It’s no wonder that the hedgerow I was walking along yesterday seemed alive with the sound of song sparrows – not only was there an abundance of these small, brown birds, but each one’s peak song rate is 300 songs per hour! You can hear the song sparrow's song by going to Cornell's "All About Birds" site at http://www.allaboutbirds.org/guide/Song_Sparrow/sounds
Eastern bluebirds are back, and are already staking out territories. Although people are often encouraged to clean out bluebird houses before bluebirds return, experiments show that these birds have a definite preference for nesting boxes containing old nests! The male eastern bluebird displays at his nest cavity or nesting box to attract a female. He brings nest material to the hole, goes in and out, and waves his wings while perched above it. Once he attracts and mates with a female, he takes a break. The male does not participate in nest building, nor does he incubate the eggs, or brood the young. He does, however, resume working in time to help the female feed their nestlings.
Black bears recently emerged from four or more months of winter dormancy, during which time they did not eat, drink, defecate or urinate. After some intense foraging in the fall, black bear activity slows down, and eventually, as the food supply dwindles, they enter dens. During the months when they are dormant, black bears have what is called a fecal plug that blocks their gastrointestinal tract. Much of this plug consists of hair that the bear ingests while licking its coat. When the bear emerges in the spring, this plug is expelled. The pictured plug is roughly 6” long and 3 ½” at its widest point.
Eastern phoebes have arrived back in central Vermont. Their “phee-bee” song is a welcome sound of spring, but one can’t help but be concerned about their welfare -- the temperature outside this morning was 10 degrees F. Ninety percent of this flycatcher’s diet consists of insects (26% of which is made up of bees and wasps), and there aren’t many flying around in this weather. Fortunately, however, ten percent of a phoebe’s diet is small fruit, some of which still clings to trees and shrubs even at the end of a long winter.
The deep snow and persistent cold weather this winter has made life very difficult for animals that stay active, as they must find food. Barred owl sightings are up in Vermont, probably as a result of the harsh conditions this winter. The small mammals that make up much of a barred owl’s winter diet have been well hidden beneath several feet of snow. Thus, visits to bird feeders, where both birds (barred owls will prey on birds up to the size of a ruffed grouse) and small rodents can be found, are frequently made by barred owls. The barred owl pictured naps 40 feet above a bird feeder during the day, but one hopes he fills up on resident rodents during the night.
Something about the snow conditions (4” of powder on top of a hard crust) must be conducive to sliding on your belly, at least to members of the weasel family. Today I found numerous places (all down hills) where a mink had chosen to either save itself some energy or have fun (or both) by sliding down a slope. The longest run was about 25 feet, the shortest about 2 feet. The troughs, or slides, were roughly 3 1/2” in diameter. Interesting to note that whereas river otters will slide down hills, on flat terrain, and even sometimes up slight inclines, mink appear to limit their sliding to downhill.
While some members of the weasel family, particularly river otters, are known to slide downhill as well as on flat terrain, fishers are not, yet I have found two different fisher slides in the snow in as many days. One of the slides was downhill; it began at a hollow tree where the fisher had been resting and extended to the wetland below. The other instance, pictured in the photograph, occurred on level ground. The slide was about 15 feet in length and roughly 8” in diameter.
With two feet of snow still on the ground, 5” of which fell this morning, finding a firefly crawling on top of the surface of the snow was unexpected, to say the least. Unlike most firefly species, which overwinter as larvae, winter fireflies (Ellychnia corrusca) spend the winter as adults and are often seen on tree trunks through the colder months. The adults have no light organ, but larvae and pupae do. Winter fireflies are sometimes so abundant on maple trunks this time of year they are commonly found in sap buckets, so much so they’re often considered a pest.
Great blue herons returned to central Vermont on time – just as ponds and lakes are starting to have some open water. It will be three months or so before these birds are nesting, often in colonies or rookeries that can consist of up to several hundred pairs. Although they are primarily fish eaters, great blue herons do patrol upland fields for rodents, especially on their wintering grounds.
The single-scaled buds of pussy willow flowers are starting to open! There are many species of willows – 100 in North America – and several of the smaller ones are referred to as pussy willows. Probably the species most commonly called pussy willow is the American pussy willow, Salix discolor. When the flower buds open, you see the immature silvery, furry flowers, which are reminiscent of a kitten’s fur. As the flowers mature, they emerge up through the “fur.” Willows have separate male and female flowers (photos to be posted later in the spring) which are borne on separate shrubs.
The Killdeer, technically a shorebird and member of the Plover family, is one of the earliest migratory birds to return to Vermont, typically arriving in mid-March. These birds migrate during the night as well as the day, and generally travel in flocks of 6 to 30 birds. Nesting will begin in April, when they make a shallow scrape in the ground and the female lays 4 mottled eggs.
