Sex and age-specific differences in the performance of harvest indices as proxies of population abundance under selective harvesting

IF 1.7 3区生物学 Q3 ECOLOGY

Wildlife Biology Pub Date : 2020-08-19 DOI:10.2981/wlb.00629

Pauline Priadka, Glen S. Brown, B. Patterson, F. Mallory

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引用次数: 6

Abstract

Harvest indices are commonly used as proxies to direct population monitoring but sources of variability, including harvest effort and factors influencing detectability of animals to hunters, are rarely considered. Harvest indices may further be influenced by selective harvesting with regulatory differences in harvest effort across sex and age-classes. To evaluate how sex and age-specific harvests vary as proxies of abundance under selective harvesting, we assessed harvest–abundance relationships (H–A) for moose Alces alces bulls, cows and calves across 58 wildlife management units (WMUs) in Ontario, Canada. Selective harvesting in our study area resulted in more regulated harvest of bulls and cows than calves. We therefore predicted more proportional H–A for calves than bulls and cows, with variability in H–A influenced by harvest effort, in addition to weather and landscape features that may influence moose detectability to hunters. In contrast to our expectation, we found that H–A was more proportional for adult moose than calves. Additionally, we found harvest was proportionally highest for bulls, despite greater harvest effort for calves. A positive effect of harvest effort on harvest as moose abundance increased helped to explain proportional H–A for adult moose. However, the effect of harvest effort on harvest was curvilinear at high effort levels, indicating that harvest will underestimate abundance when effort by hunters is high. Additionally, we found evidence of lower harvest in relation to abundance in WMUs with higher levels of recent disturbance from wildfire burns and clear-cuts. We demonstrate that the relationship between harvest and abundance can vary across selectively harvested sex and age-classes, while variability in H–A can be attributed to spatial variability in harvest effort and the landscape. We caution that sources of variability in H–A, both across and among sex and age-classes, should not be ignored when using harvest indices, especially for selectively harvested species.

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在选择性收获下，作为种群丰度指标的收获指数表现的性别和年龄差异

收获指数通常被用作直接监测种群的指标，但很少考虑变异性的来源，包括收获努力和影响猎人发现动物的因素。收获指数可能进一步受到选择性收获的影响，不同性别和年龄阶层的收获努力存在调节差异。为了评估特定性别和年龄的收获作为选择性收获下丰度的指标是如何变化的，我们评估了加拿大安大略省58个野生动物管理单位（WMU）的驼鹿Alces Alces公牛、奶牛和小牛的收获-丰度关系（H–A）。在我们的研究区域，选择性收获导致公牛和奶牛的收获比小牛更受监管。因此，我们预测，与公牛和奶牛相比，小牛的H–A比例更高，H–A的变化受到收获努力的影响，此外，天气和景观特征可能会影响猎人对驼鹿的检测能力。与我们的预期相反，我们发现成年驼鹿的H-A比小牛的比例更大。此外，我们发现，尽管小牛的收获努力更大，但公牛的收获比例最高。随着驼鹿数量的增加，收获努力对收获的积极影响有助于解释成年驼鹿的比例H-A。然而，在高努力水平下，收获努力对收获的影响是曲线的，这表明当猎人的努力高时，收获会低估丰度。此外，我们发现了与WMU丰度相关的较低收获的证据，最近野火燃烧和清理造成的干扰水平较高。我们证明，收获和丰度之间的关系可能因选择性收获的性别和年龄类别而异，而H–A的变异可归因于收获努力和景观的空间变异。我们警告说，在使用收获指数时，不应忽视不同性别和年龄阶层之间H–A变异的来源，尤其是对于选择性收获的物种。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Wildlife Biology 生物-动物学

CiteScore

4.30

自引率

0.00%

发文量

审稿时长

>12 weeks

期刊介绍： WILDLIFE BIOLOGY is a high-quality scientific forum directing concise and up-to-date information to scientists, administrators, wildlife managers and conservationists. The journal encourages and welcomes original papers, short communications and reviews written in English from throughout the world. The journal accepts theoretical, empirical, and practical articles of high standard from all areas of wildlife science with the primary task of creating the scientific basis for the enhancement of wildlife management practices. Our concept of ''wildlife'' mainly includes mammal and bird species, but studies on other species or phenomena relevant to wildlife management are also of great interest. We adopt a broad concept of wildlife management, including all structures and actions with the purpose of conservation, sustainable use, and/or control of wildlife and its habitats, in order to safeguard sustainable relationships between wildlife and other human interests.