Endemic mammalian genera: are they really unique?
The majority (64%) of the extant 1153 mammalian genera occupy only one zoogeographical region and can in that sense be referred to as endemic to that region. The aim in this study was to find out if endemic genera differ in ecological characteristics, e.g. taxonomy, body size, feeding and substrate use, from genera with a more cosmopolitan distribution, and if endemic genera were distributed along a productivity gradient. Location
The sixteen major zoogeographical regions of the world, including continents, islands and oceans. Methods
We grouped the mammal genera according to their distribution in endemic (one region) and cosmopolitan (4–12 regions), respectively. Further, we divided the eleven major terrestrial regions of the world into continental and island regions and examined the effect of productivity on the number of endemic genera. Results
We found statistically significant differences in order, body mass, feeding habit and substrate utilization between the two mammal groups. The endemic genera was dominated by the order Rodentia and were mainly small-sized, insectivore, frugivore/omnivore or herbivore, semifossorial, terrestrial or arboreal. The small fraction (5%) of genera with the widest distribution (4–12 regions) belonged mainly to the orders Chiroptera, Cetacea and Carnivora and were either small- or large-sized, piscivore/squid-eater or insectivore, aquatic, terrestrial or volant. We found only weak relationships with productivity for both sets of regions with a positive slope for continental regions and a negative one for island regions. As all island regions were more productive than continental regions, endemic genera were most common in intermediately productive regions overall. Main conclusions
We conclude that there are major ecological differences between endemic and cosmopolitan genera of mammals.
Document Type: Research Article
Affiliations: Department of Animal Ecology, Swedish University of Agricultural Sciences, Umeå, Sweden
Publication date: 2002-04-01