Power of Sign Surveys to Monitor Population Trends
نویسندگان
چکیده
منابع مشابه
Power of Sign Surveys to Monitor Population Trends.
The urgent need for an effective monitoring scheme for grizzly bear (Ursus arctos) populations led us to investigate the effort required to detect changes in populations of low-density dispersed animals, using sign (mainly scats and tracks) they leave on trails. We surveyed trails in Glacier National Park for bear tracks and scats during five consecutive years. Using these data, we modeled the ...
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We used pilot data collected in 2001–2004 to compare the power of radar and audiovisual survey approaches to detect trends in breeding population size and differences in trends between populations of marbled murrelets (Brachyramphus marmoratus) in northwestern California. Radar counts of murrelets were almost triple in inland Reserves than in Conservation Areas, and audiovisual counts were 7 ti...
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The Northern Region Landbird Monitoring Program (NRLMP) has been in place for nearly a decade and is designed to allow us to track population trends of numerous landbird species, while at the same time allowing us to investigate the effects of various kinds of land use activity on the occurrence, abundance, or demographics of numerous landbird species. We conduct pointcount bird surveys biennia...
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BACKGROUND A 10-question screening scale of psychological distress and a six-question short-form scale embedded within the 10-question scale were developed for the redesigned US National Health Interview Survey (NHIS). METHODS Initial pilot questions were administered in a US national mail survey (N = 1401). A reduced set of questions was subsequently administered in a US national telephone s...
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I evaluated the use of sign indices as indicators of relative vole population abundances in grasslands and agricultural systems in western Oregon grasslands. The development of a reliable index based on vole sign that does not rely on the repeated use of traps would greatly aid rapid assessment of relative population densities, and allow greater flexibility in both research and management. I te...
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ژورنال
عنوان ژورنال: Ecological Applications
سال: 1992
ISSN: 1051-0761
DOI: 10.2307/1941877