Archive for February, 2007
Yoshihiro UCHIDA, Yoji TSUKADA and Tsunetake SUGIMORI
oxfordjournals.org
Kyoto Research Laboratories, Marukin Shoyu Co., Ltd. Uji, Kyoto 611
Japanese Biochemical Society
Neuraminidase [sialidase, EC 3.2.1.18 [EC] ] was found to be widely distributed in bacteria belonging to Arthrobacter. Among these bacteria, Arthrobacter ureafaciens, A. oxydans, and A. aurescens produced relatively potent neuraminidase activities. For the production of this enzyme, not only colominic acid, a homopolymer of N-acetylneuraminic acid, but also N-acetylneuraminic acid, the reaction product of this enzyme, are effective as sources of carbon.
An affinity adsorbent specific for neuraminidase was prepared by cross-linking colominic acid with soluble starch by means of epichlorohydrin. Neuraminidase from A. ureafaciens could be purified on this affinity column. The purified neuraminidase was shown to be free from protease, N-acetylneuraminic acid aldolase, phospholipase C, and glycosidases.
Aminoff’s assay procedure for sialic acid was modified to avoid the centrifugation step. The modified procedure gave a higher molecular extinction coefficient.
1A part of this paper was presented at the Annual Meeting of the Agricultural Chemical Society of Japan, Kyoto, April 1976.
February 26th, 2007
ncbi.nlm.nih.gov
• Brown CR,
• Brown MB.
Department of Biological Sciences, University of Tulsa
How colonial animals space their nests in relation to conspecifics may provide clues as to whether coloniality provides net benefits or occurs only because breeding sites are limited. We examined how nearest-neighbour distance varied in relation to settlement time in the highly colonial cliff swallow, Petrochelidon pyrrhonota, comparing observed nearest-neighbour distances to those expected if birds spread out to maximize nest spacing. Cliff swallows generally settled closer to each other than required by the available substrate, and clustered their nests closer in large colonies than in small ones. The first settlers at a colony site spaced themselves further apart than later arrivals but did not maximize nearest-neighbour distances. The first arrivals maintained greater nest spacing throughout the season than did birds that arrived later. Colony size and amount of nesting substrate had no effect on initial settlement distances of the first arrivals, but eventual nearest-neighbour distances declined with colony size. First arrivals may gain less from nesting with conspecifics and thus are less likely to cluster their nests than later arrivals, which may often be young or naive birds that gain more from the social benefits of colonial nesting. The results are consistent with the presumed social advantages cliff swallows receive from coloniality and do not support the hypothesis that colonies result from nesting site limitation. Copyright 2000 The Association for the Study of Animal Behaviour.
PMID: 10640366 [PubMed - as supplied by publisher]
February 23rd, 2007
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.
February 22nd, 2007
associatedcontent.com
By D. Miller
The barn swallow, or Hirundo rustica, is an amazing bird to watch. These little birds travel a long distance in their six to eight years of life. These birds are found all over the world, except for Australia. The interesting thing about barn swallows is that they nest in large colonies. If you live near an open field or on the countryside, chances are you can easily attract these amazing birds. We have barn swallows that nest on our front porch every year. Watching these birds is a true delight.
Barn swallows differ from the American swallow because the barn swallow has a tail that is deeply forked. A male barn swallow will have longer tails than the female, and both male and female have rust on the underside of their body, a tiny bill and dark, almost blue upperparts. An adult barn swallow will reach about six inches in length. Young barn swallows look very similar to the adult bird, but are often paler and have a short tail.Â
When barn swallows nest, they stay near their colony. If you have ever hosted barn swallows, you will know they are near. If you walk near the carefully constructed nest, the entire colony of birds, which are excellent at flying in sharp turns, will attempt to mob you. Often, these attractive and skilled birds will nest very near humans, often on the eves of porches or in barns, as their name suggests. This is because barn swallows prefer to eat bugs. They can eat a large amount of flies, beetles, bees, moths, mayflies, grasshoppers, and aphids. These birds are quite beneficial to humans. These birds often begin their hunt for insects late on warm summer afternoons. They fly close to the ground over fields and water. They carry the insects back to their young.Â
Barn swallows are also easy to identify because of their unique nest they build for their young. Both male and female will make several hundred trips to collect bits of mud pellets and plant fibers. Both the male and female barn swallow works to construct the nest. These nests are almost cylinder in shape and resemble a carefully woven basket of mud. After the nest is complete, the female bird lays between three and five eggs. The female bird has what is called a brood patch, which is a bare part of her underside to enable her to incubate her eggs. These feathers grow back. Barn swallow eggs will hatch in about 15 days and the young will leave the nest after about 18 to 24 days. In addition, the male and female barn swallow may choose to use the same nest to raise another brood within the same mating season.Â
Watching the barn swallows take care of their young is fascinating. The parent birds work tirelessly around the clock to hunt insects and carry them back to the waiting young. At night, the parent birds rest outside of the nest, often clutching to the eve of the porch so that the young has the entire nest.Â
February 21st, 2007
news.cornell.edu/
By Roger Segelken
Earlier springs with warmer temperatures over the past 30 years have prompted a ubiquitous North American bird species, tree swallows, to begin laying eggs, on average, a week or more earlier. But whether these harbingers of global warming are being adversely affected by changing weather patterns isn’t clear, biologists in New York, Wisconsin and California report in Proceedings of the National Academy of Science (PNAS).
