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The remote sensing approach to censusing
Author(s) -
Marten Gerald G.
Publication year - 1972
Publication title -
population ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 59
eISSN - 1438-390X
pISSN - 1438-3896
DOI - 10.1007/bf02511184
Subject(s) - marten , library science , citation , service (business) , population , ecology , resource (disambiguation) , geography , sociology , biology , habitat , computer science , demography , computer network , economy , economics
Population censusing continues to be a methodological problem in ecology, particularly for inconspicuous, mobile animals which are spaced over a large area. Whereas most censusing has depended upon capturing such animals, an approach based upon sampling without capture may serve better in many situations. The advantages of non-capture censusing, as reviewed in detail by MARTEN (in press a), are that: (1) The population is sampled with a minimum of disturbance. (2) Multiple sampling of each individual in the population generates samples large enough for precise estimates, even with difficult-to-trap species or low population densities. (3) Sampling bias, so common with trapping, may be avoided. (4) Population density is measured directly, making unnecessary a computed boundary strip to determine the area censused. (5) Measurement of density has high resolution in time and space. MARTEN (in press a) has already applied the non-capture approach in censusing deer mice (Peromyscus), sampling by means of tracks on smoked cards. The basic principle of mark-recapture was employed, where the proportion of known, marked mice in the total population was reflected simply in the proportion of all tracks which were marked. Presented below is a feasibility study of non-capture sampling by means of electronic remote sensing. Deer mice are detected by electronic cables lying on the ground, which register whenever a mouse crosses anywhere along their length. It is supposed that, for a given level of activity, the amount of cable-crossing by mice is proportional to the average density of occupancy along the length of the cables. This should apply regardless of the particular spatial configuration of the cables, whether they are along a single line or concentrated in one area. Such cables effectively exploit the potential advantages of non-capture sampling: (1) The sample size from lines is greater than from discrete points. A mouse can avoid discrete detection points, but it must cross lines if it moves