# Seasonal Variation in Mammalian Mesopredator Spatiotemporal Overlap on a Barrier Island Complex

## TL;DR

This study examines how three medium-sized predators in a barrier island complex adjust their activity and habitat use seasonally, affecting their interactions and potentially impacting nesting birds and turtles.

## Contribution

The study reveals seasonal shifts in spatiotemporal overlap among mesopredators in a human-impacted barrier island ecosystem.

## Key findings

- During the wet season, coyotes, raccoons, and opossums showed increased spatiotemporal overlap.
- In the dry season, these species partitioned their temporal niches, reducing overlap and with opossums using mangrove habitats more.
- The park's developed nature may have destabilized mesopredator dynamics, affecting vulnerable prey like nesting birds and turtles.

## Abstract

In human-dominated areas where top predators no longer occur, interactions among medium-sized predators can be complex, especially when considering how they share space and time based on seasonal changes in food and habitat. We studied this using camera traps placed in various habitats from February 2021 to July 2023, at Fort De Soto County Park, a barrier island complex located in west central Florida. Three species of mammals (coyotes, raccoons, and Virginia opossums) were the most frequently photographed. Our analysis showed that during the wet season, these species were most likely to be photographed in similar habitats and times. During the dry season, when perhaps there were fewer food sources, the species shifted when they were active in a manner that created less overlap. Also in the dry season, opossums made more use of mangrove habitats. Understanding the relationships among these species is important because this area supports nesting shorebirds and sea turtles, known prey for these predators.

Due to lack of apex predators in human-dominated landscapes, mesopredator relationships are complex and spatiotemporal niche partitioning strategies can vary, especially when seasonal shifts in resource availability occur. Our objective was to understand spatiotemporal niche overlap across seasons among mesopredators inhabiting a barrier island complex. We placed 19 unbaited cameras throughout Fort De Soto County Park, Florida, USA between February 2021 and July 2023. Of six mesopredator species detected, three species had >75 detections during both the wet and dry seasons (coyote, Canis latrans; Virginia opossum, Didelphis virginiana; and raccoon, Procyon lotor). Using general linear mixed models, we determined that during the wet season coyote–raccoon and raccoon–opossum detections were positively associated with each other (p < 0.05). During the dry season, raccoon–opossum detections were positively associated, and opossums were more likely to be detected around mangroves. After calculating coefficients of overlap, we found all three species varied their temporal activity between seasons. During the dry season exclusively, all three mesopredators occupied different temporal niches. The park’s isolated but developed nature has potentially led to a destabilized mesopredator community. Understanding seasonal mesopredator dynamics of Fort De Soto is particularly important because this park supports a high number of nesting shorebirds and sea turtles, which are known food sources for mesopredators.