Spotted Sandpipers are a relatively easy shorebird to identify, with their spotted breasts, their constant body-bobbing/teetering and the stiff beat of their wings. Although they are a shorebird, they can be found near freshwater ponds and streams throughout North America. Spotted Sandpipers differ from most birds in that the male and female roles are completely reversed when it comes to breeding – from courtship to parental care. The females establish and defend their territory, often arriving on nesting grounds before the males. Females court the males, performing display flights as well as strutting displays on the ground. Males, usually less aggressive and smaller in size, do the lion’s share of incubating the eggs and brooding the young chicks.
The relationship between beavers and waterfowl is a strong one. In creating ponds and wetlands, beavers provide valuable waterfowl habitat. Beaver ponds are attractive to most dabbling duck species, particularly American Black Ducks and Mallards (pictured). Dead snags that are often found in beaver ponds provide Hooded Mergansers, Common Goldeneyes, Buffleheads and Wood Ducks with nesting cavities. During spring and fall, beaver ponds are used by migrating waterfowl, such as Green-winged Teal and Ring-necked Ducks, for the fuel they provide (aquatic invertebrates, plant seeds, tubers, buds and rhizomes). Waterfowl surveys in 2002 in Wyoming found that rivers and ponds with beavers had 75 times more ducks than those without beavers.
The House Sparrow’s (also known as English Sparrow) reputation leaves a bit to be desired. It is an introduced species which has thrived in North America to the point where it is considered a nuisance species and an agricultural pest. Its tendency to displace native birds such as Eastern Bluebirds and Tree Swallows from nest boxes does not endear it to many bird lovers. However, one has to acknowledge the fact that male House Sparrows are the exception rather than the rule when it comes to parenting. Males help choose the nest site, build the nest, incubate the eggs, brood and feed the nestlings and keep the nest clean by removing the nestlings’ fecal sacs. That’s more than can be said for some of our most admired species, such as male Ruby-throated Hummingbirds, which disappear shortly after copulation.
Looking as if it were stuck to the vertical cliff wall by crazy glue, a raven’s nest is often used for several years in a row. The nestlings remain in the nest for about 5 to 7 weeks, during which time they go from being an orange/pink color, sparsely covered with gray down, to the black plumage of an adult. The pictured nestlings are approximately five weeks old, and have just started to exercise their wing muscles in preparation for their first flight. They are panting with open beaks in an attempt to dissipate the heat of an unrelenting May sun. Within a week or two they will leave the nest, but will stay nearby for a few days. I couldn’t get close enough to give this nest a smell test, but supposedly raven nests can have an unbelievably unpleasant odor (due to the remains of leftover food/ carrion and feces).
This is the time of year when it pays to watch where you walk – there are a number of ground nesting birds, some of which, including killdeer, may choose your lawn or even your garden to build their simple “scrape” nest. Typically killdeer nest on the shoulders of roads, gravel roof tops, fields and gravel parking lots. The nest is very primitive, and there’s actually very little to it — killdeer scrape a slight depression in the ground, to which they often add bits of material, including white objects such as shells and bones. Their pigmented eggs are extremely well camouflaged. The young precocial killdeer chicks are on their feet and feeding themselves as soon as their down feathers dry. (Photo by Sadie Richards)
Numerous displays lead up to the mating of great blue herons – neck stretching, bill clacking, wing preening, circling flights, twig shaking, crest raising, neck fluffing, to name but a few. After this elaborate courtship comes copulation, which is not nearly as showy. Copulation typically takes place on the nest. The male places one foot gently in the center of the female’s back. The female leans forward, bends her ankles and holds her wings slightly away from her sides while the male lowers himself, often flapping his wings. Once the job is done, the male flies off. If you look closely you can perhaps make out that the male is grasping the female’s head/neck while copulation takes place.
Killdeer arrived back in northern New England last month and have already begun nesting. Being a ground nester, the killdeer has many mammalian predators from which it needs to protect its eggs, including weasels, skunks, opossums and raccoons. Nesting killdeer have a number of responses to predators, which include several different types of distraction displays which draw attention to the bird away from its nest. One of the most common displays is to feign injury by assuming a position which makes the bird appear vulnerable. When a predator approaches, the bird runs away from the nest, crouches with its head low, wings drooping and tail fanned and dragging the ground to display its rufous rump-patch. The predator typically follows, seeing an easy meal, and as soon as it gets too close for the killdeer’s comfort, the killdeer continues to lead it off by alternate flights and sprints.
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.
Winter provides an opportunity to get a close look at last year’s bird nests to see who might have been nesting under our very noses without divulging their presence (Peterson’s Field Guide to Bird Nests is a great resource). A walk near wetlands in winter often reveals a yellow warbler nest. It is quite easy to recognize as it is lined with downy plant fibers and is fairly thick-walled. Yellow warblers are often victims of brown-headed cowbirds, which lay their eggs in other birds’ nests and therefore avoid the labor of raising their own chicks. Many birds don’t recognize a cowbird’s egg, and incubate it and raise the young cowbird chick as their own. Yellow warblers, however, can distinguish between their eggs and a cowbird’s. Upon returning to her nest and finding a cowbird egg (often laid before the host bird begins laying her eggs), the female yellow warbler simply builds another nest right on top of the nest containing the cowbird egg, and begins anew. As many as six stories of nests have been found with cowbird eggs buried in each layer.
