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:

Two in the pack: No changes for Isle Royale wolves
Researchers from Michigan Technological University have released the annual Winter Study detailing updates on the ecology of Isle Royale National Park.
Greater sage-grouse more mobile than previously suspected
Greater sage-grouse are thought to return to the same breeding ground, or 'lek,' every spring -- but how do populations avoid becoming isolated and inbred?
Stabilizing evolutionary forces keep ants strong
Researchers are finding evidence of natural selection that maintains the status quo among ant populations.
Genetic diversity crucial to Florida scrub-jay's survival
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.
New evidence for California Condors' genetic bottleneck
The researchers behind a new study in The Condor: Ornithological Applications analyzed samples from California Condor museum specimens dating back to the 1820s and found that the historical population was surprisingly diverse, but that a substantial amount of that diversity was lost in the last two centuries.
KU researcher points finger at inaccuracy in most biology textbooks
A who's who of experts on fern biology concludes the 'breeding system of ferns has been inaccurately presented in most biology textbooks at all levels of education.'
Termites: Asexual succession strategy
A study led by the Laboratory Evolutionary Biology and Ecology of the Université libre de Bruxelles shows that the humivorous French Guianan termite Cavitermes tuberosus routinely practice asexual queen succession (parthenogenesis).
Bird DNA shows inbreeding linked to shorter lifespan
Pieces of DNA that predict lifespan are shorter in birds that are inbred -- according to new research from the University of East Anglia.
Inbreeding impacts on mothering ability, red deer study shows
Inbred animals have fewer surviving offspring compared with others, a study of red deer in the wild has found.
Mating without males decreases lifespan
Roundworm species reproducing self-fertilization instead of mating with males have shorter lifespans.

Related Inbreeding Reading:

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

Moving Forward
When the life you've built slips out of your grasp, you're often told it's best to move on. But is that true? Instead of forgetting the past, TED speakers describe how we can move forward with it. Guests include writers Nora McInerny and Suleika Jaouad, and human rights advocate Lindy Lou Isonhood.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...