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Avian Ecology Field Methods
There are many field methods available for conducting avian ecological research. They can be divided into three types: counts, nest monitoring, and capturing and marking. Basic counts Basic bird counts are a good way to estimate population size, detect changes in population size or species diversity, and determine the cause of the changes if environmental or habitat data is collected as well. Basic bird counts can be completed fairly easily and inexpensively, and they provide general information about the status of a bird population. Birds can be directly counted on breeding colonies, and at roosts, flocks, or Leks. Large diurnal migrants, like many raptors, can be counted as they pass through migration bottlenecks. Small nocturnal migrants are harder to count, but many advances have been made in the use of radar and microphone arrays to identify and count them. Point counts and area searches Perhaps the simplest method of counting birds is called a "point count", in which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth Rate
The birth rate for a given period is the total number of live human births per 1,000 population divided by the length of the period in years. The number of live births is normally taken from a universal registration system for births; population counts from a census, and estimation through specialized demographic techniques. The birth rate (along with mortality and migration rates) is used to calculate population growth. The estimated average population may be taken as the mid-year population. Natality is another term used interchangeably with 'birth rate'. When the crude death rate is subtracted from the crude birth rate (CBR), the result is the rate of natural increase (RNI). This is equal to the rate of population change (excluding migration). The total (crude) birth rate (which includes all births)—typically indicated as births per 1,000 population—is distinguished from a set of age-specific rates (the number of births per 1,000 persons, or more usually 1,000 femal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tucson Bird Count
The Tucson Bird Count (TBC) is a community-based program that monitors bird populations in and around the Tucson, Arizona, United States metropolitan area. With nearly 1000 sites monitored annually, the Tucson Bird Count is among the largest urban biological monitoring programs in the world. Methods Each spring, TBC participants collect data on bird abundance and distribution at hundreds of point count locations arrayed across the Tucson basin. The TBC is an example of citizen science, drawing on the combined efforts of hundreds of volunteers. So that data are of suitable quality for scientific analysis and decisionmaking, all TBC volunteers are skilled birdwatchers; many are also professional field guides or biologists. TBC methods are similar to those employed by the North American Breeding Bird Survey, although the TBC uses more closely spaced sites (one site per 1-km2 square) over a smaller total area (approximately 1000 km2). For full details of TBC methods, see the TBC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The EBCC Atlas Of European Breeding Birds
''The EBCC Atlas of European Breeding Birds - their distribution and abundance'' () is an ornithological atlas published for the European Bird Census Council by T & A D Poyser in 1997. Its editors were Ward J. M. Hagemeijer and Michael J. Blair. The atlas was the first to present grid-square distribution maps for all breeding birds at a Europe-wide level. The bulk of the book is in English, although it also contains introductions in thirteen other European languages. The atlas presents the results of the European Bird Census Council's European Ornithological Atlas project, the fieldwork for which was carried out between 1985 and 1988. The book The book has cxli + 903 pages. Its Foreword (by Karel H Voous) and Preface (by Goetz Rheinwald and Jeremy Greenwood) are followed by an English introduction and shorter introductions in Czech, German, Spanish, French, Finnish, Greek, Hungarian, Italian, Dutch, Portuguese, Polish, Russian and Swedish; indexes of bird names, in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabird Colony Register
The Seabird Colony Register (SCR) is a database, managed by the British Joint Nature Conservation Committee, which contains counts of breeding seabirds at British seabird colonies made between 1969 and 1998, which is used for analysing past changes in breeding seabird numbers and changes in their colony size in Britain and Ireland. Data included in the SCR include results of two complete seabird censuses of Britain and Ireland: Operation Seafarer (1969/70) and the Seabird Colony Register Census (1985–1987), as well as ad hoc counts and counts from other surveys. Data are held for all 25 species of seabird breeding throughout Britain and Ireland. The SCR has been partially superseded by the Seabird 2000 Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ... database. References * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christmas Bird Count
