Tracing the genetics of pigment loss in maternity colonies of Townsend’s big-eared bats, <i>Corynorhinus townsendii</i>

Abstract Hypopigmentation in wildlife is typically rare because pigmentation anomalies likely increase vulnerability to predation, associated pathologies, thermoregulatory challenges, or difficulties in mate selection. In bats, chromatic disorders can affect both fur and skin, yet the frequency of pigmentation anomalies within populations is rarely reported. We present the first records of pigment loss in Townsend’s big-eared bat, Corynorhinus townsendii, in 1 maternity colony (Doris Dee Mine) in eastern California. We tracked pigment loss over time and compared population genetics among C. townsendii maternity colonies across eastern California to determine underlying causes of pigment loss. We found that genetic diversity in Doris Dee was similar to diversity observed in other C. townsendii colonies, indicating that pigment loss was not correlated with genetic diversity in the colony itself or due to low genetic diversity in the sampled populations. Additionally, we found evidence for historic bottlenecks in all maternity colonies in our study area, including Doris Dee. Although individuals with pigment loss were more related to each other than to individuals without pigment loss, we did not find evidence of inbreeding in Doris Dee. These data suggest some degree of heritability of pigment loss, but that the increased incidence of hypopigmentation in Doris Dee is likely not a result of inbreeding or genetic isolation.