Is the Migratory Behavior of Montane Elk Herds in Peril? The Case of Alberta's Ya Ha Tinda Elk Herd
Is the Migratory Behavior of Montane Elk Herds in Peril? The Case of Alberta's Ya Ha Tinda Elk Herd
复制标题
山地麋鹿群的迁徙行为是否面临危险？
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Tomas E. Hurd
中科院分区：
文献类型：
--
作者：
M. Hebblewhite;E. Merrill;Luigi E. Morgantini;C. White;James R. Allen;Eldon H. Bruns;L. Thurston;Tomas E. Hurd
人们越来越关注全球迁徙有蹄类动物数量的下降。迁徙行为减少的原因可以是直接的（即移徙者的不同收获）或间接的（即生境破碎化或土地利用变化）。麋鹿（Cervus elaphus）是北美重要的大型狩猎物种，其迁徙行为在一些山地生态系统中正在发生变化。我们评估了加拿大最大的麋鹿种群之一Ya Ha Tinda的迁徙行为变化和种群下降的证据和假设。本文比较了1972 ~ 2005年22次冬季和13次夏季直升机调查获得的麋鹿迁徙性与常住性之比（M:R）和季节空间分布。还比较了1977-1980年（早期）和2001-2004年（最近）的辐射颈麋鹿样本的迁徙时间和夏季分布。种群M:R比由前期的12.4 （SD = 3.22）下降到3.0 （SD = 1.63）。根据人口变化，下降幅度大于预期。M:R的下降也反映了放射性项圈麋鹿的行为。2001-2004年间，我们监测到的49%以上的戴无线电项圈的麋鹿全年都居住在冬季栖息地附近，而迁徙者在夏季栖息地停留的时间更少。我们发现，冬季范围的扩大、越冬马获得干草、灰狼（Canis lupus）的重新定居以及麋鹿的管理重新安置与观察到的麋鹿种群增长（根据收获和移除进行调整）和迁徙行为的变化最为一致。然而，我们不能在时间序列人口模型中隔离特定因素的影响。我们认为，需要将迁徙和居住人口与栖息地和死亡率因素直接联系起来，以了解影响该和其他山地麋鹿群迁徙行为的机制。
Abstract There is growing concern that populations of migratory ungulates are declining globally. Causes of declines in migratory behavior can be direct (i.e., differential harvest of migrants) or indirect (i.e., habitat fragmentation or land-use changes). Elk (Cervus elaphus) are an important big game species in North America whose migratory behavior is changing in some montane ecosystems. We evaluated evidence and hypotheses for changes in migratory behavior and population decline in one of Canada's largest elk populations, the Ya Ha Tinda. We compared the ratio of migrant to resident elk (M:R) in the population and seasonal spatial distributions obtained from 22 winter and 13 summer helicopter surveys between 1972 and 2005. Timing of migration and the summer distribution for a sample of radiocollared elk also was compared for 1977–1980 (early period) and 2001–2004 (recent). The population M:R ratio decreased from 12.4 (SD = 3.22) in the early period to 3.0 (SD = 1.63). The decrease was greater than expected based on population change. Declines in M:R also mirrored behavior of radiocollared elk. More than 49% of radiocollared elk we monitored resided near the winter range year-round by 2001–2004, and migrants were spending less time on summer ranges. We found winter range enhancements, access to hay fed to wintering horses, recolonization by gray wolves (Canis lupus), and management relocations of elk were most consistent with observed elk population growth (adjusted for harvest and removals) and the change in migratory behavior. However, we could not isolate the effects of specific factors in time-series population modeling. We believe directly relating migrant and resident demography to habitat and mortality factors will be required to understand the mechanisms affecting migratory behavior in this and other montane elk herds.