Anthropogenic impacts on life history traits on Eastern Chipmunks (Tamias striatus)

Abstract

Urban centers provide unique habitats for opportunistic animal species. However, conditions in urban habitats are inherently stressful and require specialized adaptations in resident animals. Eastern chipmunks are a generalist small rodent species common in a number of different habitat types. I examined differences in behavioural traits and stress levels (chapter one), as well as body condition and parasitism rates (chapter 2) between urban and natural populations of chipmunks. I tested the hypothesis that 1), chipmunks in urban habitats would show greater levels of boldness and exploratory behaviour, 2), urban chipmunks would show greater levels of stress reflected in greater cortisol concentrations in hair and feces, 3) urban chipmunks would have a relatively poor body condition due to poor quality food and competition in urban centers, and 4) urban chipmunks would show greater parasitism rates measured in greater oocyte prevalence, richness, and abundance from fecal samples. A total of 140 individual chipmunks (80 natural and 60 urban) were sampled from natural habitats in Algonquin Provincial Park and outside of Sudbury, and urban habitats in Huntsville and Sudbury Ontario. Differences in behavioural patterns suggest urban animals may be more habituated to human presence, while body condition was significantly superior in urban animals. However, cortisol measured from hair and feces, leukocyte concentrations measured from blood and parasitism impacts did not differ between individuals from the two habitat type. Overall, chipmunks in these urban habitats have a better body condition and are more habituated to human presence than their natural conspecifics.