Data From: Genetic viability of small Plains bison (Bison bison) populations a century after reintroduction

Recovering species are often managed in small numbers, requiring
management strategies that maintain genetic variation for long-term
viability. Here, we evaluate the genetic outcomes of two restored American
bison (Bison bison) populations 15 generations after their reintroduction
as Colorado’s first wildlife reintroduction. After initial reintroduction
in 1914 to Genesee park, the herd was split into two separate populations
in 1938. To determine the genetic viability of the restored populations,
we genotyped 36 individuals from both herds, analyzing 52 microsatellite
markers to asses heterozygosity, allelic richness, inbreeding, and
population structure. Both herds exhibit relatively high observed
heterozygosity (Genesee: 0.775 sd = 0.183; Daniels: 0.781 sd = 0.178),
high allelic richness (Genesee: 5.17 sd = 1.45; Daniels: 4.96 sd = 1.46),
and negative FIS values (Genesee: -0.112 bootstraps = -0.158, -0.065;
Daniels: -0.15, bootstraps = -0.191, -0.108), indicating a lack of
inbreeding. Despite ongoing gene flow, the herds remain genetically
distinct, as supported by pairwise FST (0.0354, bootstraps = 0.024,
0.046), Nei’s D (0.136), and AMOVA results (FST = 0.078, p = 0.001).
STRUCTURE analysis further confirmed that the herds maintain genetic
clustering despite some admixture. These results suggest that Denver
Mountain Parks’ long-term management strategies – promoting controlled
gene flow while preventing inbreeding – have been effective in maintaining
genetic variation. Intentional individual movement between herds and
introductions from external metapopulations have contributed to the
long-term viability of these herds. This study highlights the success of
small, intensively managed bison populations in maintaining genetic health
over many generations and underscores the importance of gene flow
strategies in wildlife restoration.