2.1 | Study area
We investigated raccoon temporal dynamics across differing levels of coyote activity at four sites across the state of Michigan, USA (Figure 2) which represent an urban-rural gradient.
1) The Huron Mountain Club (HMC) is a privately-owned property along the southern shore of Lake Superior, encompassing around 6,900 hectares in Marquette County, Michigan, USA. This site has a wide variety of habitats including beech-sugar maple hardwood forests, aspen dominated stands, and coniferous boreal forests. Sympatric large predators include: gray wolves, black bears (Ursus americanus ), and coyotes. Anthropogenic pressures are limited to a small, seasonally occupied area of human habitation near the north central part of the property. Hunting and fishing occur on the property, and the intensity is presumably low due to restrictive public access.
2) The University of Michigan Biological Station (UMBS), a ~4,000 hectare research station and forest in Pellston County, Michigan, USA served as one of our intermediate disturbance sites. With repeated logging and fire disturbance until 1923, the secondary forest is a mix of transitional hardwood and boreal forests. Douglas and Burt lakes along the north and south, and the town of Pellston and a major highway along west and east, respectively border this study area. Large co-occurring predators include: black bears, coyotes, and coyote-wolf hybrids. We were able to distinguish the few known coyote-wolf hybrids in the area due to them having collars from a different study, which were visible in the camera trap images (Wheeldon et al. 2012). Human pressures resulted from regulated research infrastructures for climate monitoring and housing facilities with low levels concentrated seasonally during the summer.
3) The Shiawassee National Wildlife Refuge (SNWR) is a 9,870 hectare wildlife refuge managed by the US Fish and Wildlife Service. The refuge is comprised of forested hardwood wetlands and lakeplain prairie. The city of Saginaw abuts the northern edge of the refuge and is surrounded by agricultural land for crop farming. The only large native predator present is the coyote. Anthropogenic pressures, in addition to the urban and ex-urban nature of the boundaries, are in the form of recreational visitors. Public hunting for deer and waterfowl, and furbearer trapping are permissible on the refuge in accordance with lawful seasons.
4) The Detroit Metro Parks (DMP) is a collection of greenspaces interspersed throughout southeast Michigan that is managed by the Detroit Parks and Recreation Department. We chose twenty-five of these parks that varied in size from ~1.6-480 hectares, tree cover, human visitation, and degree of disturbance. Roads, buildings, or a riverine edge bound all parks. The only large native predator present is the coyote. Strong anthropogenic pressures are present in the form of the surrounding urban matrix, as well as the associated presence of humans and domestic pets across parks