Distribution of African savanna elephants (Loxodonta africana), African forest elephants (L. cyclotis), and their hybrids across Africa based on genetic evidence

Abstract

It has recently been recognized that African forest and savanna elephants represent separate species. We analyzed 2445 known-origin elephant samples from across Africa for presence of the two species and hybrids between them, and augmented this with hybrid detection in 4883 samples from ivory seized as contraband. Hybrids were rare overall (6.6 % of reference samples, 1.5 % of contraband samples), occurring only in areas in or near forest-savanna ecotones. Of our known-location hybrids, 117/167 (70 %) were in the Albertine Rift major hybrid zone in eastern DRC and southwestern Uganda, confirming previous reports; in some Albertine sites hybrids outnumbered pure species. Hybrids inferred to be F1 (the product of a forest/savanna mating) were particularly rare, with only 4 found in reference samples and 5 in contraband, suggesting that most hybridization occurred two or more generations ago. We discuss the distribution of the two African elephant species and their hybrids, forces driving hybridization, implications for conservation and management, and areas that need additional sampling effort.