Global patterns of fragmentation and connectivity of mammalian carnivore habitat

Abstract

Although mammalian carnivores are vulnerable to habitat fragmentation and require landscape connectivity, their global patterns of fragmentation and connectivity have not been examined. We use recently developed high-resolution habitat suitability models to conduct comparative analyses and to identify global hotspots of fragmentation and connectivity for the world's terrestrial carnivores. Species with less fragmentation (i.e. more interior high-quality habitat) had larger geographical ranges, a greater proportion of habitat within their range, greater habitat connectivity and a lower risk of extinction. Species with higher connectivity (i.e. less habitat isolation) also had a greater proportion of high-quality habitat, but had smaller, not larger, ranges, probably reflecting shorter distances between habitat patches for species with restricted distributions; such species were also more threatened, as would be expected given the negative relationship between range size and extinction risk. Fragmentation and connectivity did not differ among Carnivora families, and body mass was associated with connectivity but not fragmentation. On average, only 54.3 per cent of a species' geographical range comprised high-quality habitat, and more troubling, only 5.2 per cent of the range comprised such habitat within protected areas. Identification of global hotspots of fragmentation and connectivity will help guide strategic priorities for carnivore conservation.

Figure 1.

Global hotspots of fragmentation and core habitat for the world's terrestrial mammalian carnivores (n = 246). Green denotes sites with low fragmentation, where the most carnivore species have the most intact high-quality core habitat. Black denotes sites with high fragmentation, where relatively few carnivore species occur and these species have relatively little core habitat.

Figure 2.

(a) Species richness of the world's terrestrial mammalian carnivores (n = 246) based on the extent of suitable habitat. Blue denotes sites with few carnivore species, and red denotes sites with the highest species richness. (b) Global hotspots of fragmentation and core habitat, standardized by species richness. Green denotes sites with low fragmentation, where carnivores, averaged across species with suitable habitat at a site, have the most intact high-quality core habitat. Black denotes sites with high fragmentation, where carnivore species on average have relatively little core habitat.

Figure 3.

Global hotspots of fragmentation and core habitat for the world's terrestrial mammalian carnivores by family, including (a) Canidae, (b) Felidae, (c) Herpestidae, (d) Hyaenidae, (e) Mephitidae, (f) Mustelidae, (g) Procyonidae, (h) Ursidae and (i) Viverridae. Green denotes sites with low fragmentation, where the most carnivore species have the most intact high-quality core habitat. Black denotes sites with high fragmentation, where relatively few carnivore species occur and these species have relatively little core habitat.

Figure 4.

Global hotspots of habitat connectivity and isolation for the world's terrestrial mammalian carnivores (n = 244). Black denotes sites of low connectivity, with the highest richness of carnivore species that have the least connectivity (most isolation) among high-quality habitat within their current geographical range. Green denotes sites of high connectivity, where relatively few carnivore species have highly isolated high-quality habitat patches.

Figure 5.

Global hotspots of habitat connectivity and isolation for the world's terrestrial mammalian carnivores by Family, including (a) Canidae, (b) Felidae, (c) Herpestidae, (d) Hyaenidae, (e) Mephitidae, (f) Mustelidae, (g) Procyonidae, (h) Ursidae and (i) Viverridae. Black denotes sites of low connectivity, with the highest richness of carnivore species that have the least connectivity (most isolation) among high-quality habitat within their current geographical range. Green denotes sites of high connectivity, where relatively few carnivore species have highly isolated high-quality habitat patches.