61. Site Tenacity Many birds return to the same nesting site each season. This essay discusses why this should be so. http://www.stanford.edu/group/stanfordbirds/text/essays/Site_Tenacity.html

Site Tenacity T he tendency to return each season to the same nest site or breeding colony is known as "site tenacity," "site fidelity," or "philopatry." The realization that site tenacity exists grew out of ornithologist Oliver Austin's long-term studies of Common Terns in Massachusetts. Austin found that individual terns tended to return to the same colony site and often to the same nest site within the colony. From banding studies, he discovered that this tendency increases with the age of the bird. Subsequent field studies have shown that this behavior occurs to varying degrees in a wide variety of North American birds including Common Goldeneye, Least Tern, Black Skimmer, Spotted Sandpiper, Long-billed Curlew, Broad-tailed Hummingbird, Bank Swallow, and Barn Swallow. Avian biologists think the major advantage of returning to an established breeding site is that the bird's familiarity with the area results in reduced susceptibility to predation and other adverse conditions. Studies have shown that sex and age of the nesting bird, prior reproductive success at the particular site, and physical stability of the nest site are all important factors affecting site tenacity. For all of the aforementioned species, birds that successfully rear young are more likely to return to the nest site the following year than birds that are unsuccessful. A finer discrimination is made by Black Skimmers, which are more likely to abandon a colony site following predation than following flooding. Presumably future failures as a result of predation are more predictable than those resulting from flooding.

62. Edward Sabine - Wikipedia, The Free Encyclopedia General Sir Edward Sabine KCB FRS (14 October 1788 – 26 June 1883) was an Irish astronomer, geophysicist, ornithologist and explorer. Two branches of Sabine's work in particular http://en.wikipedia.org/wiki/Edward_Sabine

Edward Sabine From Wikipedia, the free encyclopedia Jump to: navigation search Sir Edward Sabine Born 14 October 1788 Dublin Died 26 June 1883 East Sheen Nationality Irish Fields Astronomy ornithology General Sir Edward Sabine KCB FRS (14 October 1788 – 26 June 1883) was an Irish astronomer geophysicist ornithologist and explorer Two branches of Sabine's work in particular deserve very high credit: Determination of the length of the seconds pendulum , a simple pendulum whose time period on the surface of the Earth is two seconds, that is, one second in each direction; and extensive researches connected with the Earth's magnetic field . He led the effort to establish a system of magnetic observatories in various parts of British territory all over the globe and a great part of his life was devoted to their direction, and to the reduction and discussion of their observations. While the majority of his research bears on one or other of the subjects just mentioned, other research deals with such widely different topics as the birds of Greenland Sabine's Gull is named for him)

63. The Earthlife Web - Flight In Birds How do birds fly? An introduction to flight in birds examining wing shape, airflows, flapping flight and gliding. http://www.earthlife.net/birds/flight.html

Bird Flight The fact that birds fly is one of the most amazing things about them. The sight of crows or ravens playing in the wind, of seagulls gliding effortlessly along seashore or of buzzards soaring silently about the countryside always inspires me. There is no doubt that if I had the ability to change into another animal, something other than a human being I would be a bird simply because of the incredible wonder of flight on a sunny day. Birds are the ultimate flying machines, though insects have been doing it for longer and in many cases are more versatile; their small size makes the physics of it much easier. Birds fly far better than any machinery mankind has yet made and like our machines they use their wings and tails in a variety of ways to achieve their expertise. Bird flight is dependent on the shape of the birds wings and the way they use them. Generally, bird flight can be divided into two modes of functioning, i.e. gliding or soaring flight, and flapping or powered flight. Wing Shape The dynamics of bird flight like all physical actions are governed by the laws of physics. In its simplest expression, flying is a balance between two sets of forces. lift and weight, and thrust and drag. Weight is the result of gravity and is reduced as much as possible in birds (see anatomy). Lift is generated by the flow of air over the wings.

