Evaluating wildlife translocations using genomics: A bighorn sheep case study

Area of Science:

• Population genetics
• Conservation genomics
• Wildlife restoration

Background:

• Wildlife restoration frequently uses translocations to reintroduce species and bolster small, fragmented populations.
• Understanding the genomic impacts of these efforts is crucial for effective conservation strategies.

Purpose of the Study:

• To examine the genomic consequences of bighorn sheep (Ovis canadensis) translocations and population isolation.
• To inform future bighorn sheep restoration strategies by evaluating the success of past reintroduction and augmentation efforts.

Main Methods:

• Population genomic analysis of 511 bighorn sheep from 17 areas using the Illumina High Density Ovine array.
• Generated datasets of 6,155 to 33,289 single nucleotide polymorphisms (SNPs).
• Conducted clustering, population tree, and kinship analyses to evaluate 24 translocation events.

Main Results:

• Natural gene flow was limited between most bighorn sheep populations, even those with historical connectivity.
• Identified eight successful reintroductions and five successful augmentations based on genetic evidence.
• A single native population founded six reintroduced herds; successful augmentations involved 18-57 animals (males and females), while small groups of two males were undetectable.

Conclusions:

• Genomic distinctiveness between native and reintroduced bighorn sheep herds was observed.
• The study provides insights into the relative success of reintroduction and augmentation efforts and factors influencing them.
• Guidance is offered to enhance the genetic contribution of future translocations for improved bighorn sheep restoration.