Birds Of A Feather Wallpaper Biography
One approach to detecting the existence of competitive interactions in bird communities is to determine whether closely related species are distributed independently over a large sample of similar habitats, or whether the presence of one or more species has an influence on the others. For four years, ecologists Catherine Toft, David Trauger, and Horatio Murdy analyzed statistically the distribution of five duck species breeding in 236 ponds in the Northwest Territories of Canada. Three of the ducks were dabblers: Mallard, American Wigeon, and Green-winged Teal. Two were divers: Lesser Scaup and Ring-necked Duck. The species showed significant differences in both time of hatching and pond-size use. For instance, the dabblers nested early, running the risks of springtime inclement weather. The divers nested later, risking the loss of their broods with the arrival of the fall freeze. Mallards showed little preference for pond size, teal strongly preferred small ponds, and wigeon and divers preferred large ponds (and were almost never found in small ones). Detailed analysis of the results led to the conclusion that competition, past and present, was responsible for patterns of pond use, and partially responsible for the temporal differences in dabbler and diver breeding. The most dramatic current competition was between the two divers; the scaup and Ring-necks would often occupy the same pond in different years, but not occur there together.
One approach to detecting the existence of competitive interactions in bird communities is to determine whether closely related species are distributed independently over a large sample of similar habitats, or whether the presence of one or more species has an influence on the others. For four years, ecologists Catherine Toft, David Trauger, and Horatio Murdy analyzed statistically the distribution of five duck species breeding in 236 ponds in the Northwest Territories of Canada. Three of the ducks were dabblers: Mallard, American Wigeon, and Green-winged Teal. Two were divers: Lesser Scaup and Ring-necked Duck. The species showed significant differences in both time of hatching and pond-size use. For instance, the dabblers nested early, running the risks of springtime inclement weather. The divers nested later, risking the loss of their broods with the arrival of the fall freeze. Mallards showed little preference for pond size, teal strongly preferred small ponds, and wigeon and divers preferred large ponds (and were almost never found in small ones). Detailed analysis of the results led to the conclusion that competition, past and present, was responsible for patterns of pond use, and partially responsible for the temporal differences in dabbler and diver breeding. The most dramatic current competition was between the two divers; the scaup and Ring-necks would often occupy the same pond in different years, but not occur there together.
Birds Of A Feather Wallpaper
Birds Of A Feather Wallpaper
Birds Of A Feather Wallpaper
Birds Of A Feather Wallpaper
Birds Of A Feather Wallpaper
Birds Of A Feather Wallpaper
Birds Of A Feather Wallpaper
The ZOO Movies PELICANS Video - PELICANUS OCCIDENTALIS
Birds - 9th May 2011
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