Pitfall versus Live-Trap Enumeration of Fluctuating Populations of Microtus townsendii

摘要: Four populations of Microtus townsendii were trapped concurrently with live-traps and pitfall traps from May 1976 until June 1978. The number voles enumerated by in both increasing peak was up to two times larger than the live-traps. Pitfall generally caught under 40 g, over g. About 45% 3,677 captured first never Among those subsequently entering livetraps, 50% stayed away for more 5 weeks, 10% 20 weeks. previously animals that dispersed did livetraps. An index juvenile survival based on data derived may not be indicative actual trends. Voles only have faster growth rates later Live-traps sample different segments population respect size, wounding levels, parasite loads.