Nav: Home

Genetic diversity crucial to Florida scrub-jay's survival

October 14, 2016

Ithaca, NY-Legendary conservationist Aldo Leopold once advised: "To keep every cog and wheel is the first precaution of intelligent tinkering." For the Endangered Florida Scrub-Jay, new research shows that saving every last grouping among its small and scattered remnant populations is vital to preserving genetic diversity--and the long-term survival of the species.  

There are just over 5,000 Florida Scrub-Jays left in the world, with four main populations in central Florida and dozens of smaller satellite populations. The study--published today in the journal Current Biology--shows that these small, peripheral populations are contributing to the overall health of the species, via immigrant birds that move to a new area and offer genetic diversity in mating.

"Conservation efforts are often focused solely on maintaining a few large populations. However, we found that our relatively large study population relies on immigrants from small peripheral populations to maintain genetic diversity," said Nancy Chen, study author and postdoctoral fellow at the University of California, Davis. Chen started the study during her graduate studies and postdoctoral research at Cornell University. "Our results are making us rethink conservation priorities in the future."

Chen and her collaborators, including Cornell Lab of Ornithology director John W. Fitzpatrick, studied the breeding and genetic mixing among a relatively stable population of Florida Scrub-Jays at the Archbold Biological Station in central Florida. Archbold is surrounded by a number of smaller satellite populations a few miles away. Those satellite populations have experienced a 50 percent decline in recent decades, rendering the small remnant groups subject to inbreeding, yet they are still providing a service to their species when one member immigrates to the larger Archbold population.  

The team's analysis shows that on average, immigrant-resident pairs at Archbold share more of their genomes with each other compared to resident-resident Archbold pairs. In other words, offspring with an immigrant for a parent have a more diverse mix of genetic material than offspring of two residents, which are more likely to be inbred.  

The study recorded that as the satellite populations declined from 1995 to 2013, instances of immigration into Archbold fell by about half. As the flow of new birds into the Archbold Florida Scrub-Jay population decreased, inbreeding at Archbold increased, with consequences for the offspring. The study showed higher rates of egg failures, lower nestling weight, and lower first-year survival among offspring whose parents are close relatives. Put simply, inbred Florida Scrub- Jay nestlings were far less likely to survive their first year.  

This study project is one of the few to catalog and analyze the genetics of a single wildlife population through time. The Archbold Florida Scrub-Jay population has been exhaustively genotyped over several decades of research.    

"Our study population of jays at Archbold is one of the largest and best-managed remaining populations of Florida Scrub-Jays," said Chen. "Our result that decreased immigration led to increased inbreeding over time, even at Archbold, emphasizes the importance of beginning active conservation efforts early.  

"It's important to consider preserving small and even inbred populations as well, as they may play a vital role in preserving genetic diversity in larger and seemingly stable populations."  

The Florida Scrub-Jay is the only bird found exclusively in Florida. It was added to the federal Endangered Species List in 1987, with a dwindling population down to less than 10 percent of its pre-settlement numbers. Loss of oak scrub habitat is the primary driver of the continued decline. 
-end-


Cornell University

Related Inbreeding Articles:

International scientists shed new light on demise of two extinct New Zealand songbirds
They may not have been seen for the past 50 and 110 years, but an international study into their extinction has provided answers to how the world lost New Zealand's South Island kokako and huia.
Repairing harmful effects of inbreeding could save the iconic Helmeted Honeyeater
Study combines over 30 years of demanding fieldwork and advanced genetics to quantify how much harm is done by inbreeding in the last wild population of the Helmeted Honeyeater, and identifies ways forward.
Inbreeding depression reduces litter sizes in golden retrievers
Data from the Morris Animal Foundation Golden Retriever Lifetime Study shows that inbreeding depression, the result of breeding closely-related individuals, reduces litter sizes in purebred golden retrievers.
Genomics of Isle Royale wolves reveal impacts of inbreeding
A new paper explores the genetic signatures of a pair of wolves isolated on Isle Royale, a remote national park in Lake Superior.
Surprisingly, inbred isle royale wolves dwindle because of fewer harmful genes
The tiny, isolated gray wolf population on Isle Royale has withered to near-extinction, but not because each animal carries a large number of harmful genes, according to a new genetic analysis.
More Inbreeding News and Inbreeding Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...