When tree swallows start earlier, they often lay more eggs, say the biologists, referring to data collected by thousands of volunteer citizen-scientists who have watched the birds’ nest boxes for 40 years.
“We don’t know whether earlier lay dates and larger clutch sizes will be good in the long term for populations of tree swallows,” said David W. Winkler, a Cornell professor of ecology and evolutionary biology. “And tree swallows are just one of the many organisms that potentially can be affected by climate change.”
After an exhaustive, three-year statistical analysis of bird and weather data, Winkler, Peter O. Dunn of the University of Wisconsin-Milwaukee and Charles E. McCulloch, a biostatistician at the University of California-San Francisco, report the effects of climate change on swallows in the PNAS Online Early Edition, week of Sept. 23, 2002. Their article is titled “Predicting the effects of climate change on avian life history traits.”
Tree swallows (Tachycineta bicolor) are astute weather monitors, Winkler explains, because of three characteristics:
They are aerial insectivores, hunting the insects they crave “on the wing.” (An adult tree swallow can capture as many as 50 insects before returning to the nest and feeding its young.)
Tree swallows are “income breeders” that rely, more than many other species, on their daily foraging intake — both before and during the spring breeding season. (Tree swallows begin breeding once their source of insect income looks large enough, but the future of their growing family is at the mercy of sometimes-fickle weather.)
Insects the swallows need do not fly during cool weather, and swallows will not forage on the ground. (A sudden cold snap and a local shortage of insects can kill 5- to 8-day-old nestlings before their developing bodies learn to thermoregulate and grow insulating feathers. When adult tree swallows are forced by cool weather to travel greater distances in search of insects, they may be forced to abandon their chicks.)
Professional ornithologists rely on trained amateurs in volunteer programs, such as the Cornell Lab of Ornithology’s Nest Record Card Program, to report on birds throughout a wide geographic area. In 1999, after studying 21,000 nest records from Cornell’s database and similar programs in Canada, Dunn and Winkler reported that the lay date of tree swallows shifted an average of nine days earlier between 1959 and 1991.
Since that report, which was among the first to link animal-behavior changes to global warming, Winkler and Dunn have worked with McCulloch and extended the analysis to another key life-history trait — the number of eggs birds lay each year.
“One of the strongest patterns in this data set showed birds that begin earlier in a given season tend to lay larger clutches of eggs,” Winkler recalled. “We wanted to see if earlier average lay dates over the past 30 years have led to larger clutches. However, it is interesting to find that, despite the change in lay dates, there has been no significant increase in clutch size across the years.”
To say more with any certainty will require a much better understanding of how birds respond to climate change — and more detailed, hands-on research than even the most dedicated legions of volunteers can conduct. Nevertheless, the PNAS authors believe that their statistical analysis of tree swallows’ response can be a template for studies by other researchers of how climate change might affect various plant and animal species.
“Tree swallows are doing a fine job of observing seasonal climate conditions and responding in a way that’s easy for us to measure,” Winkler noted. “Clearly, they’re laying eggs earlier on average. Our job as biologists is to learn more about the birds and their food organisms in order to understand the effects of this and other responses to climate change.”
The study was sponsored, in part, by the National Science Foundation and Cornell.
February 20th, 2007
Learn the Important Features of a Nesting Box That Will Attract Nesting Birds to Your Yard
© Rosemary Drisdelle
A nesting box has to be right for the bird. Choose a local bird, check box dimensions, hole size and position, and select an appropriate location for a perfect fit.
