ABSTRACT
Podogymnura, a Philippine endemic genus of gymnures ("soft-furred hedgehogs"), has been known previously only from the highlands of central Mindanao (P. truei truei and P. t. minima) and from two small islands off the northeast tip of Mindanao (P. aureospinula). Based on a combination of mitochondrial genetic and qualitative and quantitative morphological data, we recognize P. minima, formerly considered a subspecies of P. truei, as a distinct species. We also recognize specimens from two little-studied montane regions of southeastern Mindanao, Mt. Hamiguitan and Mt. Kampalili, as a distinctive new species, P. intermedia n. sp. We estimate that dispersal of a common ancestor from Borneo to Mindanao ca. 1.9 to 3.5 Ma gave rise to Podogymnura, followed by speciation within Mindanao beginning 0.53 to 0.97 Ma. These results further increase the rich diversity of mammals on Mindanao, and underscore the importance of the eastern Mindanao highlands as a likely important but little-studied center of Philippine mammalian diversity.
Subject(s)
Hedgehogs , Animals , PhilippinesABSTRACT
The Philippine archipelago hosts an exceptional diversity of murid rodents that have diversified following several independent colonization events. Here, we report the discovery of a new species of rodent from Mt. Kampalili on eastern Mindanao Island. Molecular and craniodental analyses reveal this species as a member of a Philippine "New Endemic" clade consisting of Tarsomys, Limnomys, and Rattus everetti (tribe Rattini). This new species of "shrew-mouse" is easily distinguished from its relatives in both craniodental and external characteristics including a long, narrow snout; small eyes and ears; short, dark, dense fur dorsally and ventrally; stout body with a tapering, visibly haired tail shorter than head and body length; stout forepaws; bulbous and nearly smooth braincase; narrow, tapering rostrum; short incisive foramina; slender mandible; and narrow, slightly opisthodont incisors. This new genus and species of murid rodent illustrates that murids of the tribe Rattini have exhibited greater species and morphological diversification within the Philippines than previously known and provides evidence that Mt. Kampalili represents a previously unrecognized center of mammalian endemism on Mindanao Island that is deserving of conservation action.
ABSTRACT
Changes in climate and land use can impact natural systems across all levels of ecological organization. Most documented and anticipated effects consider species' properties, including phenologies, geographic distributions, and abundances. Responses of higher-level aggregate community or ecosystem properties have not been considered as they are assumed to be relatively stable due to compensatory dynamics and diversity-stability relationships. However, this assumption may not be as fundamental as previously thought. Here we assess stability in the aggregate properties of total abundance, biomass, and energy consumption for small-mammal communities in the Great Basin, using paired historical and modern survey data spanning nearly a century of environmental change. Results show marked declines in each aggregate property independent of spatial scale, elevation, or habitat type, and a reallocation of available biomass and energy favoring diet and habitat generalists. Because aggregate properties directly reflect resource availability, our findings indicate a regionwide decline in resources of 50% over the past century, which may signal a resource crisis. This work illustrates the power of using aggregate properties as indicators of ecological conditions and environmental change at broad spatial and temporal scales.