64. Edward Sabine Sir Edward Sabine Born 14 October 1788(178810-14) Dublin Died 26 June 1883 (aged 94) East Sheen Nationality Irish Fields astronomy ornithology General Sir Edward Sabine http://pandapedia.com/wiki/Edward_Sabine

65. BIRDNET: Feather Quest Interactive quiz. Can you identify the birds from which these feathers come? http://www.nmnh.si.edu/BIRDNET/FeatherQuest/FeatherQuest.html

Feather Quest Feathers are the defining characteristic of the Class Aves - the birds. Much can be learned about a bird from and examination of its feathers. The object of this Feather Quest is to identify the bird from a photograph of a feather. Follow the link below to begin your Quest. Begin Feather Quest Return to JUST FOR FUN Return to BIRDNET

66. Dungeness Bird Observatory Site Map Home Page http://www.dungenessbirdobs.org.uk/siteframe.html

67. Territoriality Article describing how birds try to exclude others of the same species from their home range. http://www.stanford.edu/group/stanfordbirds/text/essays/Territoriality.html

Territoriality M any birds attempt to exclude other birds from all or part of their home range the area they occupy in the course of their normal daily activities. When they do, we say they are defending a "territory." Most often this behavior occurs during the breeding season and is directed toward members of the same species. Territoriality appears, in most cases, to be an attempt to monopolize resources, especially food resources or access to mates. But territoriality may also serve, in part, as a predator defense mechanism. Some birds defend their entire home range. Others defend only their food supply, a place to mate, or the site of their nest. Some tropical hummingbirds chase most other hummingbirds and other nectar-feeding birds (and some butterflies) away from favorite patches of nectar-bearing flowers. On their leks (patches of ground traditionally used for communal mating displays) grouse, some sandpipers, and some other birds defend small territories. Most colonial-nesting seabirds simply defend the immediate vicinity of their nests presumably to protect their eggs and, at least in the case of some penguins, the pebbles from which the nest is constructed. Territoriality tends to space some species of camouflaged birds and their nests rather evenly throughout their habitat; it prevents them from occurring in flocks or clusters while breeding. This, in turn, may reduce the danger from predation, since many predators will concentrate on one kind of prey after one or a few individuals of that prey type are discovered (that is, the predator forms a "search image"). Clustering can promote the formation of a search image by predators and thus reduce the security of each individual prey (birds that are not cryptic, however, may gain protection in clustering).

68. Science Museums In Georgia LEARNING TAGS Georgia, aquariums, ornithology, general science, petroleum, space exploration, gemology, herpetology, medical, planetariums, evolution, geology, technology, http://www.museumstuff.com/museums/georgia-science.php

museums showcase shop links ... Science Science Museums in Georgia LINKS TO GEORGIA SCIENCE MUSEUMS : This is a gateway page for Georgia museums, libraries and archives that have a primary theme or significant collections related to science. - We have 11 Georgia museums and archives with science collections listed in our database. - We also offer pages with a full listing of Georgia museums as well as Georgia art museums and Georgia history museums Coca-Cola Space Science Center - Columbus, GA Elachee Nature Science Center - Gainesville, GA Fernbank Museum of Natural History - Atlanta, GA Fernbank Science Center - Atlanta, GA Museum of Arts and Sciences in Macon - Macon, GA National Science Center (Fort Discovery) - Augusta, GA Robert C. Williams American Museum of Papermakin - Atlanta, GA Scitrek Science and Technology Museum - Atlanta, GA Tellus Northwest Georgia Science Museum - Cartersville, GA Tybee Island Marine Science Center - Tybee Island, GA William Weinman Mineral Museum - White, GA LEARNING TAGS : Georgia

69. Vocal Dialects Article describing how the songs of many avian species show geographic variation. http://www.stanford.edu/group/stanfordbirds/text/essays/Vocal_Dialects.html

