Wild Canid Distribution and Co-Existence in a Natural–Urban Matrix of the Pioneer Valley of Western Massachusetts
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20192019 NORTHEASTERNNortheastern Naturalist NATURALIST 26(2):325–342Vol. 26, No. 2 E.G. LeFlore, T.K. Fuller, J.T. Finn, S. DeStefano, and J.F. Organ Wild Canid Distribution and Co-existence in a Natural–Urban Matrix of the Pioneer Valley of Western Massachusetts Eric G. LeFlore1, Todd K. Fuller1,*, John T. Finn1, Stephen DeStefano2, and John F. Organ3 Abstract - Although development and urbanization are typically believed to have negative iMpacts on carnivoran species, soMe species can successFully navigate an urban Matrix. Sympatric carnivorans compete for limited resources in urban areas, likely with system- specifc impacts to their distributions and activity patterns. We used automatically triggered wildlife cameras to assess the local distribution and co-existence of Canis latrans (Coyote), Vulpes vulpes (Red Fox), and Urocyon cinereoargenteus (Gray Fox) across the Pioneer Valley, MA, in relation to different levels of human development. We placed cameras at 79 locations in Forested, altered, and urban land-use areas FroM SepteMber to NoveMber 2012 and accumulated 1670 trap nights. We determined site characteristics and detection rates For 12 other wildliFe species For each caMera location to develop a generalized linear model for the local distribution of each focal canid species across the study area. We also coMpared diel activity patterns aMong Coyotes, Red Foxes, and Gray Foxes, and calculated coeffcients of overlap between each pair. The local distribution of Coyotes was positively associated with the detection rates oF their prey and not associated with detection rates of syMpatric carnivoran species. Red Foxes and Gray Foxes had negative relationships with the detection rate oF Coyotes, and none oF the 3 canid species showed a positive correlation with increased levels of urbanization. There was a high degree of temporal overlap in diel activity patterns and liMited spatial overlap oF our Focal species, which suggests that any competition avoidance across our study area occurred at the spatial level. Coyotes fll the role of top predator in the Pioneer Valley, and likely have a negative impact on the local distributions oF sMaller canids, while their own local distributions seeM to be driven by prey availability. Introduction Urbanization has FragMented, degraded, and eliMinated natural landscapes (Marzluff 2001). This process, in turn, impacts wildlife in urban and adjacent ar- eas (Gehrt 2010), causing changes in aniMal MoveMents (Villaseñor et al. 2014), behaviors (Riley et al. 2003), density (Chernousova 2001), and distribution (Bon- nington et al. 2014). Carnivorans are oF interest because they are regularly Found living aMong people and even in urban environMents (Gehrt et al. 2010). In general, carnivorans are extremely variable in their behaviors and can be found across the 1Department of Environmental Conservation, University of Massachusetts, Amherst, MA 01003. 2US Geological Survey Massachusetts Cooperative Fish and Wildlife Research Unit, University of Massachusetts, Amherst, MA 01003. 3US Geological Survey, Reston, VA 20192. *Corresponding author - [email protected]. Manuscript Editor: Joseph Johnson 325 2019 Northeastern Naturalist Vol. 26, No. 2 E.G. LeFlore, T.K. Fuller, J.T. Finn, S. DeStefano, and J.F. Organ globe in vastly diFFerent environMents, froM the arid deserts oF AFrica to the frozen tundra of Siberia (Fuller et al. 2010). Carnivorans are thought to be especially vul- nerable to habitat loss and fragmentation because of their need for large amounts of space, low densities, and conficts with humans (Crooks 2002, Noss et al. 1996). However, even as developMent has increased, soMe carnivorans have expanded their ranges (e.g., Canis latrans (Say) [Coyote]; Parker 1995), increased their nuM- bers (e.g., Lynx rufus (Schreber) [Bobcat]; Roberts and CriMMons 2010), and have higher densities in urban than in rural areas (e.g., Procyon lotor (L.) [Raccoon]; Prange et al. 2003). Carnivorans react diFFerently to pressures oF urban environMents, but a Few gen- eralizations can be Made about species that thrive in such regions (Fuller et al. 2010). Urban carnivorans tend to be relatively small to medium in size and usually have higher reproductive capabilities than those found in areas that are less developed. Ad- ditionally, urban carnivorans tend to be dietary generalists, surviving on vegetation, live aniMals, carrion, and huMan reFuse, depending on availability. Finally, urban carnivorans tolerate close proximity to humans. This tolerance is aided by humans who, purposefully or not, provide resources such as food and shelter (e.g., Kanda et al. 2009). Understanding how urbanization, development, and habitat fragmentation aFFect carnivoran coMMunities is integral to successFul conservation in the Face of changing landscapes (NieMelä 1999, Prange and Gehrt 2004). CoMpetition aMong syMpatric carnivorans For available resources in urbanized and fragmented ecosystems can be both direct (aggressive interactions) and indirect (exploitative coMpetition For resources) (Di Bitetti et al. 2009, Linnell and Strand 2000). Resource partitioning (spatially or temporally) enables species in competi- tion to occupy the saMe areas and MiniMize negative interactions (Carothers and Jaksic 1984, Di Bitetti et al. 2009). Larger carnivorans iMpact the distribution, population, and activity of smaller carnivorans through competition and preda- tion (Crooks et al. 2010, PaloMares and Caro 1999, Sargent et al. 1987). In urban systems, competition among carnivorans likely occurs across the gradient of urban- ization (Crooks et al. 2010). In Moderately developed areas, liMited resources and space constrict carnivoran species and cause higher levels of spatial and temporal overlap, resulting in more competition and agonistic interactions among these spe- cies (Crooks et al. 2010). Heavily developed areas where habitat patches are too sMall and isolated May not support larger predators, allowing Mesopredators to thrive, whereas in more natural areas, mesopredators and top predators are able to coexist but mesopredators may use spatiotemporal avoidance to minimize inter- action with top predators (Crooks et al. 2010). Carnivoran community interactions in urban environments are likely to differ between systems and species (Crooks 2002, Crooks et al. 2010, Faeth et al. 2005). This study eMployed autoMatically triggered wildliFe caMeras to investigate the local distribution and possible interactions of 3 canid species: Coyotes, Vulpes vulpes (L.) (Red Fox), and Urocyon cinereoargenteus (Schreber) (Gray Fox). Our aim was to understand the habitat features that infuenced the ways in which these canids used human-infuenced ecosystems while also investigating the impacts each 326 2019 Northeastern Naturalist Vol. 26, No. 2 E.G. LeFlore, T.K. Fuller, J.T. Finn, S. DeStefano, and J.F. Organ canid had on the others. We hypothesized that the local distribution of each focal species would be infuenced not only by landscape characteristics (e.g., land-use type, distance to water, roads or urbanization, elevation, etc.) but also by detection rates of prey and sympatric carnivorans (cf. Johnson et al. 1996). We also hypoth- esized that we would detect Coyotes, Red Foxes, and Gray Foxes Most oFten in areas surrounded by urban developMent (Cove et al. 2012, KapFer and Kirk 2012, Ordeñana et al. 2010). We also compared activity patterns to determine the extent to which temporal partitioning infuenced intraguild dynamics in our study area because temporal avoidance can facilitate spatial coexistence (Carothers and Jaksic 1984, Di Bitetti et al. 2009). Therefore, we posited that there would be temporal partitioning among Coyote, Red Fox, and Gray Fox. Study Area We conducted this study in the Pioneer Valley of western Massachusetts, a section of the Connecticut River Valley encompassing portions of Hampshire (160,327 people; 114 people/km2) and Franklin (71,631 people; 38 people/km2) counties (US Census Bureau 2018). An increased number of carnivoran sightings in higher human-traffc areas led us to develop this study. The 320-km2 study area was bounded to the south by Mt. Holyoke Range State Park, to the north by Mount Toby State Forest, to the west by the Connecticut River, and to the east by Quabbin Reservoir (Fig. 1). This region contained a mixture of land-cover types with more urban, suburban, and agricultural areas in the developed southwestern half of the study area than the more forested northeastern half. The southwestern portion was 53% forested and the northeast portion was 92.7% forested, providing an oppor- tunity for comparison between more and less developed areas. The forested areas within our study area were characterized as transition hardwoods–Pinus strobus (L.) (White Pine) forest (DeGraaf and Yamasaki 2001). Methods Data collection We placed automatic cameras at 79 sites within the study area (Fig. 1) during September–November 2012. We assigned sites to 1 of 3 different land-use classes: forested (F: areas of natural habitat; e.g., forest stands, wetlands, successional habi- tat, etc.), altered (A: green spaces which have been modifed by humans but are not high human-traffc areas; e.g., pastures, croplands, cemeteries, powerlines, etc.), and urban (U: areas with high levels of human use; e.g., residential areas, commer- cial areas, transportation land, junkyards, etc.) (Ordeñana et al. 2010, Riley et al. 2003). We used the “merge” tool in Arc GIS (ESRI 2011) to derive the distribution of these consolidated land-use