Fig 1.
Study area and example study sites.
Study sites were small woodlots (i.e., habitat patches) located in a north-central Indiana, USA, study area. Study sites were selected to represent the degrees of patch isolation found on the landscape, and sites were categorized as low, intermediate, and high connectivity. Low connectivity sites averaged 8.3 ± 4.6% (± 1SE) forest habitat in the surrounding 92 ha of land (where 92 ha represents the average home range size of an adult male raccoon in the study area; Beasley et al. 2011), intermediate connectivity sites averaged 13.5 ± 2.5% forest habitat, and high connectivity sites averaged 32.0 ± 2.0% forest habitat in the surrounding 92 ha. Layers used to create this figure are freely available from the USGS National Map Viewer http://viewer.nationalmap.gov/viewer/.
Table 1.
List of vertebrate scavengers observed feeding on medium-sized carcasses in north-central Indiana, USA.
Three carcass types (N = 60 of each) were deployed in one-month trials from September 2008—August 2009 and monitored with remote cameras. The number of carcasses each species scavenged is noted, and the duration in hours of scavenging by each species follows in parenthesis. Scavengers were scored as unknown in rare instances where the animal was obscured from view in the images.
Table 2.
Frequency of vertebrate scavengers feeding on three different carcass types experimentally placed in study sites exhibiting three categories of patch connectivity.
Frequency of mammalian, avian, or both types of vertebrate scavengers feeding on raccoon, opossum, and rabbit carcasses placed in habitat patches with low, intermediate, and high landscape connectivity in Indiana, USA.
Fig 2.
Centroid locations of local scavenger guild dissimilarity depicted by carcass type and by category of habitat patch connectivity.
Dissimilarity measures were calculated for each carcass based on the presence/absence of species that engaged in scavenging behavior. Spider plots depict factor centroids for (a) carcass type (where RAC = raccoon, OPO = opossum, and PCT = rabbit) and (b) habitat patch connectivity resulting from principal coordinate analysis (PCO) using 1-Sorensen’s index as a measure of dissimilarity.
Fig 3.
Dispersion of local scavenger guild dissimilarity by categories of habitat patch connectivity.
Dispersion of dissimilarity measures calculated from local scavenger guilds that fed on carcasses deployed in patches with high, intermediate, and low levels of habitat connectivity in north-central Indiana, USA.
Table 3.
Vertebrate scavengers that opened three carcass types.
Frequency of scavengers that opened three different types of carcasses in study sites in Indiana, USA. The scavenger that opened a carcass was scored as unknown (likely a vertebrate) in rare instances where the camera images were inconclusive as to the species’ identity.
Fig 4.
Linear relationship between carcass removal and richness of local vertebrate scavenger guild.
Proportion of carcass consumed by the end of 1-month trials related to local vertebrate scavenger guild richness at each carcass. Hashed lines represent random intercepts for each season based on a linear mixed effect model. The solid line represents the fixed effect (estimate ± 1SE = 0.0597 ± 0.0170).