Relating mesocarnivore relative abundance to anthropogenic land‐use with a hierarchical spatial count model

Abstract

There is growing need to develop models of spatial patterns in animal abundance, yet comparatively few examples of such models exist. This is especially true in situations where the abundance of one species may inhibit that of another, such as the intensively‐farmed landscape of the Prairie Pothole Region (PPR) of the central United States, where waterfowl production is largely constrained by mesocarnivore nest predation. We used a hierarchical Bayesian approach to relate the distribution of various land‐cover types to the relative abundances of four mesocarnivores in the PPR: coyote Canis latrans, raccoon Procyon lotor, red fox Vulpes vulpes, and striped skunk Mephitis mephitis. We developed models for each species at multiple spatial resolutions (41.4 km2, 10.4 km2, and 2.6 km2) to address different ecological and management‐related questions. Model results for each species were similar irrespective of resolution. We found that the amount of row‐crop agriculture was nearly ubiquitous in our best models, exhibiting a positive relationship with relative abundance for each species. The amount of native grassland land‐cover was positively associated with coyote and raccoon relative abundance, but generally absent from models for red fox and skunk. Red fox and skunk were positively associated with each other, suggesting potential niche overlap. We found no evidence that coyote abundance limited that of other mesocarnivore species, as might be expected under a hypothesis of mesopredator release. The relationships between relative abundance and land‐cover types were similar across spatial resolutions. Our results indicated that mesocarnivores in the PPR are most likely to occur in portions of the landscape with large amounts of agricultural land‐cover. Further, our results indicated that track‐survey data can be used in a hierarchical framework to gain inferences regarding spatial patterns in animal relative abundance.

Mediterranean Eucalyptus plantations affect small mammal ectoparasites abundance but not individual body condition

“…The assessment of productive systems' impacts on wildlife is commonly based on the evaluation of species richness and/or diversity indexes (e.g., Harich & Treydte, ; Timo, Lyra‐Jorge, Gheler‐Costa, & Verdade, ), which provide information that only allows researchers to have a limited view of the problem, as it is mostly restricted to a presence/absence or individual counts approaches. However, some studies have moved forward in trying to understand the effects of agricultural systems in some taxa and looked how these anthropic systems affect abundance (e.g., Crimmins et al, ; Dotta & Verdade, ; Carrilho, Teixeira, Santos‐Reis, & Rosalino, 2017), or more importantly, occupancy and population density (Cruz, Sarmento, & White, ; Curveira‐Santos, Marques, Björklund, & Santos‐Reis, ; Ramesh & Downs, ) and population structure (e.g., sex‐ratio; Odhiambo, Makundi, Leirs, & Verhagen, ; Bonecker, Portugal, Costa‐Neto, & Gentile, ).…”

Trappings of Success: Predator Removal for Duck Nest Survival in Alberta Parklands

“…Areas where coyotes were reduced might have become attractive refuges for more important hen predators like red fox and weasels [10,55], resulting in increased nesting hen mortality relative to control plots. The dietary breadth of skunks is relatively high [95] and their niche overlaps that of red fox [7], so competitive release resulting from skunk removal also could have benefited weasels and foxes.…”

“…Low nesting success is usually attributed to degradation of breeding habitat, including the loss of nesting cover and wetlands resulting from agricultural, industrial and residential land use [5,6]. Anthropogenic habitat alteration also has led to increased nest predation [4,5,7].…”

“…Anthropogenic resource subsidies, provided unintentionally as food or shelter, is another phenomenon that can benefit generalist predators in highly altered habitats [12,13] like the PPR. Loss of cover, concentration of nests in limited habitat, ease of travel by predators and loss of landscape heterogeneity can enhance foraging efficiency of avian and mammalian predators [7,[14][15][16]. A rich guild of nest predators, arising from anthropogenic changes to the environment, will have a diversity of foraging behaviours that increases the risk to all nests regardless of nest distribution strategy [17,18].…”

Context dependency of top‐down, bottom‐up and density‐dependent influences on cheetah demography

“…Mesopredator population dynamics are frequently attributed to the processes of mesopredator suppression or mesopredator release, in which the density or abundance of an apex predator affects the population size, distribution, or behaviour of the mesopredator (Prugh et al, 2009;Ritchie & Johnson, 2009). However, the effects of apex predators on mesopredator populations remain equivocal in the literature (Crimmins et al, 2016;Gehrt & Prange, 2007). In addition, studies on mesopredator suppression or release often do not consider other mechanisms of population regulation for mesopredators, although research suggests that factors such as environmental productivity or prey availability can modulate mesopredator suppression (Elmhagen & Rushton, 2007;Greenville, Wardle, Tamayo, & Dickman, 2014;Pasanen-Mortensen et al, 2017).…”