Archive for May, 2007
Minneapolis Star Tribune (subscription), MN - May 29, 2007
On The Wing Jim Williams
Last update: May 30, 2007 – 8:25 AM
A cloud of cliff swallows swirls 100 yards ahead of my van, flying above the road that bisects flat pasture in eastern South Dakota.
The birds appear on one side of the road, swoop up, perform dogfight maneuvers, then disappear on the other side of the road.
Most North American bird species have been affected by humans one way or another, some for the better, others for the worse. A species that has benefited significantly from the efforts of man — efforts never intended to involve birds at all — is the cliff swallow.
These birds, which were thought to have been limited to the southwestern United States up to 150 years ago, now breed almost everywhere in North America.
What did we do to help this species spread across the continent? We built bridges and culverts and buildings. Those structures meet the site requirements that cliff swallows have for their mud nests.
When they choose a nesting site, cliff swallows look for a horizontal overhang intersecting a vertical face. They require that the intersection form an angle close to 90 degrees. Because 90 degrees is one of our basic construction angles, many of our roadway structures suit the birds nicely.
Nest builders
Cliff swallows nest in gourdlike structures made of mud. As soon as the spring migration is over, groups of cliff swallows search for a nesting site. Once a site has been found, individual males choose where to build their nests.
The first nests begin at that critical right angle. Other nests are attached to those first nests, and eventually there may be hundreds of nests stuck together at one site. The nest entry begins as a hole, then evolves into a tunnel as as the nesting season progresses.
Cliff swallows require mud for construction, and will fly miles to find it. A pair of birds with good access to mud can deliver as many as 44 mud pellets to the construction site in 30 minutes. The average nest contains from 900 to 1,200 pellets, so sharing walls with a neighbor cuts construction time.
Cliff swallow nests, which are snug and often virtually predator-proof, sometimes are used by other bird species, including house wrens, house finches, house sparrows and Eastern bluebirds.
You’ve probably encountered cliff swallows before. Maybe you’ve driven across a river on a concrete bridge and found the air filled with swooping swallows. Or, perhaps you’ve passed a creekbed culvert in one of the prairie states and the birds have taken to the air as you rumble across it.
The next time you see them, stop to watch these builder birds.
Jim Williams, a lifelong birder, serves as a member of the U.S. National Wildlife Refuge Birding Initiative Committee. He also is a member of the American Birding Association, Ducks Unlimited, Pheasants Forever and Delta Waterfowl. He can be reached by e-mail at two-jays@att.net.
May 31st, 2007
ebnresources.diytrade.com
On the left is a map indicating countries producing the edible type white bird’s nest (Click on Map for a larger picture) The history of bird’s nest consumption can be traced back to China nearly 1,500 years ago during the Tang Dynasty period (A.D. 618-907
It was believed that bird’s nest had been brought back from ‘Nan yang’ (the southern countries), by sea-faring Chinese sailors, and introduced to the courts of the China’s Emperor as a supreme delicacy (food of the Emperor). During that era, only the family of the Emperor and his court officials has the privilege of consuming the highly priced bird’s nest. It was only at the end of the Emperor rule, that the common people were introduced to bird’s nest and the value and demand for bird’s nest has since continued to climb due to its rarity and nutritional properties. Nowadays, the primary target for this product is the Chinese community around the world, with Hong Kong, Mainland China and Taiwan the top consumers followed by Singapore, U.S, Middle East countries and others. Bird’s Nest soup is considered an esteemed cuisine by upper class Chinese families and appreciated for its health benefits, so much so that diners at a certain Hong Kong restaurant are willing to pay almost US$60.00 per bowl for the highest quality bird’s nest soup! Although there is stable demand from the restaurant consumers, the peak season of demand comes during the Chinese New Year period. Gift giving of Bird’s Nest is especially popular during this period as it wishes the recipient good health and longevity of life as well as symbolizing the givers affluence and status in society. Bird’s Nest Soup has been a part of Chinese culture and tradition for hundreds of years. Increasing wealth in the Asian region along with the big increase in price of a bowl of bird’s nest soup has made Swiftlet nests the ‘Caviar of the East’. While it is possible to find substitutes to thicken soup, it will be difficult to take away the allure of Bird’s Nest Soup as a status symbol.
The above is an extract from the Book “Introduction to the Edible Bird’s Nest (of Aerodramus Fuciphagus species) Industry in Asia” written by Adrian Y. which is available at our PRODUCT page.
May 30th, 2007
animalbehavior.org
Posted by Jill Mateo
rom the dept.
Bird wealth is measured in food, not money, and researchers have discovered that berry-rich bluebird young with edible inheritances prefer to stay in the nest.
Since humans and many other animals also often stay close to home when the pickings are good, the discovery supports the theory that wealth can promote family stability and togetherness.The study, which will be published later this year in The Proceedings of the Royal Society B, focused on Western bluebirds, Sialia mexicana, which live in California.While bluebird daughters usually flew away from home at the expected time in August, bluebird sons stayed with their parents all the way through winter when desired mistletoe berries were plentiful.
May 29th, 2007
Erwin Record, TN - May 22, 2007
By Bryan Stevens - Staff Writer
All good things must come to an end.