Tracks in the woods nearby indicate that black bears are beginning to emerge from hibernation. This is the hardest time of the year for black bears – even though they are omnivorous, the bulk of what black bears eat is plant material. In the spring their diet consists primarily of grasses and other herbaceous plants, which are very scarce this early in the year. As a result, most bears lose weight in the spring and are still dependent, in part, on the fat they acquired last fall.
Bald eagles begin their monogamous, lifelong partnerships with a spectacular courtship, involving vocalizations and acrobatic flight displays. According to Cornell’s Birds of North America Online, the courting birds, in what is referred to as their cartwheel display, “ fly to great altitude, lock talons, and tumble/cartwheel back toward earth” with the pair breaking off this display at the last moment to avoid collision with the ground. Yesterday, in Windsor, Vermont, an lucky bystander was fortunate enough to observe the culmination of this display -- a pair of eagles mating.
Some ornithologists were predicting the extinction of wood ducks around the turn of the 19th century, due to loss of wetland habitat and hunting pressure, but fortunately, they were wrong. Protection from harvesting by the Migratory Bird Treaty Act of 1918 allowed their population to rebound. The return of paired wood ducks in March (particularly the males) adds much glamour to otherwise drab rivers, marshes and wooded swamps. (Females, as is typical in the bird world, are a drab brown – far less colorful than the males.)
Even though beavers build a stock pile of branches near their lodge which they swim out to and retrieve food from every two weeks or so throughout the winter, their desire for fresh cambium doesn’t disappear. In the spring, as soon as there is an opening in the ice, they are up and out, looking for poplar, alder and birch and the first herbaceous plants to appear. Every spring I celebrate finding the first beaver tracks in the snow. One can only imagine how sunlight, fresh air and fresh food must feel to a creature who has spent the past 4 months in the dark, damp confines of a lodge.
In amongst all the signs of spring that are appearing, I saw some winter visitors, bohemian waxwings, this morning, gorging themselves on crab apples. Flocks of these birds occasionally appear in Vermont and New Hampshire throughout the winter, having flown down from Canada seeking sweet winter fruits. As their name indicates, they are nomadic, and rarely linger long in one place. Soon they will vanish, heading north to breed. In the summer, bohemian waxwings feed heavily on insects, but during the winter, keep an eye out on your fruit trees for these strikingly beautiful birds.
Amazing – even with several feet of snow on the ground in central Vermont, eastern chipmunks are emerging right on time, scurrying around on top of the snow foraging for food. All winter they have been somewhat torpid down in their tunnels (elaborate ones measure up to 32 feet in length), waking to feed on their stored food supply every two weeks or so. It must feel good see daylight, even if the weather is inclement.
The recent return of male red-winged blackbirds is a welcome event, for it signals one of the first real signs of spring. Females will follow in two or three weeks, but meanwhile you can hear the familiar “konk-la-ree” song of the males, as they perch prominently near wetlands, displaying their boldly-colored epaulets, or shoulder feathers, staking out their territory. Once available, insects will provide the majority of the redwings’ diet, but until then, seeds from a variety of plants, including many weeds as well as grains, make up the bulk of what they consume.
Today the drumming of a hairy woodpecker could be heard reverberating through the woods – a reassuring sign that spring is coming. At this time of year most drumming is being done by males in an attempt to establish and defend a territory. Soon both sexes will be drumming as part of courtship and pair formation. Although I have a hard time telling the downy and hairy woodpecker drums apart, the hairy’s is said to be more rapid, with longer pauses between bursts than the drumming of a downy woodpecker.
Red foxes are opportunists, and will consume whatever is available, be it plant or animal. During the winter their meals consist largely of mice, rabbits, hares, any birds they can catch and carrion. Amazingly, they are capable of hearing the low-frequency noises of small mammals through two feet of snow! Red foxes had recently picked clean this white-tailed deer skull which lay in nearby snow-covered woods.
I’ve spent most of the past week at the J. N. "Ding" Darling National Wildlife Refuge which is on the subtropical barrier island of Sanibel in the Gulf of Mexico. The refuge is part of the largest undeveloped mangrove ecosystem in the United States and attracts an impressive number of migratory as well as breeding birds. My daughter Sadie and I were fortunate enough to observe a pair of yellow-crowned night herons beginning the construction of their nest. At this point, the male and female have different roles, which was very evident from their behavior. The male would leave the nest and break a twig off a nearby shrub, return to the nest with it, present the twig to its mate and then preen her back while she placed the twig in the nest. It made me wonder if two humans building a house together could work as cooperatively and harmoniously. ( Later on in the nest-building process, both adults may gather and construct the nest.) The next blog entry will focus on the natural history of New England!