Navigation Links
New model more accurately describes migratory animals' extinction risk
Date:11/16/2011

Athens, Ga. Predicting the risk of extinction is a complicated task, especially for species that migrate between breeding and wintering sites. Researchers at the University of Georgia and Tulane University have developed a mathematical model that may make such predictions more accurate. Their work appears in the early online edition of the Royal Society journal Biology Letters.

"The concern is that for a lot of species, we don't know very much about their wintering grounds," said Richard Hall, assistant research scientist in the UGA Odum School of Ecology. "Here in the U.S. we do a pretty good job of conserving breeding habitat for species of concern, but often we have no idea what kinds of threats are facing their non-breeding areas."

Hall and Tulane University's Caz Taylor developed a new model that builds upon a theory of population dynamics known as metapopulation theory.

"A metapopulation is made up of many sub-populations that live in patchily-distributed sites across a landscape," Hall said.

In its simplest form, metapopulation theory describes the fraction of suitable habitat patches occupied by a species. Individuals from a sub-population emigrate from their original site to colonize previously unoccupied patches of suitable habitat where they either thrive or die out. When the rate of successful colonization exceeds the rate of extinction, the proportion of occupied patches rises and the metapopulation is likely to persist.

The problem with simple metapopulation theory is that it assumes colonization occurs continually and is possible from any adjacent patch. It is therefore not applicable to migratory species that seasonally vacate their breeding sites to move to wintering sites, and vice versa. So while the theory has worked for certain conservation effortssuch as informing decisions about the extent of suitable habitat needed to support endangered species such as the northern spotted owl in the Northwest and Bachman's sparrow in the Southeastit does not fit in all cases.

To adapt the theory for migratory species, Hall and Taylor added more complexity to the model. They divided habitat patches into two categories: those used during breeding season and those used for wintering. In their model, colonization only occurs between breeding and wintering (non-breeding) patches, not between patches of the same type.

"With the migratory model, having an unoccupied breeding patch surrounded by lots of suitable breeding habitat does not necessarily mean that the colonization rate is likely to be high," said Hall. "With migratory animals, the colonists of breeding patches come from non-breeding patches far away."

Piping plovers provide a good example. There are only a limited number of suitable habitat patchesopen, sandy beaches that aren't excessively disturbed by human activityso the number and size of the breeding patches in the north and the wintering patches in the southand the distances between themare well known. Through bird banding and tracking technologies, researchers are beginning to develop an understanding of the migration patterns between breeding and wintering patches. Taylor and Hall's model could be applied to describe these birds' population dynamics.

Hall said that the model highlights the importance of taking into account the colonization and extinction rates at both breeding and non-breeding sites, which is more easily said than done.

"What our model shows is that even if the populations in the breeding areas look healthy, without knowing the state of the non-breeding areas, we could be vastly underestimating the likelihood of extinction," he said.


'/>"/>

Contact: Richard Hall
rjhall@uga.edu
706-542-3971
University of Georgia
Source:Eurekalert

Related biology news :

1. Penn biophysicists create new model for protein-cholesterol interactions in brain and muscle tissue
2. Models of eel cells suggest electrifying possibilities
3. Anti-cancer drug prevents, reverses cardiovascular damage in mouse model of premature aging disorder
4. Swamping bad cells with good in ALS animal models helps sustain breathing
5. Moderate use averts failure of type 2 diabetes drugs in animal model
6. Multiple sclerosis research charges ahead with new mouse model of disease
7. A model to measure soil health in the era of bioenergy
8. New model predicts hot spots for mercury in fish
9. New movement models tested at the Smithsonian in Panama
10. Cytori reports benefit of adipose-derived regenerative cells in spinal disc model
11. Lifecycles of tropical cyclones predicted in global computer model
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/4/2017)...   EyeLock LLC , a leader of iris-based ... Patent and Trademark Office (USPTO) has issued U.S. Patent ... an iris image with a face image acquired in ... 45 th issued patent. "The ... the multi-modal biometric capabilities that have recently come to ...
(Date:3/30/2017)... ANGELES , March 30, 2017  On April ... Hack the Genome hackathon at Microsoft,s ... exciting two-day competition will focus on developing health and ... Hack the Genome is the ... been tremendous. The world,s largest companies in the genomics, ...
(Date:3/30/2017)... 2017 Trends, opportunities and forecast in this ... technology (fingerprint, AFIS, iris recognition, facial recognition, hand geometry, ... end use industry (government and law enforcement, commercial and ... and others), and by region ( North America ... Asia Pacific , and the Rest of the ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... CA (PRWEB) , ... October ... ... (https://www.onramp.bio/ ) has launched Rosalind™, the first-ever genomics analysis platform specifically designed ... bioinformatics complexity. Named in honor of pioneering researcher Rosalind Franklin, who made ...
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit is back for ... June 2018 in San Francisco, CA. The Summit brings together current and former FDA ... board directors and government officials from around the world to address key issues in ...
(Date:10/11/2017)... ... ... Disappearing forests and increased emissions are the main causes of the evolving air ... living in larger cities are affected by air pollution related diseases. , That is ... globally - decided to take action. , “I knew I had to take action ...
(Date:10/10/2017)... Angeles, CA (PRWEB) , ... ... ... Inc., a development-stage cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, ... uses of targeted HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in ...
Breaking Biology Technology: