Small mammal movement patterns in an Amur honeysuckle (Lonicera maackii) dominated urban park

Background/Question/Methods

The response of small mammal communities in urban parks to invasion by Amur honeysuckle (Lonicera maackii) is little understood. Urban parks often serve as habitat islands for remnant communities, but this may change when an alien invader is present. Invasive alien plants that enter urban ecosystems and dominate green spaces have a major impact on regional and global biodiversity. Alien invaders have irrevocably altered urban ecosystems across the globe, and biotic homogenization is one major threat in these systems. Amur honeysuckle is a dominant shrub that reduces vegetative biodiversity and can dominate large areas. Here, I look at the effect of Amur honeysuckle on movement patterns and habitat selection of small mammals within an urban park. I conducted a mark-recapture study from summer 2011 to summer 2012 at one site.  The only small mammals captured were Peromyscus spp., and Deer Mouse (Peromyscus maniculatus) and White-Footed Mouse (Peromyscus leucopus) made up 99% of all captures at the site. 

Results/Conclusions

Small mammals (two Peromyscus spp.) were more likely to be captured in areas of higher Honeysuckle density, especially if neighboring areas were flooded. I ran a Multinomial Linear Regression, capture as dependent, Honeysuckle Score (Hscore) and Flood Period (FloodPer) as independents. The model produced an AIC=48.730, likelihood ratio χ²= 18.361 (p=0.010). Males (37 individuals) tended to move more often and move longer distances than females (11 individuals). Hscore is the number of plants on a subplot/ 1,024 m² (size of subplot) multiplied by 100. FloodPer is the average number of time a given subplot was flooded when checked over the course of a year. Preference among small mammals for Amur honeysuckle as a food or shelter resource can play a role in dispersal patterns and community connectivity among urban green spaces. Understanding how small mammals respond to the effects of a wide-spread invader can play an important role in preserving and maintaining regional biodiversity in urban ecosystems.