I saw a female Rose-breasted Grosbeak at my feeders on the morning of Friday, May 11. I haven’t seen any of these birds at the feeders since that date.
I had Rose-breasted Grosbeaks at my feeders for a record-breaking 17 consecutive days this spring. The birds first showed up on April 25. In the past, I felt fortunate if the birds lingered for even a couple of days.
Now, I will remain hopeful for visits during the fall migration.
•••••
Among my favorite returning birds each spring are the warblers. I have enjoyed some incredible sightings of several different warblers in May, including one I haven’t seen in several years.
While birding with David Thometz at Erwin Fishery Park on May 6, I spotted a male Blackpoll Warbler.
This little bird was a life bird for David. It was also the first time I have seen a Blackpoll Warbler in Unicoi County. My only other sightings of a Blackpoll Warbler took place at Winged Deer Park in Johnson City and Sycamore Shoals State Park in Elizabethton.
The Blackpoll Warbler was foraging in some low shrubs, and then moved to some taller trees. In addition, we observed a flock of about 15 Cedar Waxwings and a Gray Catbird. The Blackpoll Warbler, which nests as far north as the boreal forest of Canada, is a long-distance migrant, returning to South America each fall to spend the winter months. The spring migration is mostly an overland route. In fall, however, these warblers gather in the northeastern United States and then make an incredible journey over the Atlantic Ocean to northern South America. As a result, the Blackpoll Warbler is an extremely rare migrant in the fall in Northeast Tennessee.
In the wetland area adjacent to the Erwin Fishery Park pond, we saw two Spotted Sandpipers and two Solitary Sandpipers.
The next day, I returned for a few minutes to have a quick look around Erwin Fishery Park. As I started to leave, I saw movement in some shrubs. I focused my binoculars and saw a male Blackpoll Warbler. Was it the same individual from the previous day or a different bird making a migration stop? I do know that reports of Blackpoll Warblers have seemed more common this spring.
•••••
Gil Derouen and Reece Jamerson were with me when we observed a male Prothonotary Warbler in the pasture adjacent to Austin Springs on Boone Lake in Washington County on May 8. The Prothonotary Warbler is a unique member of its family in being the only warbler in the eastern United States to nest in cavities. They will also use nest boxes provided by human hosts.
The Prothonotary Warbler’s common name drew inspiration from officials in the Catholic Church who carried out religious and legal duties and sometimes wore golden robes. The Prothonotary Warbler is also known as “golden swamp warbler” in some regions of the country. I like both names, but “Golden Swamp Warbler” is probably more descriptive of this bird.
The bird’s scientific species name, citrea, is a reference to this warbler’s golden-lemon coloration.
In addition, we saw an American Kestrel and two Spotted Sandpipers at Austin Springs. We also watched a Tufted Titmouse carrying nesting material into a nest box.
Later that day we stopped at Paddlecreek Pond near Bristol in Sullivan County. We observed one Semipalmated Sandpiper, two Least Sandpipers, two Solitary Sandpipers and a Spotted Sandpiper. On a fence post next to the road along the pond, we saw and heard a Grasshopper Sparrow. Other birds present included Killdeer, Green Heron, Great Blue Heron, Cliff Swallow, Barn Swallow and Eastern Kingbird.
At Winged Deer Park in Johnson City, we added to our trip list with a Scarlet Tanager, Hooded Warbler, Yellow-throated Vireo, Red-eyed Vireo, Indigo Bunting, Ruby-throated Hummingbird and Baltimore Oriole.
•••••
I spent some time after getting home from work on May 10 in the yard. I was rewarded with a fascinating observation of a Kentucky Warbler in the overgrown tangles near the remains of the old springhouse. The bird was foraging, snapping up the occasional flying gnat-like insect.
Then, only a short while later, I kept an eye on a stand of willow trees near the creek. I had been watching only a brief time when I observed a male Magnolia Warbler. I’d forgotten how splendid these warblers look in springtime. This bird was busy foraging, too, and didn’t do any singing, although a nearby Gray Catbird sang enough to best both these warblers.
Other warblers are present in the woodlands around my home, but I often know of their presence only from their songs. Some of the resident warblers include Black-and-white Warbler, Hooded Warbler, Ovenbird and Chestnut-sided Warbler.
The Kentucky Warbler is one of the few warblers named for a state. The others are the Tennessee Warbler and the closely related Connecticut Warbler.
The Kentucky Warbler spends much of its time close to the ground, although in the spring the males will seek elevated perches in the forest canopy to sing their loud, ringing songs.
•••••
Lisa Botts on Bishop Circle in Elizabethton is waiting for her Ruby-throated Hummingbirds. In an e-mail, she informed me that she has both a hummingbird feeder and flowers awaiting the arrival of these tiny birds. So far, however, she has had no luck.
I advise patience and, if that doesn’t produce results, she could possibly add more flowers and perhaps even a second feeder. The initial migratory push of hummingbirds is now past, but some hummingbirds always remain in Northeast Tennessee.
May 28th, 2007
bsc-eoc.org
The Tree Swallow is one of the most familiar and most common birds in eastern North America. While it normally nests in tree cavities excavated by other species like woodpeckers, it also readily accepts nest boxes. Along with its abundance, this feature makes the Tree Swallow a favourite species for biologists to study on its breeding grounds.
