Common ravens are known for their aerial acrobatics, often doing rolls and somersaults and other amazing tricks. According to Cornell Lab of Ornithology, one bird was seen flying upside down for more than a half-mile. Young birds are fond of playing games with sticks, repeatedly dropping them and then diving to catch them in mid-air. The pictured raven, however, was much too busy to be doing cartwheels in the sky. It has a nest with eggs nearby, and during its morning patrol encountered a red-tailed hawk which it drove out of sight in a matter of seconds. Although small mammals make up most of a red-tail’s diet, they are known to also prey on smaller birds, including defenseless nestlings, which the ravens will have in the next few weeks. (Because of the angle, the 24-inch-long, 53-inch-wingspread raven looks disproportionally larger than the 19-inch-long, 49-inch wingspread red-tail.)
With winter temperatures still upon us, it can be challenging to find signs of spring in the hills of Vermont. However, subtle signs do exist if you know where to look! Notice the fresh greenery in this nest – it confirms that recent refurbishing has taken place by returning red-shouldered hawks. Roughly two feet in diameter, a red-shouldered hawk’s stick nest is lined with moss, lichen, bark and conifer sprigs. Other items that have been used as building material for these raptors include ears of corn, corncobs, corn husks, tissue paper, nests of songbirds, straw, mullein, leaves, twine, various deciduous tree leaves, entire plants, dried tent caterpillar webs and plastic grocery bags. The pictured nest will serve as a nursery for two to five red-shouldered hawk chicks in about a month’s time, and as the nesting season progresses, sprays of conifers such as the hemlock sprigs you see here will continue to be added.
It’s well known that owls have an acute sense of hearing — some species, such as the barn owl, hunt nocturnally by sound alone. An owl’s asymmetrically-placed ears are located beneath the feathers at the edge of its facial discs. This placement, along with the shape of the external ear canals, is thought to contribute to an owl’s keen ability to locate sound. The flesh-colored fold of skin that you see in front of this barred owl’s ear is movable, and reflects and concentrates sound waves coming from behind the bird.
A cooper’s hawk made short work of a mourning dove near my bird feeder recently, killing and apparently, given the large number of feathers scattered on the snow, plucking the dove on a nearby snow bank. If you look closely you can see whole sunflower seeds in amongst the feathers. These came from inside the mourning dove’s crop. Mourning doves generally feed quickly, filling their crop with seeds which they digest later, when they’ve found a safe spot in which to roost. Unfortunately for this particular dove, it didn’t live long enough to have that opportunity.
Raucous crow and raven calls alerted me to the fact that something, most likely a bird of prey, was in the area (crows and ravens often mob and harass hawks and owls). Through the trees I got a glimpse of a raven flying beside another bird that dwarfed the raven. Soon there were two of these large birds, dipping and diving in the wind, seemingly enjoying themselves no end. They turned out to be juvenile bald eagles, last year’s young. Perhaps they were practicing for the acrobatic courtship flight displays they’ll be performing in three or four years.
If the majority of your diet consisted of one type of food, and that food was concentrated in certain spots, it would make sense to frequent those spots. Bird-eating predators, such as the sharp-shinned hawk, are frequently seen at bird feeders for this very reason. Although not very large — roughly the size of a blue jay (the female is a third again larger than the male) — this accipiter is a formidable predator, and one which causes feeder visitors to either disappear or become motionless for a considerable amount of time. The sharp-shinned hawk is the smallest hawk in North America and derives its common name from the sharp-edged “shin” on the lower part of its legs. Its long tail and short wings make it extremely adept at flying through dense woods in search of small birds.
Dramatic stories are not limited to the snowy woods of northern New England! This photograph was taken in Jamaica Plain, a neighborhood of Boston, Massachusetts. It tells the story of a small bird being killed by a relatively small bird of prey, most likely a Cooper’s Hawk or a Sharp-shinned Hawk – both are accipiters and predators of small birds (as well as other prey). Because their wingspans overlap, there’s no way to unequivocally state which of these raptors left this imprint, but whichever it was, it was successful, judging by the feathers and blood that remain. Both of these hawks are listed as Massachusetts Species of Special Concern, with the Sharp-shinned hawk sighted most often in the western part of the state. (Photograph by Sadie Richards)
Roughly six to ten hours after consuming prey, owls, hawks and many other birds cough up a small pellet that consists of the indigestible bones, fur, etc. of the prey it’s eaten. The barred owl in this photograph was in the process of coughing up such a pellet. While pellets are hard to come by (they are well camouflaged on the forest floor), owls caught in the act of producing them are even more rare!
Broad-winged Hawk chicks spend their first five or six weeks in the nest being fed small mammals, toads, nestling birds and a variety of invertebrates by their mother. They then fledge, but for the next two weeks these young birds continue to use the nest as a feeding (food is still being provided for them) and roosting site. At about seven weeks of age they begin capturing their own prey, and remain on their parents’ territory for the next month or two — just enough time to learn the ropes before migrating south for the winter, which they are doing right now (peak migration is mid-September).
