A first-time look at statewide genetics could uncover isolated, in-breeding flocks
By KELLY BOSTIAN
For the CCOF
Predation, habitat loss, and bad weather all are suspects in the decline of Oklahoma’s wild turkeys, but the Oklahoma Department of Wildlife Conservation is looking inward as well—at turkey DNA.
The state’s first late-start hunting season, with a reduced bag limit, ended May 16 with about 100 DNA samples among the harvest. They will go to the Caesar Kleberg Wildlife Research Institute at Texas A&M University-Kingsville. It’s part of a 4.5-year project to examine statewide turkey genetics.
In coming years the researchers hope to collect even more samples and, preferably, samples from every county in the state, said Michael Barrett, an A&M graduate student working on the Oklahoma study.
“In genetics research the more samples you have the better,” he said. “This is just the first year and we did pretty well, next year we’ll change it up a little and there will be more public awareness.”
Oklahoma joins several states with genetic research. Such efforts have been increasing from mountain region states to Texas to the southeast, Barrett said.
“There is a lot of turkey research going on right now. It’s a hot topic and there will be a lot of information that comes out in the next few years,” he said.
One piece of the puzzle
A sudden population drop statewide, and a decade of stagnation in the southeast, spurred on the research. The U.S. Fish and Wildlife Service and research grants are paying for the research, directed by the Wildlife Department and the Oklahoma Cooperative Fish and Wildlife Research Unit at Oklahoma State University.
Genetics could reveal at least a part of the reason behind recent declines, perhaps a major part in some regions, Barrett said. A closer look at genetics also might reveal some interesting information about the purity of the Rio Grande and the eastern subspecies and where hybrids are located.
While OSU researchers capture and monitor turkeys with GPS collars and survey habitat, nest success, and other factors, the Texas contingent will eye DNA and various alleles.
“What we’ll look at are the populations across the state and how they’re doing on a genetic basis. Are they really diverse or are they not diverse?” he said. “It’s increasingly important to make sure that even when we do have good numbers that there is good genetic diversity as well.”
A concept called “bottlenecking” is common among isolated, endangered, and threatened species. DNA samples can help index a population with an “inbreeding coefficient,” he said. Inbreeding can lead to lower clutch sizes, poor general health, and poor survival rates for poults, he said.
Why diversity is good
Genetic diversity not only increases the odds for reproductive success but prepares a flock to handle extremes in weather or disease outbreaks, he said. That diversity can mean the difference between a flock surviving with a few members that can rebuild, or one wiped out by a disease or weather trends.
Habitat broken up by urban sprawl, infrastructure, or natural barriers can isolate populations and lead to the problem, but sometimes it also appears to happen naturally, he said.
“One of the things we’ll look at is habitat fragmentation,” Barrett said. “One example is it will be interesting to see what the populations are like on either side of (Interstate 35). Is there gene flow there, or are they separated?”
The barriers aren’t always obvious, he said. Turkeys that appear genetically isolated but are only divided by distance and what appears to be continuous ideal turkey habitat are the subject of an east Texas study, he said.
OSU professor Dwayne Elmore said genetics in Oklahoma’s southeast are of high interest.
“Like most of the state, the southeast population crashed about the time of the drought in 2011, ’12, and 2013. Most of the rest of the state bounced back after that but the southeast stayed where it was. … Maybe they hit a genetic wall and there is not enough diversity,” Elmore said. “We don’t know. It’s one hypothesis that comes with a long-term depressed population, and it’s part of the reason for adding the genetic component.”
One possible outcome
When genetic diversity is lacking the cure is not unlike what farmers or ranchers must do to keep livestock herds healthy. They bring in new stock.
In the wild, that means trapping and relocating turkeys, much like what was done during early turkey recovery projects of the 1970s and 1980s, when biologists captured and moved turkeys from region to region and state to state.
A bonus from the research will be greater knowledge of the state’s subspecies and natural hybridization between subspecies that use similar habitats, Elmore said.
“There was a lot of trapping and translocation in the 80s, but there are not necessarily great records on where they captured birds and where they put them. A lot of it was trial and error then and learning as they went. All the states were in that position,” he said.
“Hybridization is less a factor where the population is concerned, but that is one thing I will be very interested to see, the hybridization between the Rio Grande and the eastern and where.”
Kelly Bostian is an independent journalist writing for The Conservation Coalition of Oklahoma Foundation, a 501c3 non-profit dedicated to education and outreach on conservation issues facing Oklahomans. To learn more about what we do and to support Kelly’s work, see the About the CCOF page.