PITFALL VERSUS LIVE-TRAP ENUMERATION OF FLUCTUATING POPULATIONS OF MICROTUS-TOWNSENDII
PITFALL VERSUS LIVE-TRAP ENUMERATION OF FLUCTUATING POPULATIONS OF MICROTUS-TOWNSENDII
复制标题
DOI：
10.2307/1379842
复制
发表时间：
1980-01-01
影响因子：
1.7
通讯作者：
KREBS, CJ
中科院分区：
文献类型：
--
作者：
BEACHAM, TD;KREBS, CJ
四个种群的M.从1976年5月至1978年6月，用活捕器和陷阱诱捕townsendii。在增加和高峰人口的陷阱陷阱枚举的田鼠的数量是2倍以上的生活陷阱枚举的数量。陷阱一般捕捉40 g以下的田鼠，活陷阱一般捕捉40 g以上的田鼠。约45%的3677田鼠首次捕获的陷阱陷阱从来没有捕获的生活陷阱。在随后进入诱捕器的田鼠中，超过50%的田鼠离开诱捕器超过5周，10%的田鼠离开诱捕器超过20周。以前，陷阱捕捉到的动物比活陷阱多。根据捕兽器数据得出的幼鱼存活指数可能并不表明实际趋势。仅在陷阱中捕获的田鼠比首先在陷阱中捕获的田鼠和后来在活陷阱中捕获的田鼠具有更快的生长速率。活捕集器和陷阱捕集器根据大小、受伤程度和寄生虫负荷对种群的不同部分进行采样。
Four populations of M. townsendii were trapped with live-traps and pitfall traps from May 1976 until June 1978. The number of voles enumerated by pitfall traps in both increasing and peak populations was up to 2 times larger than the number enumerated by live-traps. Pitfall traps generally caught voles under 40 g, live-traps over 40 g. About 45% of 3677 voles captured first by pitfall traps were never caught by live-traps. Among those voles subsequently entering live-traps, over 50% stayed away for more than 5 wk, and 10% stayed away for more than 20 wk. Pitfall traps previously caught more animals that dispersed than did live-traps. An index of juvenile survival based on data derived from live-traps may not be indicative of actual trends. Voles caught only in pitfall traps have faster growth rates than those first caught in pitfall traps and later in live-traps. Live traps and pitfall traps sample different segments of the population with respect to size, wounding levels and parasite loads.