Name: Cunha JL

Biodeserts supervisors: Boratyński Z, Campos JC

Title: Habitat variation and its relation to distribution of Saharan rodents

Institution: University of Porto

Status: Completed

Abstract

Habitat and climate are the main factors that influence biodiversity patterns. Sahara, as the largest hot desert and with one of the most arid climate on Earth, has been in constant change over its history. Gerbillus sp, small rodent of the Muridae family that is spread across the entire Sahara represent an interesting model to study effect of environmental changes on organisms’ evolution. In general, animals living in open habitat suffer expose of easy predation due to scarcity of hides. Therefore, strong selection is expected in these organisms. In this study it was tested if there is a linkage between Gerbillus phenotype, namely dorsal fur coloration, and habitat coloration to test for cryptic hypothesis. This was done by analyzing RGB color bands and luminosity using satellite images of the Sahara RGB reflectance and digital photography of the gerbil dorsal fur. With samples gathered from museums and field collected during expeditions to North Africa, information from all over the Sahara was collected and analyzed. Resorting to photography editing software and remote sensing tools it was possible to conduct this study, on a very large geographical scale.

Results showed a high correlation between habitat and animal fur, especially on the red band and luminosity, which supports the camouflage hypothesis as a clear evolutionary mechanism present in the Gerbillus genera. The most likely source of natural selection leading to this phenotypic match with habitat is predation.