In the western U.S., the black-backed woodpecker has been found to be associated with dense montane conifer forests with high snag densities, typically resulting from moderate- to high-severity wildland fires. However, black-backed woodpeckers are occasionally also detected nesting in unburned forests, raising questions about the type of habitat in which they nest and the potential abundance of such habitat. We conducted intensive black-backed woodpecker nest density surveys in large plots within the middle/upper-montane conifer forests of the Sierra Nevada, California, within general (undisturbed) forests, snag forest habitat from moderate/high-severity wildland fire, and unburned snag forest habitat from drought and native bark beetles. We found black-backed woodpeckers nesting only in the two snag forest conditions, mostly in burned snag forest, and their preferential selection of burned snag forest was statistically significant. No nest was found in general forests. Our spatial analysis indicates that snag forest is rare in the forests of the Sierra Nevada due to fire suppression and logging, raising concerns regarding small population size, which we estimate to be only 461 to 772 pairs in the Sierra Nevada.

中文翻译：

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内华达山脉，加利福尼亚州的黑背啄木鸟巢密度

在美国西部，发现黑背啄木鸟与山毛榉针叶林密密麻麻，密林密度高，通常是中度至高强度的野火所致。然而，黑背啄木鸟有时也被发现在未燃烧的森林中筑巢，这引发了关于它们栖息的栖息地类型以及这种栖息地的潜在丰富性的疑问。我们在加利福尼亚内华达山脉中/上山针叶林，普通（未干旱）森林，中度/高度严重的野火造成的森林栖息地，未燃烧的大片土地上进行了密集的黑背啄木鸟巢密度调查干旱和本地树皮甲虫阻碍森林栖息地。我们发现黑背啄木鸟仅在两个断枝林条件下筑巢，主要是在烧毁的断枝林中，并且他们优先选择烧过的障碍森林有统计学意义。在普通森林中没有发现巢。我们的空间分析表明，由于火势抑制和伐木，断枝林在内华达山脉的森林中很少见，引起了人们对小规模种群的担忧，据估计，内华达山脉只有461至772对。