Distribution and Postbreeding Environmental Relationships of Northern Leopard Frogs (Rana [Lithobates] Pipiens) in Washington
Distribution and Postbreeding Environmental Relationships of Northern Leopard Frogs (Rana [Lithobates] Pipiens) in Washington
复制标题
华盛顿州北部豹蛙（Rana [Lithobates] Pipiens）的分布和繁殖后环境关系
DOI：
10.3398/064.069.0413
复制
发表时间：
2009
影响因子：
5.9
通讯作者：
D. Hays
中科院分区：
文献类型：
--
作者：
S. Germaine;D. Hays
摘要。北方豹蛙（Rana [Lithobates] pipiens）在所有西部各州和加拿大西部省份都被认为是敏感的、受威胁的或濒危的。豹蛙历史上出现在华盛顿东部的6个主要河流流域，现在只知道出现在格兰特县螃蟹溪流域的2个局部地区。在2002年至2005年的夏天，我们调查了这两个地区的豹蛙分布的程度，并描述栖息地和脊椎动物群落特征与豹蛙网站占用。在Gloyd Seeps，在沿着5公里的河段共观察到2只幼年豹蛙，搜索时间为8.2人日。在Potholes水库，我们调查了243个湿地网站在7个管理单位已知已被豹蛙在20世纪80年代。我们确认豹蛙的存在，只有87个网站（36%）在4个管理单位。个别池塘的网站占用模型表明，无人居住的网站相比，占用网站稍大的池塘深度，不高的紧急植被，草本植被覆盖，和更少的邻近池塘含有非本地捕食性鱼类。在1平方公里的规模开发的模型表明，占领区有更大的平均仲夏池塘深度，较少的池塘被牛蛙（蛙[Lithobates] catesbeiana）和鲤鱼（鲤鱼），和更多的草本植物周围的池塘。Gloyd Seeps的人口现在似乎已经不复存在，而Potholes水库的人口正在急剧下降。除非采取管理措施减少外来鱼类和牛蛙，并加强湿地植被，否则豹蛙可能很快就会从这两个地点灭绝，因此可能会从华盛顿灭绝。
ABSTRACT. Northern leopard frogs (Rana [Lithobates] pipiens) are considered sensitive, threatened, or endangered in all western states and western Canadian provinces. Historically present in eastern Washington in 6 major river drainages, leopard frogs are now only known to occur at 2 localized areas in the Crab Creek drainage in Grant County. During the summers of 2002–2005, we surveyed both areas to document extent of leopard frog distributions and to describe habitat and vertebrate community characteristics associated with leopard frog site occupancy. At Gloyd Seeps, 2 juvenile leopard frogs were observed in a total of 8.2 person-days of searching along a 5-km stream reach. At Potholes Reservoir, we surveyed 243 wetland sites in 7 management units known to have been occupied by leopard frogs during the 1980s. We confirmed leopard frog presence at only 87 sites (36%) in 4 management units. Site occupancy models for individual ponds indicated that, compared to unoccupied sites, occupied sites had slightly greater pond depths, less tall emergent vegetation, more herbaceous vegetative cover, and fewer neighboring ponds containing nonnative predatory fish. Models developed at the 1-km2 scale indicated that occupied areas had greater average midsummer pond depths, fewer ponds occupied by bullfrogs (Rana [Lithobates] catesbeiana) and carp (Cyprinus carpio), and more herbaceous vegetation surrounding ponds. The Gloyd Seeps population now appears defunct, and the Potholes Reservoir population is in sharp decline. Unless management actions are taken to reduce nonnative fish and bullfrogs and to enhance wetland vegetation, leopard frogs may soon be extirpated from both sites and possibly, therefore, from Washington.