Through Bird Studies Canada, Long Point Bird Observatory monitors three nest box “colonies” of Tree Swallows at Long Point, two on the “mainland” near Port Rowan (at the Port Rowan sewage lagoons and adjacent to agricultural land at Mud Creek) and the third at the Tip of the Point. Each colony contains 50-65 nest boxes.
In May through June, volunteer research assistants check nest box contents daily, weigh eggs and young, and band the adults and the young. The amount of food available to the swallows at each site is measured every day with specially-designed suspended nets that sample the abundance of flying insects. Twice-daily weather records are also collected at each site.
The objectives of this project are (1) to provide a long-term record of breeding performance of Tree Swallows in relation to their food supply and climate, (2) to provide other opportunities for research on breeding swallows, and (3) to provide training in field ornithology for students and other volunteers.
The Long Point Tree Swallow project has a superb set of data relating food abundance and weather conditions to breeding performance at 3 sites, extending over a 22-year period. This provides a sound basis for research on a variety of topics. Here are some results from Tree Swallow research at Long Point:
• Egg laying occurs later in cold springs and is usually 3-5 days later at the Tip of Long Point than on the mainland, because the proximity of Lake Erie results in cooler spring temperatures at the Tip.
• The number of eggs laid (clutch size, usually 4-7 eggs) by female Tree Swallows depends on the abundance of insects available to them prior to laying.
• Many adult swallows return year after year to the same site, sometimes to the same nest-box, and some of their young also return.
• Few Tree Swallows live more than six years, but one female banded at the tip of the point lived for 11 years. She bred at Long Point in at least 10 years from 1970 to 1980. She held the world record for Tree Swallow longevity until 1998 when a 12 year-old male was found at the Sewage Lagoon.
• Young Tree Swallows grow faster at the Lagoon, where insects are more abundant than at other sites where food is scarce.
The first Tree Swallow studies at Long Point began at the Tip of Long Point in the late 1960s. Geoff Holroyd conducted his Ph.D. research (University of Toronto) on resource allocation in swallows, Purple Martins and Eastern Kingbirds in 1970-74. At the same time David Hussell did postdoctoral research on relationships between insect abundance and parental care in Tree Swallows. Diane DeSteven (University of Michigan) studied effects of brood size and female age on reproductive success in 1975-76. The current program of monitoring performance in relation to food abundance at three sites began in 1977. In 1980-84, Terry Quinney conducted Ph.D. research (University of Western Ontario) and postdoctoral research, which mainly involved comparing breeding performance at two mainland sites with different food abundances. In 1982-84, David Hussell did research on parent-offspring food-provisioning interactions.
Recent Activities and Results, 1997-1999
After 3 decades of research, we can still say that each year has something new and different to offer. Despite the looming prospect of climate warming, 1997 proved to be the latest year on record, with no eggs laid until 18 May. By contrast, 1998 and 1999 were the earliest ever with the first eggs laid on 8 May in both years.
A pattern that seems to be emerging is that the delay between clutch initiations at the mainland sites and the tip of the point is greater in early seasons than in late ones. Median date of first eggs laid (by females at least 2 years old) was only 2 days later at the tip than on the mainland in 1997, but was 5 and 7 days later in 1998 and 1999, respectively. Presumably the cooling effect of the lake at the Tip of the point moderates the impact of early warm spells that stimulate early laying.
In 1998, a cold spell in early June reduced insect abundance and adversely affected many broods that were 2-8 days old at that time. A few nestlings died, but the biggest effect was retardation of flight feather growth in the survivors. Body weigh subsequently returned to normal, but there was no “catch-up” in feather growth. Consequently fledging was unusually late and some broods remained in the nest boxes until 22 days of age (versus about 18 days normally). Still, the young appeared to be in good condition at fledging time, so the ability to retard growth and remain longer in the nest appears to be an adaptation to a variable food supply.
In 1999, females laid more eggs at the Tip (mean 5.93, N=58) than at the Sewage Lagoon (mean 5.82, N=38) or Mud Creek (mean = 5.25, N=49). For the third year in succession, clutch sizes at the Lagoon averaged lower than at the Tip. This is very unusual, and is indicative of a crash in insect abundance at the Lagoon, which is reflected in our daily insect catches. Formerly, the Lagoon was consistently the most productive site with clutch sizes averaging as high as 6.4 in some years.
There were no major weather events in 1999, and productivity was generally high. Drs. Stephen Yezerinac and Robert Montgomerie, Queens University, investigated the relationships between plumage colour, mate choice and reproductive performance at the 2 mainland sites. Since birds can see ultraviolet light, they see the world and each other differently from humans. Plumage colour was measured on adults with a field spectrometer. Blood samples were taken from adults and young for DNA analysis. Previous work elsewhere has shown that some brood members result from extra-pair copulations (i.e. the eggs were fertilized by another male). The DNA analyses will show whether the same pattern exists at the LPBO sites and will indicate whether plumage colour is related to ability to obtain and/or prevent extra-pair copulations.
