Ecological niche modelling of the wattled crane (Bugeranus carunculatus) suggest range expansion and contraction during the Pleistocene

Abstract

This paper attempts to understand the potential effects of historical climate changes on the distribution of the wattled crane (Bugeranus carunculatus). The potential distribution in past and present climatic scenarios is investigated through ensemble distribution modelling of 232 independent and sparsely distributed occurrence records. Potential effects of climate change were evaluated by means on niche overlap and niche gains and losses across time scales. Massive range expansion was observed from the Last Interglacial (LIG) era to the Last Glacial Maximum (LGM), with loss of suitability in most areas of western Africa and an increase in suitability across southern and eastern Africa. From the LGM, climate suitability tended to establish in southern and eastern Africa with slight disjunction in the mid-Holocene, a trend that was maintained through current distribution. Results indicate the presence of southern and northern refugia, with massive range expansion in central populations. These results support the idea that the current disjunct distribution of the wattled crane is driven by climate oscillations during the Pleistocene that generated range expansion and retraction of the species and also support the hypothesis that the current occurrence of the species is driven by other factors such as food and habitat availability.