Data from: The genetic legacy of 50 years of desert bighorn sheep translocations

Conservation biologists have increasingly used translocations to mitigate
population declines and restore locally extirpated populations. Genetic
data can guide the selection of source populations for translocations and
help evaluate restoration success. Bighorn sheep (Ovis canadensis) are a
managed big game species that suffered widespread population extirpations
across western North America throughout the early 1900’s. Subsequent
translocation programs have successfully re-established many formally
extirpated bighorn herds, but most of these programs pre-date
genetically-informed management practices. The state of Nevada presents a
particularly well-documented case of decline followed by restoration of
extirpated herds. Desert bighorn sheep (O. c. nelsoni) populations
declined to less than 3,000 individuals restricted to remnant herds in the
Mojave Desert and a few locations in the Great Basin Desert. Beginning in
1968, the Nevada Department of Wildlife translocated ~2,000 individuals
from remnant populations to restore previously extirpated areas, possibly
establishing herds with mixed ancestries. Here we examined genetic
diversity and structure among remnant herds and the genetic consequences
of translocation from these herds using a genotyping-by-sequencing
approach to genotype 17,095 loci in 303 desert bighorn sheep. We found a
signal of population genetic structure among remnant Mojave Desert
populations, even across geographically proximate mountain ranges.
Further, we found evidence of a genetically distinct, potential relict
herd from a previously hypothesized Great Basin lineage of desert bighorn
sheep. The genetic structure of source herds was clearly reflected in
translocated populations. In most cases, herds retained genetic evidence
of multiple translocation events and subsequent admixture when founded
from multiple remnant source herds. Our results add to a growing
literature on how population genomic data can be used to guide and monitor
restoration programs.