Also in 1999, David Hussell ran a series of experiments to try to determine whether the visual component of the brood’s begging signals contributes to stimulating adults to bring food to their young. It has long been known that the begging calls of the young stimulate parental feeding, but the role of the visual signal remains unclear. These experiments involved videotaping 9 and 12 day-old broods in a specially designed nest box.
Tree Swallow Banding
One component of the Tree Swallow program is to band all adults and young each year (about 1000 swallows annually). All of these banding and recapture data have recently been computerized, with a view to conducting analyses of survival and inter- and intra-area movements.
The banding has led to some interesting discoveries. For example, on 3 July 1998, volunteer Susan Anderson trapped a male swallow at Lagoon nest box # 30 that had been banded as a nestling at box #44A (about 49 metres from the recapture site) on 14 June 1986. It had hatched on 1 June 1986, so it was 12 years and 32 days old when recaptured in 1998. This is a new world record for longevity in the Tree Swallow!
In 1999, Charles Francis and David Hussell analyzed site fidelity of Tree Swallows, using 14,400 bandings of nestlings and 6,300 bandings and recaptures of adults accumulated from 1977 to 1998. They presented a poster paper describing their results at meetings of the Society of Canadian Ornithologists (Montreal) and the American Ornithologists’ Union (Ithaca, New York), and at the 100 Years of Bird Ringing Conference (Heligoland, Germany). They showed that about 61% of males that bred at a site and returned in the following year occupied the same nest box in both years, but only 29% of females did so. Also, males that occupied a different nest box moved a shorter distance than females that moved. Overall, males tended to be more site-faithful than females.
How to Get Involved
The Tree Swallow project is coordinated for LPBO by Dr. David J.T. Hussell. He welcomes inquiries from people who may wish to volunteer one or more weeks of their time in May or June to assist with the swallow project. Tree Swallow assistants also usually have opportunities to be involved in LPBO’s migration monitoring program in May. Room and board are provided for long-term volunteers (1 month or more). Help with data compilation and nest-box maintenance and construction may also be needed at other times of the year. This project is an excellent scientific introduction to ornithological fieldwork for students planning to conduct thesis-level research, or who are looking for research projects to work on. Inquiries from potential research collaborators are also welcome. For more information, contact:
Dr. David Hussell
34 Carr Place
Kanata, Ontario, Canada K2K 1K7
Tel: 613-592-0616
Applications for May/June fieldwork should be received no later than 31 March and include a brief résumé and a covering letter, indicating dates available and whether you hold a driver’s license.
For more information on results from the Tree Swallow program at Long Point:
Bradstreet, M.S.W. 1969. Consecutive nesting of female Tree Swallows at Long Point, Ontario. Ontario Bird Banding 5: 68-71.
Holroyd, G.L. 1972. Resource use by four avian species of aerial insect feeders. M.Sc. thesis, Univ. of Toronto.
Holroyd, G.L. 1975. Nest site availability as a factor limiting population size of swallows. Can. Field Nat. 89: 60-64.
Holroyd, G.L. 1983. Resource use by four avian species of aerial insect feeders. Ph.D. thesis, Univ. of Toronto.
De Steven, D. 1978. The influence of age on the breeding biology of the Tree Swallow, Iridoprocne bicolor. Ibis 120: 516-523.
Dunn, E.H. 1979. Age of effective homeothermy in nestling Tree Swallows, Iridoprocne bicolor, according to brood size. Wilson Bull. 91: 455-457.
DeSteven, D. 1980. Clutch size, breeding success, and parental survival in the Tree Swallow. Evolution 34: 278-291
Hussell, D.J.T. 1982. Longevity and fecundity records in the Tree Swallow. N.Am. Bird Bander 7: 154.
Hussell, D.J.T. 1983a. Tree Swallows raise two broods in a season. Wilson Bull. 95: 470-471.
Hussell, D.J.T. 1983b. Age and plumage color in female Tree Swallows. J. Field Ornithol. 54: 312-318.
Quinney, T.E. 1983. The relation between food abundance and reproductive performance of Tree Swallows. Ph.D. thesis, University of Western Ontario.
Quinney, T.E. 1983. Tree Swallows cross a polygyny threshold. Auk 100:750-754.
Quinney, T.E. and C.D. Ankney. 1985. Prey size selection by Tree Swallows. Auk 102: 245-250.
Quinney, T.E. 1986. Male and female parental care in Tree Swallows. Wilson Bull. 98:147-150.
Quinney, T.E., D.J.T.Hussell and C.D. Ankney. 1986. Sources of variation in growth of Tree Swallows. Auk 103: 389-400.
Hussell, D.J.T., and T.E. Quinney. 1987. Food abundance and clutch size of Tree Swallows, Tachycineta bicolor. Ibis 129: 243-258.
Hussell, D.J.T. 1988. Supply and demand in Tree Swallow broods: a model of parent-offspring food-provisioning interactions in birds. Am. Nat. 131: 175-202.
Hussell, D.J.T. 1991. Regulation of food provisioning in broods of altricial birds. Acta XX Congressus Internationalis Ornithologici: 946-960.
Bishop, C.A., M.D. Koster, A. Chek, D.J.T. Hussell, and K. Jock 1995. Chlorinated hydrocarbons and mercury in sediments, Red-winged Blackbirds (Agelaius phoeniceus) and Tree Swallows (Tachycineta bicolor) from wetlands in the Great Lakes - St. Lawrence River Basin. Environmental Toxicology and Chemistry 14: 491-501.
