No evidence of inbreeding depression in fast declining herds of migratory caribou

• Published in: Journal of Evolutionary Biology
• Main Authors: Gagnon, Marianne, Yannic, Glenn, Perrier, Charles, Côté, Steeve D.
• Other Authors: Natural Sciences and Engineering Research Council of Canada, Ministère des Forêts, de la Faune et des Parcs, Labex
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2019
• Subjects: Ecology, Evolution, Behavior and Systematics; Rivière aux Feuilles; Rivière George
• Online Access: http://dx.doi.org/10.1111/jeb.13533; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fjeb.13533; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jeb.13533; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jeb.13533

Abstract Identifying inbreeding depression early in small and declining populations is essential for management and conservation decisions. Correlations between heterozygosity and fitness ( HFC s) provide a way to identify inbreeding depression without prior knowledge of kinship among individuals. In Northern Quebec and Labrador, the size of two herds of migratory caribou (Rivière‐George, RG and Rivière‐aux‐Feuilles, RAF ) has declined by one to two orders of magnitude in the last three decades. This raises the question of a possible increase in inbreeding depression originating from, and possibly contributing to, the demographic decline in those populations. Here, we tested for the association of genomic inbreeding indices (estimated with 22,073 SNP s) with body mass and survival in 400 caribou sampled in RG and RAF herds between 1996 and 2016. We found no association of individual heterozygosity or inbreeding coefficient with body mass or annual survival. Furthermore, those genomic inbreeding indices remained stable over the period monitored. These results suggest that the rapid and intense demographic decline of the herds did not cause inbreeding depression in those populations. Although we found no evidence for HFC s, if demographic decline continues, it is possible that such inbreeding depression would be triggered.