This is pure conjecture, but here goes. Barred Owls are known to consume small mammals, birds, reptiles, amphibians, fish and invertebrates. I have repeatedly encountered a Barred Owl lately near a pool of water in a brook that has all but dried up. Fish have become trapped in this pool due to the dryness of the summer, and are easy pickings for predators. Even though studies have shown that fish are a very small percentage of a Barred Owl’s diet (2.5% in owls from New Jersey, New York and Connecticut during the breeding season), I am betting that the owl that I flushed yesterday that was perched right next to the isolated pool in the brook was spending the day (and night?) at his favorite fishing hole. Three times it took off from its perch as I approached, but only flew a few feet away each time. Perhaps fish or frogs kept it from disappearing further into the woods.
Hardy birds that they are, Great Horned Owls are one of the earliest nesting birds — you can find them on nests in January, February and March, even in northern New England. Eggs are incubated for about a month, typically in March or April with young usually hatching in May or June. The nestlings remain in the nest for six or seven weeks before fledging. Unable to fly until they’re ten or twelve weeks old, the fledglings follow their parents around and continue to be fed and cared for by them until the fall. These two fledglings were sticking close together as they made their raspy begging calls from high in a white pine. Both their calls and the down that was visible on their heads told me that they were this year’s young.
On some of the hot days we’ve had recently, my thoughts have turned to Turkey Vultures and their ingenious way of staying cool. They defecate on their legs and the subsequent evaporation cools the birds while strong acids kill bacteria.
The Red-tailed Hawk nest that produced two fledglings last year is in use again this spring. In the past month the nestlings have gone from tiny white powder puffs to nearly equaling their parents in size. Down is still visible, especially on their heads, but contour feathers are quickly replacing them on other parts of their body. Soon there will be wing stretches and flapping, as well as hopping about on nearby branches in preparation for fledging.
Although you would think that no predator would think of preying on, much less eating, a striped skunk, there are a few mammals, including coyotes, foxes and bobcats, that do just that, but only if they are in danger of starving. One predator that routinely dines on skunks is the great horned owl. One summer night I made out the silhouette of an owl flying in my direction, and as it flew by me its identity was confirmed by the skunk-like odor that accompanied it.
The red-tailed hawk nest that produced two chicks last summer is once again occupied by a pair of red-tails. A conifer sprig adorning the outside of the nest was the first clue that a second brood might be in the works. Yesterday I saw both male and female return to the nest carrying strips of bark, which the female applied to the lining of the nest. Mid-March is when red-tails typically are building or refurbishing their nest and laying eggs. They begin incubating as soon as the first (of 2 – 3) egg is laid, with the male and female both participating. This photograph was taken at the changing of the guard.
There are two subjects in this photograph – one is dark and round (left) and the other is whitish-yellow and brown, and string-like (right). One came out of a barred owl’s mouth; the other came out the opposite end. Do you know which is which? The round, brown object is an owl pellet which owls (and many other birds) cough up roughly 6 – 10 hours after consuming a meal. It is just about odorless, and consists of the indigestible parts of the owl’s prey — bones, teeth and nails wrapped in the fur of, in this case, a vole. (The fur keeps sharp bones from tearing the owl’s esophagus when the pellet is coughed up.) Different owl species have different sized pellets, and typically the larger the owl, the larger the pellet. (The average barred owl pellet is 2 ½” long and 1” wide.) A great gray owl pellet (3”-4” long and 1 ½” wide) I found contained the skulls of three small rodents, in addition to other bones. The whitish substance is the owl’s semi-solid waste. It consists of white uric acid and feces which are excreted through the bird’s cloaca, an opening that is used not only for waste disposal, but also for mating and egg laying.
As dusk approached, a Redhead (Aythya americana) drake repeatedly disappeared under water, coming up with a mouthful of aquatic vegetation each time it dove. Suddenly an agitated Crow started cawing nonstop. Soon thereafter a Bald Eagle soared overhead, scanning the open water for its next meal. The Redhead immediately dove, and wasn’t seen again for several minutes. Knowing it couldn’t hold its breath for that period of time, I began looking more carefully for where it had surfaced. Eventually I found it seeking shelter from above, tucked under a snag which had fallen into the pond.
One night this week I became aware of a series of whistled “toots,” all the same pitch, coming from the adjacent woods. This far-reaching, distinctive call comes from a surprisingly small owl, the Northern Saw-whet — one of our most common owls, whose common name comes from the “skiew” call that is made when it is alarmed. This sound has a resemblance to the whetting of a saw. Although a Saw-whet only weighs about as much as a robin, you would never know it from the volume and carrying power (over 300 yards) of its call. Typically the male calls only during the mating season, in an attempt to attract a female with whom it will mate. The female then selects the nesting cavity, typically a Northern Flicker or Pileated Woodpecker hole, usually in March or April. This pint-sized raptor (weighing less than 3 ounces, and measuring 8 inches in length) feeds mainly on deer mice. Unlike most owls, it does not swallow the mouse whole, but rather tears it in half, leaving the second half for another meal.
Given the right lighting, it’s very easy to see how red-tailed hawks (Buteo jamaicensis) got their common name (although the tail of juvenile red-tailed hawks is brown for their first two years). Central Vermont and New Hampshire is at the northern end of the red-tailed hawk’s year-round range – if they live much further north, they usually migrate south for the winter. This common bird of prey typically inhabits open areas interspersed with trees. It is usually observed soaring in wide circles over a field, or perched high in a tree, where it sits and waits, keeping an eye out for prey such as mice, voles, rabbits and hares. Once it spots a small mammal, as the red-tail in this photograph just had, it quickly takes off and uses its talons to capture its next meal.