Pinyon jay (Gymnorhinus cyanocephalus) nest site selection in central New Mexico: Habitat Data to be used with AICc

Pinyon Jays (Gymnorhinus cyanocephalus) are experiencing range wide population declines primarily in response to habitat degradation. Studies examining Pinyon Jay nest site selection in pinyon-juniper woodlands would be helpful in determining potential habitat management prescriptions. Therefore, we conducted a nest site selection study in Pinyon Jay breeding habitat in central New Mexico. We compared size and foliage characteristics of pinyon and juniper trees in 42 17.5-m radius plots around Pinyon Jay nests to 41 same-sized vegetation plots in random locations using binomial generalized linear models. The strongest model indicated that Pinyon Jays preferred nesting in areas with fewer dead juniper trees within pinyon-juniper habitats. Furthermore, Pinyon Jays built nests in pinyon and juniper trees with greater height (p < 0.001) and nests were built below the average tree height in the plot (p = 0.001). Results suggest selective cutting of dead juniper and retention of tall, live pinyon or juniper trees may be used in pinyon-juniper woodlands to improve Pinyon Jay nesting habitat in the western United States.

Methods
This data was collected by measuring the length, width, and height of all vegetation over 1m tall in a 17.5m radius around pinyon jay nests as well as a similar number of randomized locations within pinyon-juniper habitat. Anyone looking to process these data should standardize it, then processes it using AICc in R.

西美松鸦（Pinyon Jay，学名Gymnorhinus cyanocephalus）正经历全分布区的种群数量下降，其主要驱动因素为栖息地退化。针对西美松鸦在松-杜松林地中的巢址选择开展研究，可为制定潜在的栖息地管理方案提供依据。为此，我们在新墨西哥州中部的西美松鸦繁殖栖息地开展了巢址选择研究。我们采用二项式广义线性模型，对比了42个以松鸦巢为中心、半径17.5米的样地内松树与杜松的尺寸及叶片特征，以及41个同等规模的随机位置植被样地。最优模型显示，西美松鸦偏好于松-杜松生境中枯杜松数量更少的区域筑巢。此外，西美松鸦会选择高度更高的松树或杜松筑巢（p < 0.001），且巢位低于样地内的平均树高（p = 0.001）。研究结果表明，在美国西部的松-杜松林地中，可通过选择性砍伐枯杜松、保留高大活松树或杜松的方式，改善西美松鸦的繁殖栖息地。

研究方法
本数据集通过测量松鸦巢周边17.5米半径范围内所有高度超过1米的植被的长度、宽度与高度，以及松-杜松生境内同等数量的随机样地的对应植被参数完成采集。如需处理该数据集，需先对其进行标准化，随后使用R语言中的校正赤池信息准则（AICc）进行分析。