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Spatiotemporal, Microhabitat, and Climatic Variance in Disjunct Populations of Co-occurring Pinyon-Juniper Woodland Dwelling Chipmunks and Brushmice
Robert M. Sullivan*, William K. Wilson
Robert M. Sullivan
Coastal Ecology and Wildlife Sciences, Coos Bay, OR 97420, USA
robert.m.sullivan@icloud.com
William K. Wilson
P.O. Box 2375 Columbus, NM 88029, USA
william.karl.wilson@gmail.com
Communicated by Chi-Chien Kuo

There is wide-spread agreement that effective management and conservation of assemblages of co-occurring species necessitates baseline studies of spatiotemporal and climatological dynamics underlying community relationships. Such studies are particularly relevant to residual populations of relic species scattered throughout mountainous regions of the North American Southwest. Yet few investigations have examined effects of environmental covariates on disjunct populations of syntopic species in semi-arid woodland or montane forest landscapes. Here we present unpublished “archival” data (1996 ̶1998) from endemic populations of the Colorado chipmunk (Neotamias quadrivittatus) and brushmouse (Peromyscus boylii), which coexist within mature multi-age stands of pinyon-juniper woodland. We evaluated variance in the spatiotemporal regimes of these two species in response to: 1) seasonal area climate, 2) microhabitat use; 3) reproductive output; and 4) estimates of population density. Results of our analysis showed that theoretical density plots and spatial structure of live-trap quadrat data were non-normally distributed for both species. Microhabitat use in each taxon was primarily associated with limestone escarpment-cliff edges and rock outcrops, particularly in chipmunks. Density estimates closely mimicked variance in seasonal climate but with some differences between species. Redundancy analysis showed that drivers of spatiotemporal patterns in these small mammals was predominantly due to seasonal variance in temperature, solar radiation, and humidity during summer, spring, and early fall. Because conservation of mature stands of pinyon-juniper woodlands and relic montane forest represent critical challenges for contemporary and future management of endemic species in these refugial ecosystems, our archival ecological data may facilitate understanding of the dynamics of ecosystem function, uncover legacy effect, and provide a reference for crafting contemporary management and future conservation goals, particularly in the era of rapid climate.

Keywords

American Southwest, Co-occurring, Live-trapped, Relic Species, Small Mammals, Syntopic Species

Supplementary materials
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Citation:

Sullivan RM, Wilson WK. 2026. Spatiotemporal, microhabitat, and climatic variance in disjunct populations of co-occurring pinyon-juniper woodland dwelling chipmunks and brushmice. Zool Stud 65:01.

( Received 23 March 2025 / Accepted 22 December 2025 )