Ecological Studies of Wolves on Isle Royale
Ecological Studies of Wolves on Isle Royale
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皇家岛上狼的生态研究
DOI：
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
R. Peterson
中科院分区：
文献类型：
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作者：
S. Hoy;J. Vucetich;R. Peterson
2023年2月，狼的数量可能是31只。这比去年估计的28只狼略有增加（图1）。狼的种群包括一个有11只狼的东部狼群，一个有5只狼的西部狼群，三个至少有3只狼的狼群，以及其他几只狼，它们要么是孤独的，要么只是松散地隶属于其中一个较小的狼群。有证据表明，幼崽在2022年4月出生在三个，可能是四个窝中。根据上下文，2015年至2018年期间没有出生的幼崽。然而，在2018年至2019年期间，狼转移到皇家岛后，2019年出生了一窝，2020年和2021年出生了两窝，2022年可能出生了四窝。因此，在过去的五年里，狼种群的繁殖成功率稳步上升。平均每头狼每月杀死0.52头驼鹿，这是狼获得食物的速度的指标。这一比率略低于去年估计的0.71，但考虑到目前岛上狼和驼鹿的数量，这一比率与预期相似。驼鹿的数量估计为967只，比去年估计的1346只下降了28%。长期的人口趋势表明，驼鹿人口在八年期间（2011-2019）大幅增加，但在过去几年中开始迅速下降。驼鹿种群中新招募个体的比例（即，2月份9个月大的小牛）为1.7%，与长期平均水平相比非常低。捕食率估计为10%，与去年的估计相似，接近长期平均水平。虽然捕食和低招募是驼鹿数量下降的重要原因，但饥饿也起了重要作用。
In February 2023, the wolf population was likely composed of 31 wolves. This is a slight increase from last year’s estimate of 28 wolves (Fig. 1). The wolf population includes an East Pack with 11 wolves, a West Pack with five wolves, three groups of at least three wolves each, and several other wolves that are either loners or only loosely affiliated with one of the smaller groups. There is evidence that pups were born into three, possibly four, litters in April 2022. For context, no litters are thought to have been born between 2015 and 2018. However, following the translocation of wolves to Isle Royale between 2018 and 2019, one litter was born in 2019, two litters were born in both 2020 and 2021, and possibly four litters were born in 2022. Thus, the reproductive success of the wolf population has steadily increased over the last five years. The per-capita kill rate, which is an indication of the rate that wolves acquire food, was 0.52 moose per wolf per month. That rate is somewhat lower than last year’s estimate of 0.71, but similar to what is expected given the number of wolves and moose currently on the island. The estimated abundance of moose is 967, which is a 28 percent decline from last year’s estimate of 1,346. Longer-term population trends suggest that the moose population had increased greatly over an eight-year period (2011-2019) but then started to decline rapidly over the last few years. The proportion of the moose population that is newly recruited individuals (i.e., nine-month-old calves in February) was 1.7 percent, which is very low compared to the long-term average. Predation rate was estimated to be 10 percent, which is similar to last year’s estimate and close to the long-term average. While predation and low recruitment were important contributors to the moose decline, starvation also played an important role.