Hussell, D.J.T., and S.J. Anderson. 1999. Longevity record for the
Tree Swallow. North American Bird Bander 24: 6-8.
May 23rd, 2007
pubmedcentral.nih.gov
Proc Natl Acad Sci U S A. 2001 January 2; 98(1): 16–17.
Copyright © 2001, The National Academy of Sciences
Lee Alan Dugatkin*
Department of Biology, University of Louisville, Louisville, KY 40208
*E-mail: lee.dugatkin@louisville.edu.
It may metaphorically be said that natural selection is daily and hourly scrutinizing, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life. We see nothing of these slow changes in progress, until the hand of time has marked the lapse of ages.
—Charles Darwin (1)
The study of adaptive behaviors lies at the very heart of behavioral ecology. Although there is certainly no lack of debate about what constitutes an adaptation (2), most researchers in the field probably would not quibble with the statement that adapted traits are those that are the product of natural selection. Evidence for adaptive behavior then can be found only when the criteria for the process of natural selection to operate are met, namely: (i) variation in the trait of interest, (ii) fitness differentials across variants of the trait in question, and (iii) a means by which the trait is transmitted across generations.
Meeting all three criteria is hardly simple, even for easily quantifiable traits (e.g., certain morphological traits) and gets even more dicey when we start talking about behavioral traits (3). The task becomes more and more daunting when the behavior becomes more and more socially mediated. So, when Brown and Brown (4) in a recent issue of PNAS claim to have found evidence that preference for group size differs among cliff swallows (Petrochelidon pyrrhonota), and that this preference is heritable, it’s big news.
Since its inception, behavioral ecology and sociobiology have had something of a love/hate relationship with animal group size.
Since its inception, behavioral ecology and sociobiology have had something of a love/hate relationship with animal group size. Group size seems so fundamental to an animal’s well-being—in terms of foraging, predation, disease transmission, mating opportunities, etc.—that it seems reasonable to posit that natural selection should operate in ways to modulate group size according to ecological, genetic, and social circumstances (5). Many studies have, for example, manipulated group size in a given population to examine group size effects on antipredator behavior and foraging (6). In addition, between-population comparisons of group size in a given species often suggest that group size varies as one might expect from a cost/benefit analysis (e.g., ref. 7). Putting together all of the pieces necessary to demonstrate that animals modulate their group size via some heritable preference function, however, has turned out to be incredibly difficult. Yet Brown and Brown demonstrate that with the right system, a detailed knowledge of the biology of the animal in question, and almost endless patience, it can be done.
Brown and Brown have been studying cliff swallows for more than 20 years (8), and their long-term study has proven to be a treasure chest that behavioral ecologists will be drawing from long into the future. What makes their work so powerful is that the vast majority of it takes place in the field, under natural circumstances. And so it should come as no surprise that this is precisely how they opted to study the heritability of group size preferences. That being said, one can’t underestimate how difficult studies of heritability in nature genuinely are. It was only with a very meticulous protocol involving many subjects, careful experimental manipulation, and a deep understanding of cliff swallow behavior (the sort of understanding that only emerges after decades of interaction with subjects) that Brown and Brown could have pulled off studying the heritability of complex traits in the wild.
In experiment 1, using five clusters of cliff swallow colonies, Brown and Brown tackled group size preference and its heritability in two ways. With an impressive sample size of 2,581 birds, the group size of individual swallows was found to be statistically similar to the group size in which their parents lived. This was true for birds that bred at the same site of their parents and birds that emigrated, suggesting that the correlation between parent and offspring was not a function of a common environment.
Using nestlings from two large and five small colonies, Brown and Brown also undertook a classic cross-fostering experiment with cliff swallow young. About half the young from the hundreds of nests in the large colonies were removed, and young from small colonies were placed in their stead. Similarly, half the young in small colonies were replaced by young from large colonies. In all manipulated nests then, Brown and Brown had offspring from large and small colonies. Of the 1,968 birds in their cross-fostering experiment, 721 were recaptured, and the results were as clear as one could hope for.
Cross-fostered birds chose breeding colonies that were similar in size to their place of birth. More to the point, Brown and Brown were able to make some fascinating heritability comparisons from their cross-fostering data. The heritability of group size preference for swallows that remained in their natal nests was positive and similar to that of experiment 1. When examining the preference for group size, a parent-offspring heritability analysis showed a significant positive relationship between group size preference in offspring, when the biological parent of such offspring were considered. When the “foster” parent and cross-fostered offspring’s group size preference were regressed against each other, a negative heritability was uncovered (birds avoided breeding in group sizes that were similar to those in which they were raised). Further, in all of the analyses run by Brown and Brown, father-offspring heritability estimates were higher than mother-offspring heritabilities, suggesting that maternal effects did not play a large role in group size preference.
One of the many lessons that behavioral ecologists and sociobiologists have learned since E. O. Wilson’s classic Sociobiology (9) is that social behavior in nonhumans is clearly much more complex than was originally thought. Both empiricists and theoreticians now recognize that social behavior in animals often involves complex “if-then” rules, choice of partners and even choice of social environments. Although some of this complexity may well be due to cultural transmission of behavior (10, 11), much of it likely will be the result of natural selection acting on such complexity.
What Brown and Brown show us so eloquently is that even when the trait in question is complex, it might still have a heritable basis. Wherever he may be, Darwin is probably smiling right about now. We may not be able to observe the “slow changes in progress” that often may be associated with behavioral evolution, but we certainly can study them with the empirical, theoretical, and conceptual tools now available to behavioral ecologists (12).
References
1.
Darwin, C. On the Origin of Species. London: Murray; 1859.
2.
Reeve H K, Sherman P W. Q Rev Biol. 1993;68:1–32.
3.
Mousseau T A, Roff D A. Heredity. 1987;59:181–197. [PubMed]
4.
Brown C, Brown M B. Proc Natl Acad Sci USA. 2000;97:14825–14830. [PubMed]
5.
Pulliam, R.; Caraco, T. Behavioral Ecology. Krebs J, Davies N. , editors. Sunderland, MA: Sinauer; 1984. pp. 122–148.
6.
Giraldeau, L A.; Caraco, T. Social Foraging Theory. Princeton: Princeton Univ. Press; 2000.
7.
Liley, N.; Seghers, B. Functions and Evolution in Behavior. Baerands G, Manning A. , editors. Oxford: Oxford Univ. Press; 1975. pp. 92–118.
8.
Brown, C.; Brown, M B. Coloniality in the Cliff Swallow: The Effect of Group Size on Social Behavior. Chicago: Univ. of Chicago Press; 1996.
9.
Wilson, E O. Sociobiology: The New Syn-thesis. Cambridge, MA: Harvard Univ. Press; 1975.
10.
Heyes, C M.; Galef, B G. Social Learning in Animals. London: Academic; 1996.
11.
Dugatkin, L A. The Imitation Factor: Evolution Beyond the Gene. New York: The Free Press; 2001.
12.
Dugatkin L A. , editor. Model Systems in Behavioral Ecology: Integrating Conceptual, Theoretical, and Empirical Perspectives. Princeton: Princeton Univ. Press; 2001.
May 22nd, 2007
ncbi.nlm.nih.gov
[Article in French]
Houdret N,
Lhermitte M,
Degand P,
Roussel P.
A glycoprotein was purified from the aqueous extract of “edible bird’s nest” (Collocalia) using free flow preparative electrophoresis and represented the main fraction of Collocalia glycoproteins.
This glycoprotein is homogeneous upon agarose electrophoresis and slightly polydisperse upon ultracentrifugation (S So 20w = 3,0). The carbohydrate moiety contains galactose, mannose, glucosamine, galactosamine and sialic acid, which is completely released by Clostridium perfringens or Diplococcus pneumoniae neuraminidases and has the same chromatographic behaviour as N-acetyl-neuraminic acid. The peptide part of the glycoprotein is rich in serine, threonine and proline. About 40 p. cent of the hydroxyaminoacids are involved in carbohydrate-peptide linkages.
PMID: 1182216 [PubMed - indexed for MEDLINE
May 21st, 2007
natlands.org
Tree swallows are one of the primary competitors of bluebirds for nest space. When the bluebirds abandoned the nest they they had begun building in our nest box in 2006, a pair of tree swallows took it over and successfully raised a brood of young.
Tree swallows are beautiful birds, with metallic teal coloring on their head, wings and back, and white coloring underneath. They are spectacular aerial acrobats, catching insects on the wing for most of their diet.
Tree swallows are migratory, spending winters in the southern U.S., Mexico and Central America and returning north in early spring.
Tree swallows typically begin building their nests in April, using small twigs, grass or pine needles, then lining the nest with feathers.
May 18th, 2007
several hundred yards to the woodland on a circuitous route, making a noticeably slow and labored return against the strong wind. It seemed that the flycatchers sought all their food in the distant woodland. They never were seen perched any- where in the dead forest, except close by or on the nest-tree, immediately before entering the nest or immediately after leaving it.
Since there are many decaying or partly decayed live-oaks in the woodland offering apparently suitable nesting sites, and since the skeletons of the sand-killed trees come right up to the sand wall at the edge of the woodland, it is puzzling that these birds should go so far out into the wasteland, so far from their foraging area, to establish their nests. In flying between the edge of the woodland and the nest sites, the birds passed dozens of dead trees, every one of which contained cavities that appeared (to the human eye) to be identical with those chosen by the birds. I am certain that none of these was being used by other birds, so that competition could not have been a factor in selecting the sites. This open wasteland, dotted with dead trees, is entirely free of snakes and other predators, so that the nests, because of their location, were completely insured against predatory enemies; but is it reasonable to suppose that the flycatchers could realize that fact, and act accordingly? The nests would also have been immune from attack in dead trees near the sand wall adjacent to the foraging area; in other years, I have found crested flycatchers nest- ing here, within 20 yards of the woodland.–WxLLx.•M L. ENGELS, Department of Zoology, University of North Carolina, Chapel Hill, N. C.
