About swallow nest, swiftlet, edible bird’s nest

Swallow Houses

naturesvilla.com
Barn Swallows breed from Alaska across Canada, throughout the United States, and south through central Mexico. With the proliferation of human-provided nesting sites, the North American Barn Swallow population has increased in most places during the 20th century. Numbers are especially up in the central and eastern United States. Barn Swallows show strong fidelity to their natal site, most nesting within 20 miles of their birthplace and some much closer. Members of a pair typically stay together to raise a second brood and return in successive years to the same nest site. If you have the right habitat, barn swallows are easy to attract. A simple nesting perch may be placed under the eaves, inside a garage or barn, or on the side of a building.

Tree Swallows are found all across the continental United States and Canada, and in parts of Alaska, as far north as cavities are available, avoiding only the southeastern corner of the U.S. Tree Swallows prefer open habitats, such as the edges of woods, and areas near water, including marshes, shorelines and swamps. Tree Swallows are quite tolerant of humans. Nesting is quite synchronous in Tree Swallows; that is, females tend to begin nesting within a week or 10 days, usually in April, of their neighbors. Tree Swallows nest in natural tree cavities, woodpecker holes and nest boxes. Tree Swallow houses should be placed 5 to 15 feet high on a post or tree in open areas. They should be spaced 30 to 100 feet apart with the entrance hole facing east.

Violet-green Swallows are found from the Rocky Mountains west to the Pacific coast. Their range spans from central Alaska and central Canada south to the Mexico’s highlands. Violet-green Swallows prefer open, deciduous, or mixed coniferous-deciduous forests containing ponderosa pine, aspen, willow and spruce trees. In the northern part of its range, this species breeds at lower elevations on the coast and in wooded canyons. In the southern part of their range, they breed at higher elevations (2,000 to 3,000 meters). Violet-green Swallows nest in cliff crevices, natural tree cavities, woodpecker holes, in old nests of Banks and Cliff Swallow, under the eaves of buildings, and in nest boxes. They can nest in close association with Cliff Swallows, Tree Swallows, White-throated Swifts, and Western Bluebirds. One report documented a pair of Violet-greens assisting a pair of Western Bluebirds in raising young. The swallows guarded the nest and tended the bluebird nestlings, and after the bluebirds fledged, the swallows used the nest site. In the northern portion of their range, pair formation begins in mid-April and breeding begins in late May. In the southern portion, breeding begins in early May. Violet-green Swallow houses should be placed 9 to 15 feet high in open or broken deciduous or mixed deciduous-coniferous forests, wooded canyons, or edges of dense forests.

Barn Swallows show strong fidelity to their natal site, most nesting within 20 miles of their birthplace and some much closer. Members of a pair typically stay together to raise a second brood and return in successive years to the same nest site. Barn Swallows prefer an open-front nesting box. This nesting perch may be placed under the eaves, inside a garage or barn, or on the side of a building. It offers protection from elements and requires no maintenance.

Swallows and Swifts - aerial feeders

wildwatch.com
by Duncan Butchart

Although swallows and swifts are superficially similar in appearance, and often pose identification problems for beginners, they are actually unrelated. Scientists have not yet determined the closest relatives of the swallows (which include the martins), but they belong to a large assemblage of passerine birds including warblers and larks. Swifts, on the other hand, are related to the New World hummingbirds (with which they share similar wing bone structures) although the ancestry is ancient.

CONVERGENT EVOLUTION

The fact that swallows and swifts have more similar body shapes to one another than they do to their close relatives, is a result of convergent evolution. Both groups of birds are specialized aerial feeders of tiny invertebrates and have long pointed wings which allow them superb maneuverability. Interestingly, the nocturnal nightjars, which are considerably larger but also feed on airborne insects, have a wing to body shape ratio very similar to the swallows and swifts. All these birds catch their prey by keeping their mouths open as they fly through the air.

HARBINGERS OF SPRING… OR AUTUMN

In Africa, there are 22 species of swift in 8 genera, and 38 species of swallow and martin in 7 genera. The best known of all the swallows is undoubtedly the Barn Swallow (which was known as the ‘European Swallow’ until recently). This bird has a vast cosmopolitan range, occurring on every continent except Antarctica. In Africa, these familiar birds are primarily n n-breeding visitors from Europe where - in places such as the England and Holland - they breed mostly on man-made structures and their seasonal return sees them as harbingers of Spring. In sub-Saharan Africa, large flocks of these swallows roost in reedbeds at night where they are vulnerable to capture by people, and this mass-predation is proving to be of increasing conservation concern. Each April, in anticipation of cooler and shorter days in southern Africa, huge numbers of Barn Swallows can be seen aggregating on overhead wires as flocks prepare for their 10 000km journey back to Europe. Like other migratory birds, the effects of global warming are already showing signs of influencing their seasonal movements.

NESTS OF MUD AND STRAW

All swallows build cup-shaped nests from mud pellets and straw, and often situate the structure in the shade of a roof awning, bridge or some other sheltered spot. Most species of swallow and martin are gregarious and in Africa, it is not uncommon to see several species foraging together. The South African Cliff Swallow and Grey-rumped Swallow breed colonially, but most of the other species nest alone. Among the more commonly encountered swallows in southern and east Africa are the Wire-tailed Swallow which is always found close to water, and the Lesser Striped Swallow which often nests on houses and other buildings. The Blue Swallow is an endangered species dependent upon high-altitude grasslands which - especially in South Africa - have shrunk in the face of expanding timber plantations.
LIVING WITH MANKIND

In contrast to the often colorful swallows, the swifts are more difficult to separate. Most are predominantly black in colour, with or without white rumps and throats. Over much of Africa, the Little Swift and White-rumped Swift are the most frequently encountered species, although the Common Swift which is a non-breeding visitor during the southern summer can be locally abundant. These and other species frequently nest under bridges or on the sides of city skyscrapers. With its white belly, the large Alpine Swift is a distinctive species in mountainous regions. The African Palm Swift is pale brown in colour and even more slender and elongated than other swifts; it breeds only among the dry leaves of palm trees and has expanded its range into places like Johannesburg where these trees are commonly cultivated.

KEY DIFFERENCES BETWEEN SWALLOWS AND SWIFTS

There are several key differences between swallows and swifts. Swifts generally have narrower, sickle-shaped wings and do not perch between foraging flights (in fact, their extremely short legs and toe structure does not allow them to perch at all and they can only cling to rough surfaces!). Not only do swifts capture all their food in flight, but these remarkable birds sometimes even sleep and mate in the air! Swallows tend to fly closer to the ground than swifts and have distinctly broader wings. Many species have long forked tails ending in thin streamers which grow to a maximum length during the breeding season, but the martins typically have shorter squared-off tails.

A CHALLENGE FOR BIRDWATCHERS

Although swifts and swallows pose an identification challenge for beginner birdwatchers (and are often ignored by experienced ones!), they are fascinating birds whose existence is closely tied to that of mankind.

- Duncan Butchart -

 

 

Add comment September 18th, 2006

Swifts and Swallows

.theava.com
by Rob Lee

Whether the Giants are winning games in big fistfuls, or can’t produce as much offense as a foul-mouthed grandmother, there’s always a good reason to go to their ballpark. I’m not talking about the starlings foraging in the outfield grass, or the hordes of Western gulls that begin gathering faithfully during the seventh-inning stretch (although the best seats for my proposed entertainment are in the upper deck, with the gulls).

I’m speaking of the barn swallow and the white-throated swift, foraging on all those beer-crazed bugs rising off the crowd. While these birds are seemingly quite similar — long, swept-back wings, the aerodynamics of great fliers — the swallow is a song bird and the swift is not; actually more closely related to hummingbirds.

Sitting high in this bird observation platform, formerly known as the Giants’ home, you’ll notice that the two birds have different flying techniques. The swallow cuts a graceful, complicated swath through the air, constantly maneuvering to pick off one insect after another, while the swift is just that; flashing under the stadium lights like a jet, using a few quick, powerful strokes of its wings and then a short glide, eating the tiny insects — “aerial plankton” — in its path.

The white-throated swift may be the fastest bird in North America, once estimated to have fled a swooping falcon at more than 200 mph. It could easily keep pace with, inspect and then pass a soaring Barry Bonds homer. Both of these birds have wings “built for speed,” but the swallow has slender, flexible wing bones suitable for its elegant flight, while the swift has shorter, more massive bones (and long primary feathers), with which it can achieve the stiff, superfast wing beats that give it surpassing speed.

Swallows typically fly lower to the ground, pursuing insects (their hard work providing a very nutritious diet), while swifts fly high, on a line, and much longer distances, hunting for clouds of anthropoids to charge through repeatedly. While the swift’s flight uses less energy, it also yields less nutrition in the types of insects caught. (Swifts typically fly more than 500 miles a day, and, as they are long-lived for small birds — larger swifts may live more than 20 years — well over a million miles in their lifetime.)

Both birds do nearly everything in flight, including drinking, bathing, courting, and, among swifts, copulating. Some swifts, after mounting high in the sky, are even thought to sleep in flight.

Flying is so central to the lives of these birds that the swallow can only walk with difficulty and the swift can’t walk at all. Swallows have tiny, weak legs and feet that only allow perching on such things as wires or thin twigs. Swifts’ legs are virtually nonexistent, but they have tiny, strongly clawed feet, all four toes facing forward, with which they can hang on vertical surfaces, such as cliffs or buildings.

Barn swallows are a really lovely bird, artistically colored in blue, rust and buff with a long swallowtail, while the swift is basic black and white.

Barn swallows raise four to five chicks in their mud-and-grass cup nest, usually affixed under the eaves of a building or beneath a bridge. (These swallows have used human structures for nesting so widely, and for so long, their natural sites are virtually forgotten.) White-throated swifts raise a similar brood in very inaccessible crevices in cliffs, and sometimes buildings. Gathering twigs on the wing from dead trees, they build a cup nest, which they cement in place, and together, with saliva.

The close proximity to people with which these swallows consistently nest makes them one of the easiest nesting birds to observe, while this swift is just the opposite, with relatively little known about its nesting behaviors.

Both birds migrate, but the white-throated swift doesn’t go very far, usually not beyond the Southwest. The barn swallow is a champion long-distance migrator, some birds going 7,000 miles each way. Both of these species are social, usually found in small to large flocks, although the individuals I saw at the ballpark were alone.

I can’t promise the birds will show up when you go to a game, but if they do, it will be a joy to watch their two styles of mastery above the crowd, the two species, in a way, mirroring the combination of relaxation and intensity that characterizes baseball.

Add comment September 18th, 2006