Predicting the <i>continuum</i> between corridors and barriers to animal movements using Step Selection Functions and Randomized Shortest Paths

Panzacchi, Manuela; Moorter, Bram Van; Strand, Olav; Saerens, Marco; Kivimäki, Ilkka; Clair, Colleen Cassady St.; Herfindal, Ivar; Boitani, Luigi

doi:10.1111/1365-2656.12386

Cited by 117 publications

(183 citation statements)

References 49 publications

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“…These distances surpass average dispersal distances for male grizzly bears recorded in the northern Rocky Mountains (30-42 km), but overlap the range of maximum distances observed (67-176 km; Blanchard and Knight 1991, McLellan and Hovey 2001, Proctor et al 2004. It was only by constraining the starting and end nodes of paths using the RSP approach (Panzacchi et al 2016) that we were able to predict potential paths linking the two populations. Nonetheless, the probability of successful dispersal may still be low, despite recent population expansion.…”

Section: Discussionmentioning

confidence: 48%

“…To avoid conductance values compressing against the boundary of the [0,1] interval, we shifted each x i b value by subtracting the median x i b value for the entire study area (i.e., the median x i b value thus corresponds to a relative probability of 0.5; Panzacchi et al 2016). Conductance values for each cell i were based on the logit À1 (x i b), where x i is the vector of covariate values associated with cell i and b the vector of estimated SSF model coefficients.…”

Section: Randomized Shortest Pathmentioning

confidence: 99%

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Potential paths for male‐mediated gene flow to and from an isolated grizzly bear population

et al. 2017

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For several decades, grizzly bear populations in the Greater Yellowstone Ecosystem (GYE) and the Northern Continental Divide Ecosystem (NCDE) have increased in numbers and range extent. The GYE population remains isolated and although effective population size has increased since the early 1980s, genetic connectivity between these populations remains a long-term management goal. With onlỹ 110 km distance separating current estimates of occupied range for these populations, the potential for gene flow is likely greater now than it has been for many decades. We sought to delineate potential paths that would provide the opportunity for male-mediated gene flow between the two populations. We first developed step-selection functions to generate conductance layers using ecological, physical, and anthropogenic landscape features associated with non-stationary GPS locations of 124 male grizzly bears (199 bear-years). We then used a randomized shortest path (RSP) algorithm to estimate the average number of net passages for all grid cells in the study region, when moving from an origin to a destination node. Given habitat characteristics that were the basis for the conductance layer, movements follow certain grid cell sequences more than others and the resulting RSP values thus provide a measure of movement potential. Repeating this process for 100 pairs of random origin and destination nodes, we identified paths for three levels of random deviation (h) from the least-cost path. We observed broad-scale concordance between model predictions for paths originating in the NCDE and those originating in the GYE for all three levels of movement exploration. Model predictions indicated that male grizzly bear movement between the ecosystems could involve a variety of routes, and verified observations of grizzly bears outside occupied range supported this finding. Where landscape features concentrated paths into corridors (e.g., because of anthropogenic influence), they typically followed neighboring mountain ranges, of which several could serve as pivotal stepping stones. The RSP layers provide detailed, spatially explicit information for land managers and organizations working with land owners to identify and prioritize conservation measures that maintain or enhance the integrity of potential areas conducive to male grizzly bear dispersal.

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Section: Discussionmentioning

confidence: 48%

Section: Randomized Shortest Pathmentioning

confidence: 99%

Potential paths for male‐mediated gene flow to and from an isolated grizzly bear population

et al. 2017

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“…Hence, movement links individual behavior and resource selection (Johnson, Panzacchi et al. , Van Moorter et al. ).…”

Section: Introductionmentioning

confidence: 99%

Temporal variation in resource selection of African elephants follows long‐term variability in resource availability

