Variation in collagen stable nitrogen values in black-tailed jackrabbits (Lepus californicus) in relation to small-scale differences in climate,soil, and topography

Longstanding observations about the relationship between increasing aridity and ¹⁵N enrichment in mammalian collagen values have led to an interest in their use as a paleoclimatic marker. Here we report on variability in collagen nitrogen values from five modern and two archaeological samples of black-tailed jackrabbits (Lepus californicus) from the eastern Great Basin of the United States (N = 178 individuals). Nitrogen δ¹⁵N values were highly variable within all samples. Modern samples showed significant differences despite similarities in average annual precipitation and temperature. Archaeological samples were indistinguishable from each other or from modern samples taken from the same area despite independent evidence for differences in precipitation for the two prehistoric periods considered. Differences between modern samples were most strongly associated with soil characteristics. We discuss these results in light of their relationship with topography and vegetation and highlight their implications for archaeological applications of stable nitrogen analyses in several contexts.