energy and produce heat. It surrounds vital organs and can provide heat on demand, by hormonal release. Finally, these mammals retreat for hibernation to relatively warm, protected areas (e.g., caves for bats, underground burrows for woodchucks) that further aid in conserving critical energy reserves.

Another group of mammals that retires to burrows and dens to endure the winter months are sometimes referred to as false hibernators. This group of winter dormant mammals includes raccoon, striped skunk, and black bear. These animals feed heavily in fall to build up body fat, then retire to burrows, tree cavities, and other protected areas to “sleep” for most of the winter. Raccoons and skunks may emerge occasionally during relatively warm periods to feed. False hibernators do not experience the radical biological changes experienced by true hibernators. Their body temperatures fall relatively little and metabolic rates drop less significantly than true hibernators. The most dramatic changes are displayed by black bears, which enter a state called carnivorous lethargy that is relatively similar to true hibernation. Their heart rates are significantly lowered but body temperatures fall only about 10°F (substantially smaller drop than for true hibernators). It is noteworthy that black bears utilize brown fat, like most true hibernators. Also, black bear cubs are born between mid-January and early February while sows are in this lethargic state.

Eastern chipmunks have a slightly different approach to winter dormancy than the above-listed species. They hoard food in their dens (versus building up large fat reserves) and then awaken from torpor frequently to feed. They may also forage aboveground during relatively mild weather.

All three species of tree bats found in our Region during summer months (eastern red, silver-haired, and hoary bats) migrate south for the winter, typically departing in late September and October as insect prey becomes scarce. These bats over-winter primarily in the southeastern United States. Many of these bats breed in their wintering area and return to our Region to give birth and raise young. Those in the northern part of their wintering range may hibernate for a portion of the winter. It is worth noting that many of our Region’s cave bats migrate relatively short distances from their summer ranges before they enter hibernation.

A large percentage of our Region’s mammals do not migrate, hibernate, or otherwise go dormant during winter months. They stay active all winter, focused on surviving long cold periods with limited food supplies by continuing to feed and conserving as much energy as possible. Behavioral changes and physical adaptations help them survive. Some of the behavioral adjustments start in autumn, with most mammals feeding actively to build up fat reserves under the skin and elsewhere (e.g., in the tails of beavers). In addition, some species cache food for consumption during lean winter months. For example, eastern gray squirrels and southern flying squirrels gather and stash or store acorns and other hard mast for winter feeding. Similarly, red squirrels form middens of pine and spruce cones. White-footed and deer mice stockpile small fruits and seeds in nests and nearby “pantries.” Beavers cut, transport, and cache branches in shallow water near their lodges for wintertime feeding. Muskrats have a similar practice of caching herbaceous vegetation near their lodges. Mink occasionally hoard fish and other prey for later consumption.

The most common behavioral changes of winter-active mammals focus on conserving energy. For example, white-footed mice and deer mice construct insulated nests in woodpecker holes, bird houses, squirrel leaf-nests, and old bird nests (rehabbed by adding a roof and insulation). Some small mammals, such as meadow voles and short-tailed shrews, adopt a subnivean (defined simply as “underneath snow”) lifestyle. There they are sheltered from extreme cold air temperatures because snow serves as an effective insulator, especially when it is relatively dry and fluffy. Virginia opossums, which stay active all winter, remain sheltered in burrows and other protected areas when conditions are especially cold. Many other winter-active mammals also den-up during particularly cold periods, including several species that do so in small groups to capitalize on shared body heat. Examples of these “huddlers” include striped skunks, eastern gray squirrels, red squirrels, beavers, muskrats, white-footed mice, and meadow voles.

White-tailed deer congregate in protected areas called “deer yards,” sometimes in large numbers, especially when snow cover is deep. Such areas are densely vegetated (often dominated by pines and other conifers) and therefore provide greater thermal shelter from wind-chill and accumulate shallower depths of snow. These yards are often located close to feeding areas which further helps deer conserve critical energy reserves during harsh winter periods.

Once cold weather sets in, winter-active mammals must produce enough metabolic heat from food or fat reserves to offset heat and energy lost to their cold surroundings. That is particularly challenging for shrews and other small-bodied mammals that are especially prone to heat loss. Shrews are remarkable in that they utilize brown fat, like most true hibernators and black bears, with its heat production benefits.

The most common physical adaptation found in winter-active mammals is a heavy coat of fur. For example, coyotes and red and gray foxes shed their thin summer coats and replace them with thick winter coats consisting of a dense wooly underfur overtopped by long coarse guard hairs. The winter coat of white-tailed deer is similar except that their guard hairs are hollow and therefore are particularly effective at insulating. Beavers step it up another notch with their extremely dense underfur plus their meticulous preening and oiling of the underfur to keep it waterproof. These specially designed coats of fur, combined with thick layers of fat built up during fall feeding, provide effective insulation that helps winter-active mammals minimize losses of body heat.

Another interesting physical adaptation is countercurrent blood flow in the tails of beavers, muskrats, and river otters which allows these animals to avoid losing excessive amounts of body heat and to keep tails from freezing. A dense network of veins occurs in close contact with arteries where warm blood going out to the tail meets cold blood coming in from the tail. The warm blood heats cold blood returning to the animal’s core, and the cold blood cools warm blood going out to the tail. In this way, the tail is constantly cold but warm enough to keep tissues alive. Moreover, less body heat is lost by reducing the temperature gradient between blood in the veins and cold water temperatures.

The next time you see a gray squirrel, red fox, beaver, or white-tailed deer, consider the remarkable adaptations that allow them to survive the typical food scarcity and cold temperatures associated with Western New York winters.

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):

  • 7:45 AM/5:01 PM EST (9 Hours, 16 Minutes)
  • 0 Hours, 15 minutes of daylight longer than at Winter Solstice

Typical Weather:

  • Normal High Temperature: 31.2° F  Normal Low Temperature: 18.7° F

Lake, Pond, Stream & Wetland Conditions:

  • The Lake Erie water temperature off Buffalo cooled to 37°F and the Lake Ontario water temperature off Greece (Monroe County) cooled to 38°F as of January 11, 2019.
  • Water levels in most interior wetlands and vernal pools are near seasonal highs after a long period of normal or better precipitation and greatly reduced evapotranspiration rates.
  • Similarly, water levels in most ponds are 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.
  • 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 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.
  • False hibernators such as the raccoon and striped skunk are mostly dormant, other than occasional feeding forays during relatively warm weather. In contrast, Virginia opossums stay active all winter other than brief denning during particularly cold weather.
  • 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, and muskrats do the same with herbaceous vegetation cached near their lodges.
  • 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).
  • White-tailed deer bucks typically shed antlers between mid December and mid February in the Buffalo-Niagara Region.

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

Chuck Rosenburg

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