Past, present, and future distribution of Afromontane rodents (Muridae: Otomys) reflect climate-change predicted biome changes

Abstract

Climate change constitutes a potential threat to montane biodiversity, particularly in low-altitude, tropical mountains; however, few data exist for the Afromontane taxa. In South Africa, the temperate grassland and fynbos biomes are mostly associated with the Great Escarpment and the high-lying central plateau. Varying contractions of the grassland and fynbos biomes are predicted under different climate scenarios by 2050. Animal taxa adapted to these biomes should suffer similar range declines and can be used to independently test the vegetation models. We constructed MaxEnt models from 271 unique locality records for three species of montane and submontane vlei rats that are closely associated with grassland angoniensis) due to historically documented changes from a grassland-dominated to thicket-dominated landscape.

The conservation status of a poorly known range-restricted mammal, the Nimba otter-shrewMicropotamogale lamottei

“…We selected eight climatic variables to represent average, extreme and seasonal variations in temperature and rainfall, which have previously been used for small mammals in another mountainous region of Africa (Taylor et al 2016). These eight BioClim variables were: Bio 01 (annual mean temperature), Bio 04 (temperature seasonality), Bio 05 (maximum temperature of the warmest month), Bio 06 (minimum temperature of the coldest month), Bio 12 (annual precipitation), Bio 13 (precipitation of the wettest month), Bio 14 (precipitation of the driest month) and Bio 15 (precipitation seasonality).…”

Taxonomic anarchy or an inconvenient truth for conservation? Accelerated species discovery reveals evolutionary patterns and heightened extinction threat in Afro-Malagasy small mammals

“…A revision of the Otomys irroratus species complex resolved two species restricted to the grassland (Otomys auratus) and fynbos (O. irroratus sensu stricto) biomes of South Africa (Taylor et al 2009, Engelbrecht et al 2011). Taylor et al 2009, 2011, Engelbrecht et al 2011, predicted range changes due to climate change under the A2 emission scenario (from Taylor et al 2015Taylor et al , 2016 and changes in the IUCN Red List status with different regional (Friedmann andDaly 2004, Child et al 2016) The two values listed for predicted % range changes refer to values calculated assuming (first value) and not assuming (second value) dispersal. Abbreviations as follow: N/A, not assessed; LC, least concern; DD, data deficient; VU, vulnerable; EN, endangered; CR, critically endangered.…”

“…The habitat of O. auratus Wroughton, 1906 is rather specialized and dependent on undisturbed grasslands and wetlands. The grassland biome is highly threatened and expected to decline considerably under different climate change scenarios, and the range of O. auratus is concomitantly likely to decline by 47-61% by 2050 due to climate change (Taylor et al 2016). Historical data are also available to show that the range of O. auratus has declined in the past 90 years in one important subpopulation in the Soutpansberg Mountains, leading to local extinction.…”

African Mountains in a Changing Climate: Trends, Impacts, and Adaptation Solutions

“…Climate change impacts on mountain biodiversity and ecosystem services Climate change constitutes a potential threat to montane biodiversity (Taylor et al 2015). One of the main effects is the shift in distribution, biomass, and species richness in mountain ecosystems (Hiltner et al 2016;Ponce-Reyes et al 2017).…”

“…This trend is not unique to the Albertine Rift. In South Africa, comparison of historical (from 90 years ago) and current occurrence data from a zone of sympatry in the tropical Soutpansberg Mountains (at 1250 masl) showed complete replacement of the grassland-adapted rodent species (Otomys auratus) by the savanna-adapted species (Otomys angoniensis) because of changes from a grassland-dominated to thicketdominated landscape (Taylor et al 2015).…”