The Christmas Bird Count (CBC) is a census of birds in the Western Hemisphere, performed annually in the early Northern-hemisphere winter by volunteer birdwatchers and administered by the National Audubon Society. The purpose is to provide population data for use in science, especially conservation biology, though many people participate for recreation. The CBC is the longest-running citizen science survey in the world. History Up through the 19th century, many North Americans participated in the tradition of Christmas "side hunts", in which they competed at how many birds they could kill, regardless of whether they had any use for the carcasses and of whether the birds were beneficial, beautiful, or rare. In December 1900, the U.S. ornithologist Frank Chapman, founder of Bird-Lore (which became Audubon magazine), proposed counting birds on Christmas instead of killing them. On Christmas Day of that year, 27 observers took part in the first count in 25 places in the Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Bird Count
The Australian Bird Count (ABC) was a project of the Royal Australasian Ornithologists Union (RAOU). Following the first and successful Atlas of Australian Birds project, which led to the publication of a book on the distribution of Australian birds in 1984, it was suggested by Ken Rogers (ornithologist), Ken Rogers that the RAOU should next look at bird migration and other movements in Australia. Methodology for a suitable project involving volunteers was worked out through experimental fieldwork and a workshop on ‘Monitoring the Populations and Movements of Australian Birds’. A project manager, [Stephen Ambrose], was appointed and project fieldwork ran from January 1989 to August 1995. Some 950 volunteer observers carried out 79,000 surveys, for fixed 20-minute periods in 1700 three-hectare locations over Australia. Project management started at the Australian Museum in Sydney and was later moved to the RAOU National Office in Melbourne. Financial support came at first fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patagium
The patagium (plural: patagia) is a membranous body part that assists an animal in obtaining lift when gliding or flight. The structure is found in extant and extinct groups of flying and gliding animals including bats, birds, some dromaeosaurs, pterosaurs, gliding mammals, some flying lizards, and flying frogs. The patagium that stretches between an animal's hind limbs is called the uropatagium (especially in bats) or the interfemoral membrane. Bats In bats, the skin forming the surface of the wing is an extension of the skin of the abdomen that runs to the tip of each digit, uniting the forelimb with the body. The patagium of a bat has four distinct parts: #Propatagium: the patagium present from the neck to the first digit. #Dactylopatagium: the portion found within the digits. #Plagiopatagium: the portion found between the last digit and the hindlimbs. #Uropatagium: the posterior portion of the flap between the two hindlimbs. Pterosaurs In the flying pterosaurs, the patag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mist Net
Mist nets are used by hunters and poachers, but also by ornithologists and chiropterologists to capture wild birds and bats for banding or other research projects. Mist nets are typically made of nylon or polyester mesh suspended between two poles, resembling a volleyball net. When properly deployed in the correct habitat, the nets are virtually invisible. Mist nets have shelves created by horizontally strung lines that create a loose, baggy pocket. When a bird or bat hits the net, it falls into this pocket, where it becomes tangled. The mesh size of the netting varies according to the size of the species targeted for capture. Mesh sizes can be measured along one side of the edge of a single mesh square, or along the diagonal of that square. Measures given here are along the diagonal. Small passerines are typically captured with 30–38 mm mesh, while larger birds, like hawks and ducks, are captured using mesh sizes of ~127 mm. Net dimensions can vary widely depending ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate and inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fledge
Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable condition in the nest, the nestling and fledging stage can be the same. For precocial birds, those that develop and leave the nest quickly, a short nestling stage precedes a longer fledging stage. All birds are considered to have fledged when the feathers and wing muscles are sufficiently developed for flight. A young bird that has recently fledged but is still dependent upon parental care and feeding is called a fledgling. People often want to help fledglings, as they appear vulnerable, but it is best to leave them alone. The USA National Phenology Network defines the phenophase (or life cycle stage) of fledged young for birds as "One or more young are seen recently departed from the nest. This includes young incapable of sustained fli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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