Category Archives: Nesting birds

Readers report on robin, purple martin that stand out from other members of their flocks

 

Albino-Swallow

Photo by Jean Potter • Two barn swallows in typical plumage perch on a wire with an albino individual.

Birds of a feather, as the old saying goes, tend to flock together, but what happens when a member of the flock stands out from the rest? Although conventional wisdom mandates that being conspicuous is not helpful for most wild creatures, some of them can’t help but get attention. Different readers have brought to my attention some birds at their homes that instantly stood out.

Sara and Ed Gschwind, residents of Bristol, Tennessee, have been keeping tabs on an American robin in their yard that is showing an extensive amount of white feathers in its plumage. For the most part, this particular robin has a white head, largely white wings and extensive white in the typically red breast. “My 88-year-old mother, Nora Rockett, suggested I send a photo to you,” Sara wrote in an email.

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Photo by Ed Gschwind • A leucistic American robin enjoy time in a bird bath. Albino and leucistic birds are rather rare in nature.

Sara said that her mother, who has lived in Bristol all her life, has never seen anything like it. I replied to Sara’s email, asking for a few more details.

While the robin interacts with others of its kind, the Gschwinds haven’t seen any evidence this particular robin is attempting to nest. Ed took a photograph of the robin enjoying the water in a bird bath in the Gschwind yard.

“The robin bathes every day, and loves the water like all robins do,” Sara wrote. “The robin has been here since the robins returned three months ago. I’m trying to keep it happy.” Since the robin is a regular visitor, I agree that they’re doing a good job keeping the bird happy, since it’s not shown any inclination to leave their yard.

Tom Brake, who lives in Abingdon, Virginia, contacted me through Facebook about a male purple martin with extensive white feathers residing at the purple martin colony he has established at his home.

Purple martins are the largest member of the swallow family in the United States. Like many other swallow species, they nest in colonies. Martins are cavity-nesting birds that readily accept hollow gourds or special purple martin condominiums for nesting.

“Currently I have nests in 43 compartments with 20 being active (eggs having been laid),” Tom wrote. “Last year I had 51 pairs, and I hope to get close to being back to 60 or 70 active pairs this year. The next two weeks will be the busy time for completion of nests and laying.”

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Photo by Tom Brake • A leucistic male purple martin perches with its mate, a typical female purple martin, near a hollow gourd they may use for nesting purposes.

As for the bird showing the white feathers, Tom has named him “Leuie” because the bird is an example of leucism, a condition related to albinism.

Albinism is a genetic, or inherited, condition resulting in a complete lack of production of pigmentation. Albino birds are, for the most part, extremely uncommon. I’ve heard of a variety of birds, ranging from hummingbirds and American robins to various ducks and swallows, that have a tendency to produce albino individuals.

Leucism is another genetic mutation that causes affected birds to grow feathers that are pale or whitish overall. A faint pattern may be visible. Leucism is also uncommon, but is more common that albinism. Both the robin in the Gschwind yard and the purple martin at Tom’s home are examples of leucistic birds.

Tom noted that “Leuie” is doing well so far. “He has a mate, but their first clutch of four eggs was either thrown out by a second year male martin or discarded by themselves because they sensed non-viability,” Tom wrote in a Facebook message. “Maybe the cold, wet weather had something to do with the loss.” He noted that the same thing happened recently to two other nests.

“Leuie and mate are still using their gourd, so I expect they will re-clutch,” Tom wrote. The term “re-clutch” means that Leuie’s mate will lay a new batch of eggs and Leuie will be ready to carry out his own paternal duties to help raise any resulting young.

Albinism and leucism are not the only conditions that can affect pigment in a bird’s feathers. Some birds have the opposite problem in that they produce too much pigment, resulting in a much darker bird than what would be typical. The plumage of such affected birds is described as melanistic, which is in stark contrast to an albino bird. With a melanistic bird, the feathers are much darker than usual because of an abundance of pigment. In rare albino birds, the opposite occurs and the lack of pigment in the feathers leave them looking white. Completely albino birds also tend to have red eyes. It’s probably better for a bird to be melanistic. Albino birds tend to stick out like sore thumbs, attracting the attention of predators.

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Photo by Ed Gschwind • Compare the leucistic American robin in the bird bath with the typical robin perched in a nearby chair. Albino birds are rather rare in nature.

I’ve only seen a few albino or partial albino birds in person, although I have observed videos and photographs of such birds. During a trip to Salt Lake City, Utah, in 2006, I observed an albino Brewer’s blackbird. An albino blackbird is almost an oxymoron. This particular blackbird had a white upper body and head and a black lower body. At first, I thought it might be a small tern, but closer observation — and identification of the birds with which it was associating — eventually confirmed that it was a Brewer’s blackbird, a common species in Salt Lake City.

Those observations remain my best looks at albino birds in the wild. I’ve also seen partial albinos, including an American Crow with white feathers in its wings that inhabited the woodlands and fields at my home for several years. I’ve also observed a couple of American goldfinches over the years that would probably qualify as leucistic birds.

A few years ago, I saw an albino Red-tailed hawk while driving between Erwin, Tennessee, and Asheville, North Carolina, on Interstate 26. The hawk was often present near the North Carolina Visitors Center. I’ve also heard from readers over the years about birds such as American goldfinches and downy woodpeckers exhibiting albino tendencies.

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Photo by Jean Potter • This partial albino red-tailed hawk was spotted for several years near the state line dividing northeast Tennessee and western North Carolina.

These issues involving the absence or abundance of pigment can complicate bird identification. After all, all-white birds, from snowy owls and tundra swans to great egrets and snow geese, do exist in nature. Even in these birds, however, there’s usually some other color present to break up the uniformity of the bird’s plumage. Keep in mind that such rarities as albino individuals of such common species as house finches and American robins can show up at your feeders or in your yard. It’s just another way birds constantly surprise us.

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To learn more about birds and other topics from the natural world, friend him on Facebook at https://www.facebook.com/ahoodedwarbler. He is always posting about local birds, wildlife, flowers, insects and much more.

Birds bring their best game when seeking mates

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Photo by Dave Menke/U.S. Fish & Wildlife Service • A pair of Clark’s Grebes displays in a courtship ritual known as “rushing” or “weed dance.” Birds use a variety of strategies to attract and keep mates.

Most birds don’t bring a box of chocolates or a bouquet of roses when they take up courtship of a prospective mate, but birds have several equivalent behaviors that they employ to attract the attentions of the opposite sex. Since we recently celebrated Valentine’s Day, I thought a look at some of the more unusual courtship rituals of some of our feathered friends would be appropriate.

Birds bearing gifts. Many birds present small trinkets to a prospective mate. For instance, many male penguins make a present of a stone or pebble to female penguins. There could be more than a simple bribe behind this gift. Female penguins don’t build elaborate nests. In fact, a scrape on the bare ground, perhaps encircled by a collection of pebbles, marks the extent of their nest construction. So, the perfect pebble could be the way to winning a female penguin’s heart.

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Photo by Bryan Stevens • Northern Cardinals are beginning to pair together in anticipation of the spring nesting season.

The way to the heart is through the stomach. Observant birders may have witnessed a male Northern cardinal slip a female a morsel of food, such as a peanut or a shelled sunflower kernel. It’s a marked change for this bird. During the winter months, a male cardinal is more likely to chase a female away from a feeder rather than share food with her. However, as spring approaches, his behavior undergoes a change and he becomes content to feed next to a female cardinal, often slipping her some choice tidbits.

May I have this dance? Many species of birds perform elaborate and ritualistic dance displays. Among birds known for tripping the light fantastic are flamingoes, cranes, grouse and grebes. Cranes are one of the oldest families of birds on earth. They’re also some of the most accomplished dancers in the animal kingdom. Pairs perform very ritualistic dances that, if the performers were human, would no doubt require the services of an accomplished choreographer. Cranes mate for life and the ritual of dancing is a way to strengthen the bonds between a mated pair. The ability to dance is, apparently, not instinctive. Young cranes must practice their dance moves, a process that can take years before they master the elaborate dance.

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Photo by Bryan Stevens • A pair of Mallards find a thawed spot on a frozen pond.

Synchronized swimming. While many birds dance to impress a mate or strengthen pair bonds, grebes perform a dance that takes place completely on the surface of the water. A pair will engage in this intricate performance, perfectly mirroring the moves of the other as they literally race across the surface of the water. These dances by grebes are also known as “rushing” or “weed dance.” It’s called as a weed dance because at the culmination of the ritual, the birds usually hold some type of aquatic plants in their bills while racing swiftly over the surface of the water. Pairs that perform well together stay together, building a nest and raising young.

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An 18th century illustration of the habits of the Bower Birds.

Good housekeeping seal of approval. The tropical family of bowerbirds are famous for complex nests built by males and then decorated with bright and colorful objects to catch the eye of a potential mate. The nest of these birds are actually referred to a “bower.” Usually constructed on the ground, the male will line the approach to the bower with items such as shells, leaves, flowers, feathers, stones, berries, and even discarded garbage, including plastic scraps or bits of glass. Unusually odd items pressed into these decorative displays have included coins and spent rifle shells. This habit of male bowerbirds must rank as the ultimate in trying to impress a mate with shiny bling.

These are just a few of the inventive ways that birds go about attracting and keeping mates. Perhaps you followed some of these tips from our feathered friends to ensure you had a great Valentine’s Day.

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To learn more about birds and other topics from the natural world, friend Stevens on Facebook at https://www.facebook.com/ahoodedwarbler. He is always posting about local birds, wildlife, flowers, insects and much more. If you have a question, wish to make a comment or share a sighting, email ahoodedwarbler@aol.com.

Bird nesting habits are incredibly varied

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Photo by USF&WS                                                A hatchling bird in the safety of its nest.

For most of our birds, the nesting season is winding down. A few species, like Cedar Waxwing and American Goldfinch, are just now starting to think about nesting, but most birds have already finished with the work of ensuring a new generation of their species.

The majority of our common backyard birds build the traditional “cup-shaped” nest that is tucked away in a shrub or the fork of a tree. Birds that build nests in such a fashion include everything from Blue-grey Gnatcatchers and Scarlet Tanagers to Indigo Buntings and American Goldfinches.

 

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Photo by Bryan Stevens                                        A Red-bellied Woodpecker peeks from its nesting cavity.

Other birds, such as Eastern Bluebirds and Tree Swallows, accept human-provided nesting boxes. In the past, however, these birds relied on natural cavities, such as a rotten knothole in a tree’s trunk or a weathered fence post that had gone hollow.

 

The list of these cavity-nesting birds expands to also include Eastern Screech-owl and Great Crested Flycatcher as well as Carolina Chickadee and Tufted Titmouse.

 

Most of the birds I have mentioned so far cannot excavate their own nesting cavities. Some birds, however, are better equipped than others at excavating nesting chambers in everything from tree trunks to river banks. Pileated Woodpeckers, Downy Woodpeckers, Belted Kingfishers and Northern Flickers create their own nesting cavities.

 

Around the world, birds engage in a variety of nest-building strategies.

 

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Male Great Hornbills seal their mates into a nesting chamber until their eggs hatch.

Cavity-nesting offers an added degree of protection compered to an exposed and vulnerable cup nest tucked in a hedge or dense shrub. Some birds have taken cavity-nesting practices to the extreme. For instance, the female Great Hornbill builds her nest in the hollow centers of large tree trunks, and the opening is sealed with a plaster made up mainly of mud, droppings and fruit pulp. She remains imprisoned in her nest until the chicks are semideveloped, relying on the male to bring her food. During this period the female undergoes a complete molt. The young squabs are devoid of feathers and appear very plump. She is fed by her mate through a slit in the seal. The clutch consists of one or two eggs she incubates for 38-40 days. Once the female emerges out of the nest, it is sealed again by the chicks. In some hornbill species, the young depart with their mother, and are tended outside of the former nesting cavity by both parents. The Great Hornbill resides in the forests of India, the Malay Peninsula and Sumatra, Indonesia. There are about 55 species in the hornbill family, which ranges through Africa, Asia and some of the islands of Melanesia.

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Megapodes lay eggs in large mounds, trusting environmental temperatures to incubate them.

Megapodes — also known as “incubator birds” or “moundbuilders” — do not incubate their eggs with their body heat as other birds do, but bury them. Their eggs are unique in having a large yolk, making up 50-70 percent of the weight of the egg. They are best known for building massive nest-mounds of decaying vegetation, which the male attends, adding or removing litter to regulate the internal heat while the eggs hatch. This method of incubation is something practiced by some reptiles, including crocodiles and alligators, but it is definitely unusual among birds. Once hatched, young birds are fully feathered and active, already able to fly and live without any care or assistance from their parents. Two of the better-known species, both from Australia, are the Malleefowl and the Australian Brush-turkey. There are about 20 species of birds classified as Megapodes, and they are concentrated in the Australasian region, including islands in the western Pacific, Australia, New Guinea and the islands of Indonesia. They also occur on the Andaman and Nicobar Islands in the Bay of Bengal.

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Photo by USF&WS                                                              White Terns build no nest, merely laying their egg on a branch or, in this case, on a railing.

The White Tern is a small seabird found across the tropical oceans of the world. Although other terns build nests, the White Tern no longer bothers to construct even a rudimentary nest. Instead, the female lays a single egg on bare branches or in a small fork in a tree. Nothing else is added to the location where the egg is deposited. The behavior is not typical of other terns, which generally nest on the ground and construct the nest of such materials as shells and other seashore debris. Of course, both the eggs and chicks of White Terns are vulnerable to becoming dislodged by heavy winds. Newly-hatched chicks have well developed feet to hang on to their precarious nesting site with.

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Photo by USF&WS              Albatrosses, such as these Laysan Albatrosses, nest in communal colonies. Other birds, such as the Sociable Weaver, also nest in communal conditions.

The sparrow-sized Sociable Weaver (Philetairus socius) of Africa enjoys company, which explains how such a small bird constructs a huge nest. Actually, many of these birds working together construct a huge structure — sometimes described as similar to a bale of hay — that hangs from sturdy trees and other tall structures. Such a “compound nest” is rather rare among birds. The communal nests built by Sociable Weavers can house 100 pairs of birds and are quite spectacular. They are also considered the largest bird-built structures in the world. Other birds also benefit from these huge structures, which are built mostly of grass and sticks. Other small birds may also nest or roost in the structure, and large birds, such as vultures, have been known to build their own nests on top of these compound nests. Other species of weavers also build communal nests, but their efforts are not quite as impressive as those constructed by the Sociable Weaver.

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Photo by USF&WS A colony of nesting albatrosses consists of individuals able to tolerate very defined senses of personal space.

The most unusual nest I’ve observed personally was that of a Killdeer built in the parking lot of a local mobile home dealership. The Killdeer is a type of plover, a family of birds belonging to the group known as shorebirds. The female Killdeer will locate a shallow depression on the ground that can be lined with grass, weeds, bark, shells or rocks to form a crude nest. The Killdeer will apparently make use of any material readily available to line their nests. The particular Killdeer nesting in the gravel parking lot of the mobile home dealership had collected discarded cigarette butts to line her nest, which contained the usual four eggs. Her efforts are a testament to the ingenuity of some of our feathered friends. As far as I know, her nest succeeded, and she and her mate reared four young Killdeer. I always joke when telling this story that the young birds may have been born with a nicotine addiction.