In the spring, a bird’s thoughts turn to nesting; you can help the birds and improve your backyard bird habitat by providing a bird house, or nesting box. Don’t just hang any old box with a hole in it up in a tree, however: you’ll need to place the right kind of nesting box, for the right kind of bird, in the right place. Birds can be fussy about bird house design; if you want the Yellow-shafted Flicker that hunts ants on your lawn to nest in your trees, a nest box designed for Black-capped Chickadees isn’t going to work.
First, choose the right bird. What birds frequent feeders or other food sources on your property? The birds that already visit are the ones most likely to check into a nesting box. If you want to attract new birds to your property, think about the geography nearby: if you have a lake within 3.25 km (2 miles) of your home, putting up Tree Swallow nesting boxes might bring them.
Next, choose the right nesting box plan. If you’re going to build your own, there are lots of free wild bird house designs available on the internet. Just search for “blue bird nesting box,” “owl nesting box,” or whatever is appropriate for you. It’s a good idea to look at several different plans to be sure you are getting the dimensions and other details right. Pay specific attention to what the floor dimensions and height should be. Another important detail is where to put the hole and how big to make it. Holes that are too large allow predators to enter the nest and prey on eggs and young.
Other small design details may make the difference between an occupied nesting box and a vacant one. Northern Flickers like to excavate their own nesting site, so placing a block of partially rotted wood in the box may entice them. Nuthatches like nest boxes that are sheathed with tree bark. A Purple Martin nesting box should be white.
Finally, give careful thought to where you place the nesting box. How far off the ground should it be? A Chickadee nest box should be 1.25 - 2.5m (4 - 8 ft) high. For Eastern Bluebirds, place the box between 1.5 - 3m (5 - 10 ft) off the ground. A Northern Flicker box can be placed outside a second story window - 6m (20 ft) up! Consider the surroundings too: does your bird nest in thickets, or prefer open spaces? Should the bird house be attached to a tree trunk, or hung from a branch? Whether you purchased your nesting box or built one from a plan, check the instructions for placement hints.
Here are two last thoughts (one for the tree and one for the birdwatcher). Try to do minimal damage to the tree when you attach your nesting box. Don’t wrap bands around the trunk that will restrict growth, and if you attach the box with screws, use the smallest screws that will hold the house securely in position. Finally, try to find a good location where you can see the nest box and enjoy any traffic coming and going. If birds take up your invitation, your wild bird house will be a delightful focus of attention in the spring. Happy nesting.
February 19th, 2007
eurekalert.org
ITHACA, N.Y. — Even after they have paired with a male, the female North American barn swallow still comparison-shops for sexual partners. And forget personality; the females judge males by their looks — the reddish color of the males’ breast and belly feathers.
If the male’s red breast is not as dark as other males in the population, the female is more likely to leave him and then secretly copulate with another male, according to a Cornell University study featured on the cover of the journal Science (Sept. 30, 2005).
“The bad news for male swallows is the mating game is never over,” said lead author Rebecca Safran, who conducted the study while a Cornell postdoctoral researcher in ecology and evolutionary biology, and in the Cornell Laboratory of Ornithology. “It is dynamic and continual. This is something that most humans can relate to — think of how much time and money we spend on our looks and status long after we have established stable relationships.”
Barn swallow (Hirundo rustica erythrogaster ) males have a wash of reddish-chestnut color from their throats to their bellies, and this color varies among birds from very pale red-brown to a dark rusty-red. Like many songbirds, half of all male barn swallows typically care for at least one young chick that was actually fathered by another bird. The researchers used this widespread phenomenon of cheating to test the factors that may keep a female barn swallow faithful to her mate. Sometimes males even rear an entire nest of illegitimate young.
After all pairs had laid their first set of eggs, Safran removed the eggs so that the females would mate again. Before the females chose their mates for their second nest, Safran captured the males and randomly assigned them to one of three treatments. She either painted their throats, breast and belly feathers with a red marker to enhance their feathers to match the darkest — and most attractive — males in the population, or left them alone or painted them with a clear marker to ensure that results were not biased by the coloring process. Then she let the pairs breed again. She conducted comparative DNA tests on the offspring from the first and second nests.
In the research, all 30 females remained socially paired with their original male mate, but they were sexually active with other males. The males with enhanced color fathered a substantially larger percentage of offspring in their second nests. Males whose color was unchanged fathered the same number or fewer chicks than they had in their first nests. “The study shows that the females are paying close attention to these signals and that they respond quickly to changes in their mate’s appearance,” said Safran.