Probable destruction of queen bees by swallows.–Mr. Fred M. Sickler of Bonsall, California, noted my article (Condor, 47: 261-264, 1945) on swallows selecting drone bees. He is of the opinion that birds cause a very negligible loss of worker bees, that the loss of drones is a good riddance, and that swallows do real harm in eating queen bees. Mr. Sickler writes: “This summer I noticed large numbers of barn, cliff and green- back swallows flying about 100 feet above one of my apiaries for several weeks. Fifteen parent hives became queenless after swarming, a real loss in more ways than one. Worker bees fly close to the ground whereas queens and drones fly high and slow. There was no loss of queens at another apiary three miles away where no swallows had appeared.” To the list of bee-eating birds which appeared in the above quoted article, Mr. Sicklet adds the California shrike, Lanius ludovicianus gambeli, and Brewer’s black- bird, t•uphagus cyanocepbalus. I saw a California brown towhee, Pipilo fuscus, apparently pick up and eat a bee from the alighting board of my hive, but as I have seen this only once I cannot be sure of the eaSe.–CH.•PM.•N G•, 2970 Sixth Ave., San Diego, California. Fall aggregations of cliff swallows in the Allegheny Mountalns.–For the past 20 years I have been observing aggregations of northern cliff swallows, Petro- 1⁄2helidon pyrrhonota, in fall migration through West Virginia and Maryland sections of the Alleghenies. These aggregations are usually to be found during the last week of August and the first 10 days of September. They almost invariably occur in elevated valleys between the high Allegheny ridges. I have not found large flocks of migrating cliff swallows in autumn in any lowland section of the region. One of the remarkable features of these aggregations is that the birds return to the same sections of telephone and power line wire each season. Mr. Brown Beard of Barrow, West Virginia, a careful observer, tells me that in 30 years the swallows have not failed to appear along a certain section of State Highway No. 28, near his
home. During seven recent seasons I have found them in this locality in numbers between 2000 and 3000 annually. Other places where the swallows occur regularly in late August and early Septem- ber are: near Oakland, Garrett County, Maryland; near Daily, Randolph County, West Virginia; at Red Creek, Randolph County, West Virginia; and near Greenbank and Marlinton, Pocahontas County, West Virginia. Despite the fact that there are hundreds of miles of telephone and power lines through this region, the cliff swallows are to be found in almost exactly the same locations year after year. Sections of wire selected for these migration roosts are usually along public high- ways. There are always broad mountain meadows near by, and usually there is a stream in the vicinity. Flocks number between 2000 and 5000 birds, many actual counts having been made. In eight such aggregations examined carefully in the autumns of 1947 and 1948, I was unable to find a single individual of any other species of swallow. Gross, in one of the Bent bulletins (U.S. Nat. Mus. Bull. 179: 466, 1942) states, “The Cliff Swallow migrates in flocks, and practically all the reports of the large numbers seen throughout the migration route mention the association of the Cliff Swallow with Barn and Tree Swallows as well as other members of the family.” Mixed flocks are certainly the rule during spring migration in West Virginia and western Maryland, but they seldom occur in autumn. On the evening of September 3, 1947, I saw a striking variation in roosting be- havior of cliff swallows. The large aggregation which appears annually near Bar- tow, West 3⁄4irginia, usually roosts on wires on either side of the highway. On this evening, however, all members of the flock forsook the wires and settled to roost in a near by cornfield. The birds used both tassels and the axes of corn leaves as roosting perches. That cliff swallows which occur in autumn in the Allegheny region may assemble from a vast breeding area is evidenced by a single banding record. Gross (op. tit.) tells of a bird of tkis species banded on June 14, 1937, at Dell Rapids, South Dakota, and recovered on July 16, 1937, at Ghent, West Virginia, a distance of some 1200 miles.–Ma•RIC• BROOKS, West Virginia University, Morgantown, W. Va. January singing in the black-capped chickadee and other species,- Francis H. Allen’s observations on the January singing in the black-capped chicka- dee, ,Parus atricapillus, in The Auk (64: 616, 1947) coincide with my own, and it is npon his suggestion that these notes have been written. I wish to point out, however, that my records only date back to the winter of 1944-45. My observations are based mainly on a special study during January, 1948, after my interest was aroused by Saunders’ article ‘Beginning of song in the spring’ (Auk, 64: 97, 1947)and Allen’s comments thereupon in the October, 1947, issue of The Auk. At our home, which is located in the woods halfway between North Bay and Mattawa in central Ontario, some black-capped chickadees are resident all year, as shown by banding. During January, 1945 and 1946, my records note January singing, and in 1947, the first “phoebe”-song was noted on January 7. About 20 black-capped chickadees were regular visitors at my feeding station during January, 1948. No observations were made on January 10 and 24. During the remaining 29 days the blackcaps were heard singing every day except January 2, 3, 15, 18 and 19. The time preferred for singing was apparently just before sunup when one or several birds would begin to sing; sometimes they continued singing for 10 to 15 minutes.
May 16th, 2007
Suffolk Evening Star, UK - May 11, 2007
ONE bird has become so closely associated with summer that a popular catchphrases inextricably links the two - one swallow doesn’t make a summer
The swallow is the archetypal summer visitor, yet there’s much more to swallows than simply being a popular migrant.
Swallows have a place in our hearts for many reasons. They are mentioned in many stories and poems and centuries of folklore surround them. Many of them nest close to people. They are also good indicators of our changing environment, both in the UK and Africa.
