Whiskers in the Storm: Exploring the Rollercoaster of Disturbances Impacting Small Mammal Populations

Abstract

Our understanding of how disturbances influence small mammal communities is vital given their role as seed predators and dispersers, intermediate hosts for disease vectors, and as prey for higher trophic levels. We must consider landscape-level disturbance, both natural and anthropogenic, as well as habitat management practices to ensure resilient ecosystems. Disturbances can negatively impact small mammal populations. Studies have shown that deforestation, urbanization and silvicultural practices (harvesting) can reduce diversity and abundances of small mammals in favor of the common deer (Peromyscus maniculatus) and white-footed mice (P. leucopus). In fall 2023, we conducted a small mammal survey across a gradient of disturbance, specifically wildfire (Altona Flat Rock 2018), silviculture (harvesting in Ellenburg Depot), and urbanization (City of Plattsburgh industrial park) and paired these sites with adjacent undisturbed reference sites in northern NY. We hypothesized that there would be greater diversity and abundances in small mammal populations at the undisturbed sites. To test this hypothesis, we performed weekly monitoring of Sherman traplines in all sites and performed mark recapture, as well as collected metrics such as weight, gender, and body and tail length. The greatest abundance of small mammals was found within the silviculture harvested site. Long-term monitoring at the Altona Flat Rock suggests that small mammal abundance has been declining since the 2018 wildfire. A species common to all sites was Peromyscus sp., a red-backed vole (Myodes rutilus) and an eastern chipmunk (Tamias striatus) were found in the unharvested and unburned sites, respectively. No animals were present at the urban disturbed site. There was a significant difference in weight among Peromyscus sp. across sites, but not length indicating differences in habitat quality. Apart from the urban site, all disturbed sites possessed the greatest small mammal abundance and their paired undisturbed sites the greatest diversity. There are additional explanations for these results besides disturbance, in particular regional tree masting cycles, which provide a reliable seed source for granivores could be contributing. Understanding how disturbances affect small mammals is essential for biodiversity conservation. Monitoring small mammals can provide early warnings about environmental issues and disturbances, helping researchers and conservationists respond to potential problem.