Global mammal distributions, biodiversity hotspots, and conservation

Area of Science:

• Conservation Biology
• Biodiversity Science
• Zoology

Background:

• Conservation planning often relies on identifying biodiversity "hotspots" to prioritize areas for reserve selection.
• Previous approaches have not fully assessed the congruence of different diversity measures within these hotspots.
• Understanding the overlap between species richness, endemism, and extinction threat is vital for effective conservation strategies.

Purpose of the Study:

• To globally examine distributions of nonmarine mammals to identify patterns of species richness, endemism, and endangerment.
• To evaluate the congruence among hotspots of these three diversity measures in mammals.
• To compare mammalian hotspot congruence with avian patterns to assess the generality of observed diversity patterns.

Main Methods:

• Defined "hotspots" as the richest 2.5% of cells in a global equal-area grid (approximately 1° latitude x 1° longitude).
• Analyzed global distributions of all nonmarine mammal species.
• Compared the spatial overlap of hotspots for species richness, endemism, and extinction threat across mammals and birds.

Main Results:

• Hotspots for species richness, endemism, and extinction threat in mammals were largely noncongruent.
• Only 1% of grid cells and 16% of species were common to all three types of mammalian hotspots.
• Mammalian hotspot noncongruence mirrored patterns found in birds, suggesting a generalizable issue across taxa.

Conclusions:

• Identifying conservation priorities based solely on traditional hotspot definitions is a limited strategy due to poor congruence.
• Conservation planning requires integrated approaches that consider multiple diversity metrics and their spatial distributions.
• Rethinking the central role of hotspots in reserve selection is necessary for more effective global conservation efforts.