Vocal Dialects J ust as our speech patterns vary regionally, the songs of many avian species also show geographic variation. For example, in states and provinces east of the Mississippi, the songs of Rufous-sided Towhees consist of two introductory notes followed by a buzzy trill. Songs in the Rocky Mountain states begin with a single introductory note followed by the trill, and West Coast populations have dropped the introductory notes entirely their songs are composed of just the buzzy trill. Although such geographic variation is quite evident to the human ear, we still recognize the singer as a Rufous-sided Towhee. The songs of populations often differ markedly on a much smaller geographic scale. Local variants are called dialects. They are commonly found in songbirds with populations restricted to particular habitats and separated from other populations by unsuitable terrain. The separation can be on the order of a mile or so, but in some species it can be much less. Among the White-crowned Sparrow populations of coastal California, distinct dialects may be separated by as little as a few yards in what appears to be essentially continuous habitat! Vocal dialects appear to be learned. Young birds hear the songs sung around their natal territories by their fathers and neighboring males, and acquire the peculiarities of these renditions. Factors that determine the geographic pattern of dialects include the accuracy with which the pitch and temporal characteristics of individual song components are learned, the distance young males disperse from where they hatch to where they breed, and the timing of dispersal relative to the sensitive period for learning.

70. East Of England Binoculars - Zeiss Conquest Mono 6x18 fit unnoticed into the pocket, as with the Pocket Binoculars, lower magnifications are ideal for the theatre whilst the 8/10x are ideal for walking, ornithology, general use etc http://www.eebc.co.uk/productdisplay.aspx?productid=448

71. Vocal Copying Article describing how birds learn their songs from adult tutors and may incorporate sounds from other species into their repertoire. http://www.stanford.edu/group/stanfordbirds/text/essays/Vocal_Copying.html

Vocal Copying M any species of songbirds learn the specific song elements of their repertoires from one or more adult tutors, most often from the male parent. Such learning, for at least some species, is not confined to the period prior to sexual maturity. For example, territorial male Swamp Sparrows listen to songs from adjacent territorial males and incorporate those songs into their own repertoire. Generally, this type of vocal copying, where the individual copied (the model) is a member of the same species, is referred to as "vocal imitation" and serves as the basic mechanism underlying the evolution of dialect systems variation in songs among local populations. SEE: Vocal Dialects Vocal Functions Territoriality Sexual Selection

72. Dr. Susan Willson | St. Lawrence University Academics At SLU, I regularly teach General Biology, Ornithology, General Ecology, Environmental Security, and Tropical Ecology. I have done most of my professional research in Amazonian http://www.stlawu.edu/academics/programs/caribbean-and-latin-american-studies/di

Search this site: Academic Sites caribbean and latin american studies directory Dr. Susan Willson Assistant Professor, Biology Office Email contact form Location: Johnson Science Hall 231 Specific to CLAS, my past and present neotropical research and teaching in Peru, Costa Rica, and Panama, as well as family ties to Ecuador through my husband, keep me well connected to Latin America. I am currently finishing up two manuscripts with former SLU students Alissa Rafferty ‘09 and April Costa ’09 on the ecology of army-ant following birds from my Peru study site. I welcome students who would like to join my lab and have interests in local or tropical birds, army ants, or Latin American conservation issues. I am affiliated with both Caribbean and Latin American Studies (CLAS) and African Studies, as I also work on East African conservation issues. I’m excited to be a part of CLAS as it allows me to interact with students and faculty with a wide range of interests in Latin America, and I welcome students who hope to combine interests from multiple departments. Login to post comments Admissions and Financial Aid First-Year Program Majors and Programs International Studies ... Apply Online Caribbean And Latin American Studies Program Featured Students The Minor Courses Study Abroad ... "Inside the Area"

73. Polygyny Most birds are monogamous, but in some species the occurrence of polygyny, where one male mates with more than one female, is related to high-quality territories with an abundance of resources. http://www.stanford.edu/group/stanfordbirds/text/essays/Polygyny.html

