On this side of the fence: Functional responses to linear landscape features shape the home range of large herbivores
Data files
Nov 16, 2021 version files 44.42 MB
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data.csv
44.42 MB
Abstract
1. Understanding the consequences of global change for animal movement is a major issue for conservation and management. In particular, habitat fragmentation generates increased densities of linear landscape features that can impede movements.
2. While the influence of these features on animal movements has been intensively investigated, they may also play a key role at broader spatial scales (e.g. the home range scale) as resources, cover from predators/humans, corridors/barriers, or landmarks. How space use respond to varying densities of linear features has been mostly overlooked in large herbivores, in contrast to studies done on predators. Focusing on large herbivores should provide additional insights to understand how animals solve the trade-off between energy acquisition and mortality risk.
3. Here, we investigated the role of anthropogenic (roads and tracks) and natural (ridges, valley bottoms and forest edges) linear features on home range features in five large herbivores. We analysed an extensive GPS monitoring data base of 696 individuals across nine populations, ranging from mountain areas mostly divided by natural features to lowlands that were highly fragmented by anthropogenic features.
4. Nearly all of the linear features studied were found at the home range periphery, suggesting that large herbivores primarily use them as landmarks to delimit their home range. In contrast, for mountain species, ridges often occurred in the core range, probably related to their functional role in terms of resources and refuge. When the density of linear features was high, they no longer occurred predominantly at the home range periphery, but instead were found across much of the home range. We suggest that, in highly fragmented landscapes, large herbivores are constrained by the costs of memorising the spatial location of key features, and by the requirement for a minimum area to satisfy their vital needs.
5. These patterns were mostly consistent in both males and females and across species, suggesting that linear features have a preponderant influence on how large herbivores perceive and use the landscape.
Usage notes
Columns:
- id: animal ids with month and year
- segment: 19 segments of each individual’s monthly home range, where each segment is defined by the 5% contours of the Kernel density distribution from [0-5%] to [90-95%].
- month: month of the home range calculation (numeric)
- year: year of the home range calculation (numeric)
- id2: animal ids
- sex: "F" for female and "M" for males
- road: density ratio for roads in the segment i
- track: density ratio for tracks in the segment i
- ridge: density ratio for ridges in the segment i
- valleybottom: density ratio for valley bottoms in the segment i
- forestedge_OC: density ratio for forest edges between open and closed habitats in the segment i
- forestedge_treest: density ratio for forest edges between tree stands in the segment i
- road_99: road density in the 99% home range
- track_99: track density in the 99% home range
- ridge_99: ridge density in the 99% home range
- valleybottom_99: valley bottom density in the 99% home range
- forestedge_OC_99: forest edge between open and closed habitats density in the 99% home range
- forestedge_treest_99: forest edge between tree stands density in the 99% home range
- road_LA: road density in the local area (circle centred on the home range centroid with a radius equal to the greatest width of the monthly home range at 95%)
- track_LA: track density in the local area (circle centred on the home range centroid with a radius equal to the greatest width of the monthly home range at 95%)
- ridge_LA: ridge density in the local area (circle centred on the home range centroid with a radius equal to the greatest width of the monthly home range at 95%)
- valleybottom_LA: valley bottom density in the local area (circle centred on the home range centroid with a radius equal to the greatest width of the monthly home range at 95%)
- forestedge_OC_LA: forest edge between open and closed habitats density in the local area (circle centred on the home range centroid with a radius equal to the greatest width of the monthly home range at 95%)
- forestedge_treest_LA: forest edge between tree stands density in the local area (circle centred on the home range centroid with a radius equal to the greatest width of the monthly home range at 95%)
- pop: populations of studied animals (caroux: mouflon population of Caroux-Espinouse, auri: roe deer population of Aurignac, bargy: ibex population of Bargy, bauges_chamois: chamois population of Les Bauges, bauges_mouflon: mouflon population of Les Bauges, bauges_roedeer: roe deer population of Les Bauges, chize: roe deer population of Chizé, LPP: red deer population of La Petite Pierre, TF: roe deer population of Trois Fontaines)