. Animal Ecology. Animal ecology. FIG. 4-3 Individual ter itori s of birds epr£ senting two ompet- Ing specie s, wood pewee (stippled) and least flycatcher, along a forest trai . Note that te ritor es of indivi dual of the same species do not ov eriap, and that territories of th e tw 0 species are largely but not er tirely exclusive The outline of ach territory is b ased on observatio ns made from the numbered poin ts. The dates of the several dc ta-collection rips are shown for two territories only (Kendeigh 1956). of capturing all individuals present during a trapping period of three nights
. Animal Ecology. Animal ecology. FIG. 4-3 Individual ter itori s of birds epr£ senting two ompet- Ing specie s, wood pewee (stippled) and least flycatcher, along a forest trai . Note that te ritor es of indivi dual of the same species do not ov eriap, and that territories of th e tw 0 species are largely but not er tirely exclusive The outline of ach territory is b ased on observatio ns made from the numbered poin ts. The dates of the several dc ta-collection rips are shown for two territories only (Kendeigh 1956). of capturing all individuals present during a trapping period of three nights (Bole 1939). Influx and de- parture of animals, however, disturbs the accuracy of the measurement. Influx is usually more of a prob- lem than escape from the area, as the trap bait and re- moval of captured individuals encourages invasion (Stickel 1946). Since all animals whose home ranges approach or overlap the boundary of the trapping area are likely to be caught, a correction for this error may be made by considering the census area to in- clude a surrounding belt equal to one-half of the home range of each species concerned (Dice 1952). In order to reduce the boundary of contact with the out- side area to a minimum, square or circular areas are used, rather than rectangular or irregular-shaped areas. Censuses taken in this manner and live-trap censuses sometimes give comparable results (R. M. Wetzel 1949, Buckner 1957), but in neither case can one usually be certain that he has captured all the inhabitants of the area (Fowle and Edwards 1954). Live trapping, marking, and release of individuals is a more trustworthy means of censusing small mam- mals, but is more laborious and time-consuming (Blair 1941, Stickel 1946). Traps are usually dis- tributed grid fashion at intervals of 15 to 20 meters, over several acres or hectares. Trapping is continued for a week, or until very few or no unmarked ani- mals are captured. Marking is commonly toe clip- ping, ear notching, tattooi
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectanimalecology
