Effects of Forest Fragmentation on Connectivity and Genetic Diversity in an Endemic and an Invasive Rodent in Northwestern Madagascar

• Published in: Genes Vol. 14; no. 7; p. 1451
• Main Authors: Ramsay, Malcolm S, Sgarlata, Gabriele M, Barratt, Christopher D, Salmona, Jordi, Andriatsitohaina, Bertrand, Kiene, Frederik, Manzi, Sophie, Ramilison, Miarisoa L, Rakotondravony, Romule, Chikhi, Lounès, Lehman, Shawn M, Radespiel, Ute
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15-07-2023; MDPI
• Subjects: Analysis; Biodiversity; Biodiversity and Ecology; Biogeography; Biological diversity; Connectivity; Deforestation; Eliurus myoxinus; Environmental Sciences; Forests; Genetic diversity; Genetic research; Habitat fragmentation; Habitats; Inbreeding; Landscape; Nonnative species; Protection and preservation; Rattus rattus; Rodents; Surface water; Madagascar; habitat loss and fragmentation; connectivity; conservation genomics; dispersal; Madagascar; movement; rodents
• ISSN: 2073-4425; 2073-4425
• DOI: 10.3390/genes14071451

Habitat loss and fragmentation are of concern to conservation biologists worldwide. However, not all organisms are affected equally by these processes; thus, it is important to study the effects of living in fragmented habitats on species that differ in lifestyle and habitat requirements. In this study, we examined the dispersal and connectivity patterns of rodents, one endemic (
) and one invasive (
), in two landscapes containing forest fragments and adjacent continuous forest patches in northwestern Madagascar. We generated genetic (RADseq) data for 66
and 81
individuals to evaluate differences in genetic diversity as well as inbreeding and connectivity in two landscapes. We found higher levels of inbreeding and lower levels of genetic diversity in
compared with
. We observed related dyads both within and between habitat patches and positive spatial autocorrelation at lower distance classes for both species, with a stronger pattern of spatial autocorrelation in
. Across each site, we identified contrasting migration rates for each species, but these did not correspond to habitat-matrix dichotomies. The relatively low genetic diversity in the endemic
suggests ecological constraints that require further investigation.