The reddish breast and belly feathers indicate a male’s quality, such as his health, status or ability to raise young, Safran speculates.
The actual cue that female barn swallows use to assess potential mates differ according to regional tastes. For example, classic studies have shown that in the very closely related European barn swallow (H. rustica rustica) , males with long tail feathers attract more mates. Although many previous studies have investigated mating patterns in birds and other animals, this is the first study of its kind to meticulously rule out biases such as age, size and initial variation in signals of male quality, like coloration, and to demonstrate that mate-selection decisions are continual and dynamic. The results of the study have implications for the evolution and upkeep of showy ornamental traits — such as a peacock’s tail or a deer’s antlers — that are costly for males to maintain but give them an edge over rival males. “If females are assessing mates on a day-to-day basis, it explains why males continue to maintain costly ornaments even when they might appear to have served their purpose,” said co-author Irby Lovette, assistant professor and director of the Cornell Lab of Ornithology’s Evolutionary Biology program.
“Our goal is now to understand how certain males keep a better plumage than others,” said Kevin McGraw, Cornell Ph.D. ‘03, one of the co-authors who is now an assistant professor at Arizona State University in Tempe. “Factors like ultraviolet radiation from the sun, soiling and even feather degrading bacteria are known to affect the color of bird feathers once they are grown, and perhaps the best males are those who spend more time preening and protecting their plumage.”
The paper’s other co-author is Colby Neuman, Cornell B.S. ‘05. In early September, Safran began a new position as a postdoctoral researcher at Princeton University. Supporters of the study included: the National Science Foundation, the American Association of University Women, the American Ornithologists’ Union and the Animal Behavior Society.
February 16th, 2007
biologynews.net
Even after they have paired with a male, the female North American barn swallow still comparison-shops for sexual partners. And forget personality; the females judge males by their looks — the reddish color of the males’ breast and belly feathers.
If the male’s red breast is not as dark as other males in the population, the female is more likely to leave him and then secretly copulate with another male, according to a Cornell University study featured on the cover of the journal Science (Sept. 30, 2005).
“The bad news for male swallows is the mating game is never over,” said lead author Rebecca Safran, who conducted the study while a Cornell postdoctoral researcher in ecology and evolutionary biology, and in the Cornell Laboratory of Ornithology. “It is dynamic and continual. This is something that most humans can relate to — think of how much time and money we spend on our looks and status long after we have established stable relationships.”
Barn swallow (Hirundo rustica erythrogaster ) males have a wash of reddish-chestnut color from their throats to their bellies, and this color varies among birds from very pale red-brown to a dark rusty-red. Like many songbirds, half of all male barn swallows typically care for at least one young chick that was actually fathered by another bird. The researchers used this widespread phenomenon of cheating to test the factors that may keep a female barn swallow faithful to her mate. Sometimes males even rear an entire nest of illegitimate young.
After all pairs had laid their first set of eggs, Safran removed the eggs so that the females would mate again. Before the females chose their mates for their second nest, Safran captured the males and randomly assigned them to one of three treatments. She either painted their throats, breast and belly feathers with a red marker to enhance their feathers to match the darkest — and most attractive — males in the population, or left them alone or painted them with a clear marker to ensure that results were not biased by the coloring process. Then she let the pairs breed again. She conducted comparative DNA tests on the offspring from the first and second nests.
In the research, all 30 females remained socially paired with their original male mate, but they were sexually active with other males. The males with enhanced color fathered a substantially larger percentage of offspring in their second nests. Males whose color was unchanged fathered the same number or fewer chicks than they had in their first nests. “The study shows that the females are paying close attention to these signals and that they respond quickly to changes in their mate’s appearance,” said Safran.
The reddish breast and belly feathers indicate a male’s quality, such as his health, status or ability to raise young, Safran speculates.
The actual cue that female barn swallows use to assess potential mates differ according to regional tastes. For example, classic studies have shown that in the very closely related European barn swallow (H. rustica rustica) , males with long tail feathers attract more mates. Although many previous studies have investigated mating patterns in birds and other animals, this is the first study of its kind to meticulously rule out biases such as age, size and initial variation in signals of male quality, like coloration, and to demonstrate that mate-selection decisions are continual and dynamic. The results of the study have implications for the evolution and upkeep of showy ornamental traits — such as a peacock’s tail or a deer’s antlers — that are costly for males to maintain but give them an edge over rival males. “If females are assessing mates on a day-to-day basis, it explains why males continue to maintain costly ornaments even when they might appear to have served their purpose,” said co-author Irby Lovette, assistant professor and director of the Cornell Lab of Ornithology’s Evolutionary Biology program.
