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Abstract |
Against a background of recovering large carnivore populations in Norway, and many other areas of Europe, it is becoming increasingly important to develop methods to monitor their populations. A variety of parameters can monitored depending on objectives. These parameters include: presence/absense, distribution, population trend indices, minimum counts, statistical estimates of population size, reproductive parameters and health/condition. Three broad categories of monitoring techniques can be recognised each with increasing levels of fieldwork required. The first category includes those techniques that do not require original fieldwork. The second category involves fieldwork, but where individually recognisable carnivores are not available. The third category includes methods where fieldwork has recognisable individuals available. Different mehtods tend to have been used for different species, mainly because of limitations imposed by the different species' ecology. The most precise estimates of population size have been obtained in research projects with relatively small study sites and with the help of radio-telemetry. However, it may be difficult, or impossible, to apply these methods over large monitoring areas. Therefore, in terms of practical management, a combination of minimum counts, supported by an independent index may be more useful than statistical population estimates. All methods should be subject to a careful design process, and power analysis should be conducted to determine the sensitivity of the method to detect changes.
Based on the review of over 200 papers and reports we recommend a package of complementary monitoring methods for brown bear, wolverine, lynx and wolf in Norway. These include the use of observations from the public and reports of predation on livestock to determine broad patterns of distribution, and an index based on hunter observations per hunting day, for all four species. Minimum counts of reproductive units, natal dens, family groups, and packs, should be obtained from snow-tracking for wolverines, lynx and wolves respectively. In addition a track-count index should be obtained for wolverines and lynx. As much data as possible should be obtained of lynx and wolvereines killed in the annual harvest. Brown bears will be difficult to monitor without the use of radio-telemetry, therfore they may require periodic telemetry based, mark-recapture studies. Such a program can easily be constructed within existing central and regional wildlife management structures, but will require extensive involvement from hunters. |
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