Polygyny P Often that is precisely what is found. For example, female Marsh Wrens near Seattle, Washington, sometimes mate with already-mated males, even when bachelor males are available. The number of females mated to each male is related to the amount of emergent vegetation in the males' territories, which, in turn, is presumably an indicator of the availability of insect food. Studies of Red-winged and Yellow-headed Blackbirds, Dickcissels, Indigo Buntings, and Lark Buntings also show clear relationships between various aspects of territory quality and the likelihood that a male holding a given territory will have more than one mate. Polygyny is not always associated with territoriality. Certain seed-eating savanna species of African weavers (relatives of House Sparrows) have superabundant resources and the males are not territorial, presumably because defending an area does not increase their access to food. The females apparently do not need help from males to raise the young, and the weavers nest in colonies, minimizing the need for a partner in nest defense. The female is thus free to choose any male to father her offspring, regardless of his other attachments. Here, as in situations where males are territorial, polygyny is related to the availability of resources in this case their superabundance rather than their uneven distribution.

74. Staff | Tennessee Tech University Expertise in technical/professional communication; scientific communication; literature and science; literature and the environment; literature and ornithology; general topics on http://www.tntech.edu/pc/staff/

75. Parental Care The young of passerines when first hatched are naked, blind, and helpless and require much care which involves feeding, training and protection from predators. http://www.stanford.edu/group/stanfordbirds/text/essays/Parental_Care.html

Parental Care T he young of most egg-laying reptiles hatch long after the parents have abandoned the eggs; a few lizards and snakes guard them, and pythons incubate their eggs for a while. The young of those female snakes that carry their eggs inside the body until they hatch also receive no parental care. Among reptiles only crocodiles and their relatives tend both eggs and hatchlings. In contrast, nearly all birds provide extended care for their offspring. The exceptions are brood parasites, which foist their responsibility onto other species, and some megapodes, turkey-like birds of the southwest Pacific. Most megapodes scratch together mounds (sometimes astonishingly large) of vegetation or sand and lay their eggs inside. The heat for incubation is provided by decay of the vegetation, the sun, or (occasionally) volcanic activity. Some megapodes tend the mound, opening and closing it to regulate the incubation temperature; others desert the mound. A few megapodes do not build mounds, but simply lay their eggs in warm spots on sand or between rocks and cover them with leaves. Patterns of care in precocial birds (those with young ready to leave the nest almost immediately after hatching) vary a great deal. The major parental duties for most are to keep the young safe from predators and to watch over them as they feed. In many, however, the adults also help instruct the chicks in what's good to eat, how to find it, and how to handle it. Oystercatchers first present food to their young and then train them to find food for themselves. The latter is a long process; oystercatchers specialize in opening mussels and other bivalve mollusks, a difficult task that can be accomplished in less than a minute by an experienced individual, but one that requires many months to learn.

76. MPG - Prof. Dr. P. Berthold Max Planck Institute for Ornithology General Research Interests Until retirement Migration all aspects, annual periodicity, biological rhythms http://www.orn.mpg.de/mitarbeiter/berthold1.html

Personal Information General Research Interests Projects Publications Teaching General Research Interests - Prof. Dr. P. Berthold Max Planck Institute for Ornithology General Research Interests Until retirement: Migration - all aspects, annual periodicity, biological rhythms, behavioural, population and molecular genetics, evolutionary biology, population dynamics, ecosystem analysis, reproduction, biology of capercaillie, basic research related to conservation, satellite tracking Based on my emeritus working place: Various research related to conservation (above all engagement for the establishment of a "Biotopverbund Bodensee" together with the Heinz Sielmann Foundation), migration (satellite tracking studies, preparation of further editions of my book on avian migration), capercaillie biology and conservation, studies of effects of (all year) bird feeding. See as well: Research results (in german)

77. Creches Article describing how some birds adopt the strategy of grouping their young, leaving them with a guardian while both parents go off to forage. http://www.stanford.edu/group/stanfordbirds/text/essays/Creches.html