Tsalyuk

Kilian

Reineking

et al. 2019

Ecological Monographs

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The relationship between resource availability and wildlife movement patterns is pivotal to understanding species behavior and ecology. Movement response to landscape variables occurs at multiple temporal scales, from sub‐diurnal to multiannual. Additionally, individuals may respond to both current and past conditions of resource availability. In this paper, we examine the temporal scale and variation of current and past resource variables that affect movement patterns of African elephants (Loxodonta africana) using sub‐hourly movement data from GPS‐GSM collared elephants in Etosha National Park, Namibia. We created detailed satellite‐based spatiotemporal maps of vegetation biomass, as well as distance from surface water, road and fence. We used step selection functions to measure the relative importance of these landscape variables in determining elephants’ local movement patterns. We also examined how elephants respond to information, in locations they have previously visited, on productivity integrated over different temporal scales: from current to historical conditions. Our results demonstrate that elephants choose patches with higher than average annual productivity and grass biomass, but lower tree biomass. Elephants also prefer to walk close to water, roads, and fences. These preferences vary with time of day and with season, thereby providing insights into diurnal and seasonal behavioral patterns and the ecological importance of the landscape variables examined. We also discovered that elephants respond more strongly to long‐term patterns of productivity than to immediate forage conditions, in familiar locations. Our results illustrate how animals with high cognitive capacity and spatial memory integrate long‐term information on landscape conditions. We illuminate the importance of long‐term high temporal resolution satellite imagery to understanding the relationship between movement patterns and landscape structure.

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“…areas that impede such flow (Panzacchi et al . ), in a context of marked habitat fragmentation (Fahrig ; Hilty, Lidicker & Merenlender, ).…”

Section: Introductionmentioning

confidence: 99%

Combining familiarity and landscape features helps break down the barriers between movements and home ranges in a non‐territorial large herbivore

Marchand

Garel

Bourgoin

et al. 2017

Journal of Animal Ecology

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Recent advances in animal ecology have enabled identification of certain mechanisms that lead to the emergence of territories and home ranges from movements considered as unbounded. Among them, memory and familiarity have been identified as key parameters in cognitive maps driving animal navigation, but have been only recently used in empirical analyses of animal movements. At the same time, the influence of landscape features on movements of numerous species and on space division in territorial animals has been highlighted. Despite their potential as exocentric information in cognitive maps and as boundaries for home ranges, few studies have investigated their role in the design of home ranges of non-territorial species. Using step selection analyses, we assessed the relative contribution of habitat characteristics, familiarity preferences and linear landscape features in movement step selection of 60 GPS-collared Mediterranean mouflon Ovis gmelini musimon × Ovis sp. monitored in southern France. Then, we evaluated the influence of these movement-impeding landscape features on the design of home ranges by testing for a non-random distribution of these behavioural barriers within sections of space differentially used by mouflon. We reveal that familiarity and landscape features are key determinants of movements, relegating to a lower level certain habitat constraints (e.g. food/cover trade-off) that we had previously identified as important for this species. Mouflon generally avoid crossing both anthropogenic (i.e. roads, tracks and hiking trails) and natural landscape features (i.e. ridges, talwegs and forest edges) while moving in the opposite direction, preferentially toward familiar areas. These specific behaviours largely depend on the relative position of each movement step regarding distance to the landscape features or level of familiarity in the surroundings. We also revealed cascading consequences on the design of home ranges in which most landscape features were excluded from cores and relegated to the peripheral areas. These results provide crucial information on landscape connectivity in a context of marked habitat fragmentation. They also call for more research on the role of landscape features in the emergence of home ranges in non-territorial species using recent methodological developments bridging the gap between movements and space use patterns.

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Predicting the continuum between corridors and barriers to animal movements using Step Selection Functions and Randomized Shortest Paths

Cited by 117 publications

References 49 publications

Potential paths for male‐mediated gene flow to and from an isolated grizzly bear population

Potential paths for male‐mediated gene flow to and from an isolated grizzly bear population

Temporal variation in resource selection of African elephants follows long‐term variability in resource availability

Combining familiarity and landscape features helps break down the barriers between movements and home ranges in a non‐territorial large herbivore

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