“Our goal is now to understand how certain males keep a better plumage than others,” said Kevin McGraw, Cornell Ph.D. ‘03, one of the co-authors who is now an assistant professor at Arizona State University in Tempe. “Factors like ultraviolet radiation from the sun, soiling and even feather degrading bacteria are known to affect the color of bird feathers once they are grown, and perhaps the best males are those who spend more time preening and protecting their plumage.”
The paper’s other co-author is Colby Neuman, Cornell B.S. ‘05. In early September, Safran began a new position as a postdoctoral researcher at Princeton University. Supporters of the study included: the National Science Foundation, the American Association of University Women, the American Ornithologists’ Union and the Animal Behavior Society.
Source : Cornell University News Service
February 15th, 2007
birdnature.com
“There swims no goose so gray, but soon or late,
She takes some honest gander for a mate;”
There live no birds, however bright or plain,
But rear a brood to take their place again. — C. C. M.
QUITE the jolliest season of the year, with the birds, is when they begin to require a home, either as a shelter from the weather, a defense against their enemies, or a place to rear and protect their young. May is not the only month in which they build their nests, some of our favorites, indeed, waiting till June, and even July; but as it is the time of the year when a general awakening to life and activity is felt in all nature, and the early migrants have come back, not to re-visit, but to re- establish their temporarily deserted homes, we naturally fix upon the first real spring month as the one in which their little hearts are filled with titillations of joy and anticipation.
In May, when the trees have put on their fullest dress of green, and the little nests are hidden from all curious eyes, if we could look quite through the waving branches and rustling leaves, we should behold the little mothers sitting upon their tiny eggs in patient happiness, or feeding their young broods, not yet able to flutter away; while in the leafy month of June, when Nature is perfect in mature beauty, the young may everywhere be seen gracefully imitating the parent birds, whose sole purpose in life seems to be the fulfillment of the admonition to care well for one’s own.
There can hardly be a higher pleasure than to watch the nest-building of birds. See the Wren looking for a convenient cavity in ivy-covered walls, under eaves, or among the thickly growing branches of fir trees, the tiny creature singing with cheerful voice all day long. Observe the Woodpecker tunneling his nest in the limb of a lofty tree, his pickax-like beak finding no difficulty in making its way through the decayed wood, the sound of his pounding, however, accompanied by his shrill whistle, echoing through the grove.
But the nest of the Jay: Who can find it? Although a constant prowler about the nests of other birds, he is so wary and secretive that his little home is usually found only by accident. And the Swallow: “He is the bird of return,” Michelet prettily says of him. If you will only treat him kindly, says Ruskin, year after year, he comes back to the same niche, and to the same hearth, for his nest. To the same niche! Think of this a little, as if you heard of it for the first time.
But nesting-time with the birds is one of sentiment as well as of industry. The amount of affectation in lovemaking they are capable of is simply ludicrous. The British Sparrow which, like the poor, we have with us always, is a much more interesting bird in this and other respects than we commonly give him credit for. It is because we see him every day, at the back door,, under the eaves, in the street, in the parks, that we are indifferent to him. Were be of brighter plumage, brilliant as the Bobolink or the Oriole, be would be a welcome, though a perpetual, guest, and we would not, perhaps, seek legislative action for his extermination. If he did not drive away Bluebirds, whose nesting-time and nesting-place are quite the same as his own, we might not discourage his nesting proclivity, although we cannot help recognizing his cheerful chirp with generous crumbs when the snow has covered all the earth and left him desolate.
C. C. MARBLE.
February 14th, 2007
borealforest.org
Description
Distinguishing Features - Back and head, shiny steel blue with greenish reflections. under parts and throat, white. Bill, black. Tail, forked. Female slightly smaller and somewhat duller in colouration.
Size - 12.5 - 15.7 cm (5 - 6.25 in).
Habitat
Around waterways, marshes and beaver ponds.
Nesting
In a tree cavity or old woodpecker hole; crevice in a building or a bird house. Nest is made up of grasses, lined with feathers and down. Eggs, 4 - 6; white. Incubation period 13 - 16 days.
Notes
The Tree Swallow lives primarily on a diet of insects. This agile flier is often observed flying swiftly over water catching flying insects.
February 13th, 2007
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