Distinct Genetic Differences in Black Bears
A recent genomic study on black bears in North Carolina reveals significant genetic disparities between populations in the mountainous and coastal regions. Researchers found that coastal black bears exhibit a higher level of genetic vulnerability compared to their mountain counterparts. These findings could assist wildlife management and law enforcement in maintaining the health of bear populations and their habitats.
The research team collected DNA samples over several years, sequencing the entire genomes of 76 black bears—49 from the Mountain Bear Management Unit (MBMU) and 27 from the Coastal Bear Management Unit (CBMU). The analysis identified three genetic clusters, with two emerging from the MBMU and one from the CBMU. A genetic cluster refers to a group of individuals within a species that share similar genetic traits, which can be important for monitoring population health.
“We found that while mountain bears had two distinct, genetically healthy groups, the coastal bears had reduced genetic diversity and elevated inbreeding despite having a larger estimated population,” said Isabella Livingston, a postdoctoral researcher at North Carolina State University’s College of Veterinary Medicine and lead author of a paper detailing the study.
Impact of Habitat Changes
The researchers also incorporated landscape data to contextualize their findings. They observed that the coastal region has experienced more significant environmental changes compared to the mountainous areas. This has led to a reduction in usable habitat for coastal bears, which may be forced into isolated breeding groups, increasing inbreeding and genetic fragility.
Conversely, bears in the MBMU benefit from greater mobility, allowing them to interact with other populations across the Appalachian Mountains. This roaming behavior could contribute to the genetic diversity observed in this area.
“Bears don’t look at state borders and think, ‘Oh, well, better stop there,’” stated Matthew Breen, professor of genomics at NC State’s College of Veterinary Medicine. This suggests that the genetic variation in western North Carolina may be influenced by the movement of bears from neighboring states, unlike the eastern population, which is limited by proximity to the ocean.
Genomic Tools for Wildlife Management
The genomic dataset also enabled the researchers to develop more precise monitoring tools. They created a panel of single nucleotide polymorphisms (SNPs), which are genetic markers useful for identifying the management unit or group to which a bear belongs.
“Basically, groups of SNPs act as genetic fingerprints that we can use to find out where a bear is from and who it is,” Livingston explained. This tool could assist wildlife managers in maintaining healthy bear populations and could also aid law enforcement in investigating poaching cases.
The researchers anticipate that their genomic data will be beneficial in promoting the welfare of black bears and their ecosystems.
“This work shows that genome-wide data of wildlife populations can reveal population structure, demographic history, and emerging connectivity concerns that may not be apparent from census size or management boundaries alone,” Breen noted. The team looks forward to collaborating with the North Carolina Wildlife Resources Commission and other stakeholders to utilize these findings for conservation efforts.
The study was published in the journal Genes and partly funded by the Pittman–Robertson Federal Aid to Wildlife Restoration Grant. Other contributors from NC State include Allison Dickey, Megan Dillon, Nicholas Gould, Jennifer Strules, Christopher DePerno, Michael Stoskopf, and Kelly Meiklejohn.
Source: NC State University