Most songbirds only use their nest once. After their young have fledged, the nest is usually abandoned. In the natural world, recycling has been a way of life for a long time, and abandoned bird nests are not about to be wasted. In the spring, the material used in old nests is often re-used by birds building new nests. But long before this occurs, white-footed mice and deer mice, both of which remain active year round, often use old nests as larders where they store food for the winter. Occasionally they even renovate a nest in the fall in order to make a snug, winter home. They do this by constructing a roof (of milkweed fluff in this photograph) over the nest, which serves to insulate it. Use caution if you come upon such a nest– it could well be inhabited! (Thanks to Sara and Warren Demont for the photo op!)
Now that the leaves are off the deciduous trees, it is much easier to see where songbirds nested this past summer. Just as every songbird species has a specific song unlike that of other species, each species also constructs nests that are very similar to each other, but not to other species’ nests. Thus, one American robin nest looks a lot like any other American robin nest – nests of one species are usually found in roughly the same kind of habitat, with the same dimensions and similar building materials. Sometimes there are key characteristics that help with identification – grape vines and a lining of rootlets told me a gray catbird built the nest in the photograph. (Plastic told me humans weren’t far away.) Most songbirds only use their nest once; after the young have fledged, they abandon their nests. Before the weather and/or critters recycle this year’s nests, take advantage of the opportunity to examine these gems of avian architecture up close. (A federal permit is needed in order to collect bird nests.) A good book for nest identification is Peterson’s Field Guide to Bird Nests.
I had to laugh recently when I noticed a chain reaction going on in a Great Blue Heron nest I was watching. There were five chicks, and one of them yawned. At least I presume it was a yawn, though perhaps it could have be re-aligning its beak or perhaps cooling off. Exactly like humans, each of the remaining four birds followed suit and proceeded to stretch their beaks open wide in succession. It struck me as quite comical, especially when I discovered myself yawning as I observed the heron chicks doing the same.
In New England, Dark-eyed Juncos typically have two broods in a summer. The second-brood nest in the photograph contains the first of probably four or five eggs which are laid one day at a time. The egg lies on a soft lining made from the hair of a White-tailed Deer. Unlike most songbirds, Dark-eyed Juncos build their nests in a wide variety of sites, from the ground up to eight feet high in trees. Often they are in a small cavity on a sloping bank (well hidden by surrounding grass), under a protruding rock or among tree roots. But they’ve also been found under fallen tree trunks, on supports underneath houses on stilts, in barns or lofts between hay bales, in vines on the sides of buildings, on window ledges and light fixtures and in hanging flower pots. It’s not unheard of to find a Dark-eyed Juncos relining the old nest of an American Robin.
Great Blue Heron chicks are getting big enough so that you can easily observe them (can you find all four?). Occasionally you can even detect flies and other insects buzzing about them, which, given the fact that nest sanitation is not a priority for herons, is not surprising. While the parents do toss the eggshells out of the nest, feces, partly eaten prey and even dead chicks often remain in the nest. Also, parents feed their young by regurgitating into the nest and the chicks will regurgitate when disturbed. Unlike most song birds, Great Blue Herons re-use their nest year after year. It is quickly apparent why they add more sticks and boughs to their nest every breeding season – were that housekeeping for humans was that simple!
The nesting habits of Cliff Swallows are fairly unusual in that these swallows are colonial nesters. Here in the East you can find 20 or 30 of their nests under a bridge or the eaves of a barn (and occasionally on cliffs). In the West, colonies consist of up to 3,500 nests! The construction of their gourd-shaped nest requires between 900 and 1,200 trips to mud puddles or stream banks, where they gather a mouthful of mud in the form of a pellet. Often two swallows will build nests side-by-side, sharing the wall of mud that separates them. Unfortunately, according to the most recent Vermont Breeding Bird Atlas, the Cliff Swallow population in Vermont has declined by 48% in the past 25 years, a fact which is attributed to competition with House Sparrows, a decline in insects due to diminishing farm land, and destruction of nests by humans. These birds are more important insect predators than ever, with the bat population having suffered such a decline recently due to white-nose syndrome.
Great Blue Herons are returning to their breeding grounds in northern New England, where they typically nest in colonies. Unlike the nests of songbirds, heron nests are re-used year after year. While an individual heron does not usually choose the same nest every year, they usually return to the same colony. While some colonies are active for only a few years, some have been known to be active for over 70 years. Because nests can be located up to 100 feet high in a tree (typically a dead snag in the Northeast), you rarely have a bird’s eye view of nesting activity. However, if you go to Cornell’s new live great blue heron web cam site (
) you can see every movement made by the great blue herons currently nesting in Sapsucker Woods in Ithaca, NY.
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.