Creches T he fledglings of some bird species such as Greater Flamingos, Royal and Sandwich Terns, eiders, ostriches, and a number of penguins separate from their parents and form a group, or "creche." Whether parents continue to feed their own chicks, or the chicks feed themselves, supervision of the creche (when it occurs) is usually delegated to a small number of guardians. The guardians, of course, are related to only a small number of the young in the group. It is curious that "altruistic" guarding of unrelated young, presumably a dangerous, tiring responsibility, has evolved. Upon closer scrutiny, however, the behavior is not as altruistic as it appears. Chick-creching generally occurs among birds that breed in large, loose colonies and whose eggs all hatch at about the same time. The day-care system permits a fledgling to lose itself in a crowd and reduce its risk of predation (dilution principle). In the case of young remaining dependent on their parents for food, creching frees the adults to spend more time foraging. Evolutionary theory suggests that creching is likely to develop when the young reared in a gang have a better chance of surviving than those reared alone, so that the birds practicing creche formation contribute more of their genes to the next generation than those that do not form creches.

78. Selected Useful Links Other area colleges and universities may also offer curricula in ornithology. General Birding Links. Birding on the net, by Jack Siler; Bird links of the world, by Denis LePage http://home.xnet.com/~ugeiser/dbc/links.html

Selected Birding Links Recent Sightings Recent postings to IBET , the Illinois birding mail list Illinois Birders Forum by Greg Neise Recent sightings at Fermilab , by Peter Kasper Chicago Area Birding Chicago and Illinois Net-Birding , by Urs Geiser, with many more local and regional links Chicago area birding guide , by Jim Frazier Conservation The DuPage Birding Club is a member of the Chicago area Bird Conservation Network The Chicago Wilderness Habitat Project , including the Illinois Important Bird Areas (IBA). The Purple Martin Society, NA , is directed by a member of the DuPage Birding Club. The Conservation Foundation is a not-for-profit land and watershed protection organization active in DuPage, Kane, Will, and Kendall Counties. The Lake Forest Open Lands Association is a private land trust in northeastern Illinois. Its land holdings include valuable breeding grounds for many uncommon bird species. Locales with Good Birding Fermi National Accelerator Laboratory , near Batavia The Morton Arboretum , in Lisle Forest Preserve District of DuPage County Ornithology Education Locally, it is possible to obtain certificates in ornithology at the following institutions:

79. Bird Milk Article describing how the young of some birds are fed on special secretions from their parents. http://www.stanford.edu/group/stanfordbirds/text/essays/Bird_Milk.html

Bird Milk L ike mammals, the young of some birds are fed on special secretions from a parent. Unlike mammals, however, both sexes produce it. The best known of these secretions is the "crop milk" that pigeons feed to squabs. The milk is produced by a sloughing of fluid-filled cells from the lining of the crop, a thin-walled, sac-like food-storage chamber that projects outward from the bottom of the esophagus. Crops are presumably a device for permitting birds to gather and store food rapidly, minimizing the time that they are exposed to predators. Crops tend to be especially well developed in pigeons and game birds. Crop milk is extremely nutritious. In one study, domestic chicks given feed containing pigeon crop milk were 16 percent heavier at the end of the experiment than chicks that did not receive the supplement. The pigeon milk, which contains more protein and fat than does cow or human milk, is the exclusive food of the nestlings for several days after hatching, and both adults feed it to the squabs for more than two weeks. The young pigeons are not fed insects as are the chicks of many seed-eating birds; instead, the crop milk provides the critical ration of protein. The milk of Greater Flamingos contains much more fat and much less protein than does pigeon milk, and its production is not localized in a crop, but involves glands lining the entire upper digestive tract. Interestingly, the milk contains an abundance of red and white blood cells, which can be seen under the microscope migrating like amoebas through the surface of the glands. Young flamingos feed exclusively on this milk for about two months, while the special filter-feeding apparatus that they will later employ for foraging develops.

80. Jeffrey F. Kelly Taught General Ecology BY220 8/91 - 5/96 Teaching Assistant , Dept. of Biology, Colorado State University Taught laboratories in Vertebrate Biology, Ecology, Ornithology, General http://www.ou.edu/cas/zoology/CVs/kellycv.pdf

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