Yet many people find it hard to distinguish between swallows, swifts and house martins.
Let’s start with some of the folklore. The popular phrase “one swallow doesn’t make a summer” is certainly true. The first swallows to reach the UK usually arrive in mid March, but it is mid April before they are widespread. This year, they brought dry sunny weather with them, but it’s not always the case. Swallows then remain with us until late September, with a few stragglers until late November.
In Mediaeval times it was thought that swallows spent the winter at the bottom of a pond. As European explorers travelled farther afield, and science revealed more of nature’s secrets, their true winter destinations were discovered.
European swallows migrate to sub-Saharan Africa, with most British birds heading as far as South Africa. The journey is arduous as they must cross the vast Sahara desert, running the gauntlet of sandstorms and lack of insects. Each year the desert expands southwards into the Sahel, making the journey ever harder.
The English Channel and Mediterranean Sea are also hazardous crossings, and many young swallows will fail to make the journey successfully. Some succumb to starvation, others to storms, and some will fall victim to hunters in southern Europe or West Africa.
Fortunately, many swallows do succeed in reaching South Africa, and return the following spring. Amazingly, most return not just to the same area, but to the same barn in which they were born. How they navigate so precisely is still not understood, but there’s no need for that annoying voice we hear from our in-car sat navs.
Swallows naturally nest on any exposed ledge or overhang, so buildings provide an ideal alternative. Many nest in barns, earning them their modern name of barn swallow. At RSPB Minsmere nature reserve, several pairs nest around the sluice and frequently pose for photos on the nearby fence.
The nest is a mud cup, bound together with saliva. Following the dry spring this year, some swallows may struggle to bind the mud, so if you have them nesting nearby why not create a nice muddy puddle for them.
Each pair will usually rear two broods of youngsters every summer, and some will even manage three. The adults spend the long summer days skimming low over the ground in search of insects. If feeding is good, many young swallows will survive to start the journey south.
Rather than the swallow, it’s actually the swift that signals summer’s arrival for me, especially the almost eerie screaming as small parties of them swoop through our housing estates in the evenings.
You can buy special nest boxes for swifts, swallows and house martins, helping to compensate for the increasing loss of suitable nest sites as old buildings are demolished or roves modernised. Sand martins, too, take to artificial homes, and many wetland nature reserves have colonies nesting in a concrete sand martin ‘cliff’.
So how do you identify a swallow?
Colour:
Swallows may at first glance appear to be black and white birds, but they are actually extremely colourful. The upperparts are dark metallic blue, and at times almost glint in the sun. They have a dark red throat and white belly.
House martins are even darker blue and slightly less metallic, with even brighter white underparts. They are slightly smaller than swallows, but the their best distinguishing feature is a bright white rump separating the back from the tail.
Sand martins are sandy brown above and white below with a brown breast band.
Swifts are larger, dark brown birds with long wings giving them a distinctive scythe-shape in flight. They are extremely agile as they catch tiny insects high in the sky.
Tail:
Probably the best identification feature for swallows is their very long tail streamers.
House martins’ tails have only a shallow V at the tip.
Nest:
House martins build a mud nest, but it is almost a completely enclosed cup with a small hole at the top. The nest is built under the eaves of houses. You may be lucky enough to have these beautiful little birds nesting on your house.
Sand martins nest in sandy cliffs, digging a tunnel up to one metre long with a nest chamber at the end.
You’re unlikely to see sand martins in the middle of Ipswich, but head to a flooded former gravel pit and you can watch the smallest martins found in the UK. At Minsmere, they nest in man-made cliff outside the tearoom overlooking what used to be the reserve car park.
Swifts nest in crevices in tall buildings, such as churches, and you may even have them nesting in your roof.
Timing:
Sand martins are usually the first migrants to return in the spring, arriving as early as the first week of March. They leave early though, usually by September. Most only travel as far as West Africa.
Swifts are among the last migrants to return, usually in early May, and will be the first to leave. By mid August they will all have gone.
(at Minsmere unless stated)
May
13 at 10am to 2pm: Migrants on the move at Heybridge Basin - free event, simply turn up
14, 17, 23, 25 and 29, and June 5 at 9.30am: Discovering Minsmere
15 and 24, June 1 and 6 at 7am: Bitterns and harriers
20 and 26, Saturday 2 and 3 at 9.30am: Weekend wildlife walk
21 at 7am: What’s About at Minsmere
27 at 9.30am: Heathland wildlife
29 at 1pm: Fascinating flora
30 and June 7 at 9.30am: Birdwatching for beginners
31 and June 7 at 4.30pm: Summer evening at Minsmere
June
2 and 3, 10am - 4pm: Optics day
2 at 11am: RSPB walk at Snape Maltings Farmers Market
2 at 9.30pm: Moth night at Wolves Wood, Hadleigh (01473 328006 to book)
3 at 9pm: Nightjars
Contact: For general enquiries The RSPB 01767 680551 or e-mail enquiries@rspb.org.uk , RSPB Minsmere nature reserve, Westleton, 01728 648281 or e-mail minsmere@rspb.org.uk
www.rspb.org.uk
May 14th, 2007
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