Animal behavior, cost-based corridor models, and real corridors

Abstract

Corridors are popular conservation tools because they are thought to allow animals to safely move between habitat fragments, thereby maintaining landscape connectivity. Nonetheless, few studies show that mammals actually use corridors as predicted. Further, the assumptions underlying corridor models are rarely validated with field data. We categorized corridor use as a behavior, to identify animal-defined corridors, using movement data from fishers (Martes pennanti) tracked near Albany, New York, USA. We then used least-cost path analysis and circuit theory to predict fisher corridors and validated the performance of all three corridor models with data from camera traps. Six of eight fishers tracked used corridors to connect the forest patches that constitute their home ranges, however the locations of these corridors were not well predicted by the two cost-based models, which together identified only 5 of the 23 used corridors. Further, camera trap data suggest the cost-based corridor models performed poorly, often detecting fewer fishers and mammals than nearby habitat cores, whereas camera traps within animal-defined corridors recorded more passes made by fishers, carnivores, and all other nontarget mammal groups. Our results suggest that (1) fishers use corridors to connect disjunct habitat fragments, (2) animal movement data can be used to identify corridors at local scales, (3) camera traps are useful tools for testing corridor model predictions, and (4) that corridor models can be improved by incorporating animal behavior data. Given the conservation importance and monetary costs of corridors, improving and validating corridor model predictions is vital.

Terrestrial animal tracking as an eye on life and planet

“…Geofencing also allows automated changes directly to a tag's GPS data collection protocols to adjust sampling frequency at places or times of particular interest, such as initiation of dispersal or migration. Furthermore, live data allow field biologists to immediately backtrack an animal's path and collect additional data, including locating predator kill sites or following snow tracks to identify highway underpass use (15). Live data from tagged animals can also provide a powerful tool to engage public interest, involve citizen scientists, and obtain additional data from the field (e.g., Animal Tracker and Global Shark Tracker smartphone applications).…”

Landscape composition mediates movement and habitat selection in bobcats (Lynx rufus): implications for conservation planning

“…Individual movement choices affect habitat use, dispersal patterns, mating systems, reproductive success and territorial interactions, which in turn can influence population viability (Turchin 1998). Conservation planners have long recognized that corridors have the capacity to facilitate animal movement and population persistence in landscapes that are increasingly threatened by habitat loss and fragmentation (Beier and Noss 1998;Palomeres 2001;LaPoint et al 2013). To achieve these goals, a fundamental understanding of how animals move through their environment is needed (Allen and Singh 2016).…”

“…However, many habitat suitability models often include data pooled from all behavioral states (e.g., moving, resting, foraging) and do not estimate suitability based solely on moving individuals (Klar et al 2008;Chetkiewicz and Boyce 2009). Such practices may obscure the actual suitability of an area for facilitating movement (LaPoint et al 2013).…”

“…For example, LaPoint et al (2013) used GPS technology to identify cost-surface maps for individual fishers (Martes pennanti) based on the individual's habitat preferences when moving from one resting location to another. At a landscape or ecoregional scale, the central challenge is how to scale up from individually collared animals to the population as a whole, with an ultimate goal of defining corridors that connect conserved areas and provide dispersal opportunities between subpopulations.…”

A multi-method approach to delineate and validate migratory corridors

“…The use of resistance surfaces to represent the landscape between migratory endpoints and algorithms to delineate movement pathways has increased over the last decade (Sawyer et al 2009;Poor et al 2012;LaPoint et al 2013;Cushman et al 2013;McClure et al 2016). Beier et al (2008) described many of the steps, choices, and assumptions involved in corridor (or linkage) delineation and 55 design, and Zeller et al (2012) provided guidance for defining the resistance surface(s).…”