The Influence of Multiscale Habitat Variables and Population Density on Artificial Shelter Use by Hellbenders (Cryptobranchus alleganiensis)
The Influence of Multiscale Habitat Variables and Population Density on Artificial Shelter Use by Hellbenders (Cryptobranchus alleganiensis)
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DOI：
10.1655/0018-0831-76.4.355
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发表时间：
2020-12-01
期刊：
影响因子：
2.4
通讯作者：
Hopkins, William A.
中科院分区：
文献类型：
--
作者：
Button, Sky T.;Jachowski, Catherine M. Bodinof;Hopkins, William A.
最近，人工庇护所已被提出作为一种新的工具来监测Hellbenders（隐鳃鲵alleganiensis）和其他隐鳃类蝾螈。影响Hellbenders使用人工庇护所的因素尚未确定，但对于最大限度地利用这些庇护所作为监测工具很重要。为了确定这些因素，在2013-2018年，我们在田纳西河流域上游的三条河流中，在10个由地狱虫居住的河流河段部署了4.38个人工避难所。我们假设，居住和筑巢将取决于庇护所的位置，并且在成年/亚成年地狱虫密度相对较高的区域（即，>1.5个个体/100 m（2））。我们将庇护所安置在代表一系列即时条件的位置，但避免了不适合地狱御术师的微栖息地。我们监测住房占用的地狱虫每2-8周，并调查住所的巢每2-5天在他们的繁殖季节。我们量化的成年/亚成年Hellbenders和10个栖息地变量在多个空间尺度的密度。地狱虫占据了46%的人工避难所，并在17%的人工避难所中筑巢，这些避难所至少有一个繁殖季节。地狱虫最有可能占据和筑巢在避难所放置的部分达到了>= 50厘米深的成年/亚成年个体的高密度。在我们考虑的变量，人口密度是最重要的因素影响庇护所占用的地狱宗。栖息地筑巢受水深影响最大，但也受种群密度和自栖息地安装以来的时间影响。在庇护所部署后，庇护所的占用率和筑巢率都增加了2-3年。我们的研究结果提供的证据表明，人工庇护所构成有效的工具，在一些流监测的发生和繁殖的地狱虫。
Recently, artificial shelters have been proposed as a novel tool to monitor Hellbenders (Cryptobranchus alleganiensis) and other cryptobranchid salamanders. Factors that influence artificial shelter use by Hellbenders have not been identified, but are important for maximizing the utility of these shelters as monitoring tools. To identify these factors, in 2013-2018 we deployed 4.38 artificial shelters across 10 stream reaches inhabited by Hellbenders, within three rivers in the upper Tennessee River Basin. We hypothesized that occupancy and nesting would depend on shelter placement, and would be greatest in reaches with relatively high densities of adult/subadult Hellbenders (i.e., >1.5 individuals per 100 m(2)). We placed shelters in locutions representing a range of instream conditions, but avoided microhabitats that were not suitable for Hellbenders. We monitored shelter occupancy by Hellbenders every 2-8 wk, and surveyed shelters for nests every 2-5 d during their breeding season. We quantified densities of adult/subadult Hellbenders and 10 habitat variables across multiple spatial scales. Hellbenders occupied 46% of artificial shelters, and nested in 17% of artificial shelters that were in place for at least one breeding season. Hellbenders were most likely to occupy and nest in shelters placed in portions of those reaches that were >= 50 cm deep with high densities of adult/subadult individuals. Among the variables we considered, population density was the most important factor influencing shelter occupancy by Hellbenders. Shelter nesting was most influenced by water depth, but also by population density and time since shelter installation. Both occupancy and nesting in shelters increased for 2-3 yr following shelter deployment. Our results provide evidence that artificial shelters constitute efficient tools in some streams for monitoring the occurrence and reproduction of Hellbenders.