Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Social Bats Pay a Price: Fungal Disease, White-Nose Syndrome ... Extinction?

04.07.2012
Study determines which bat species are headed for trouble

The effect on bat populations of a deadly fungal disease known as white-nose syndrome may depend on how gregarious the bats are during hibernation, scientists have discovered.

Species that hibernate in dense clusters even as their populations get smaller will continue to transmit the disease at a high rate, dooming them to continued decline, according to results of a new study led by biologists at the University of California, Santa Cruz (UCSC).

One gregarious species has surprised biologists, however, by changing its social behavior.

The joint National Science Foundation (NSF) and National Institutes of Health (NIH) Ecology and Evolution of Infectious Diseases (EEID) Program funded the study. The Directorates for Biological Sciences and Geosciences at NSF supports the EEID Program.

"Managing disease outbreaks appears to be a daunting task, given the complexity of most ecosystems," said Sam Scheiner, EEID program director at NSF. "This study, however, shows that in fact we can identify the key factors needed for adequate management."

White-nose syndrome has decimated bat colonies throughout the northeast since it first appeared in New York in 2006. It continues to spread in the United States and Canada.

In the study, researchers analyzed population trends in six bat species in the northeast.

They found that some bat populations are stabilizing at lower abundances, while others appear to be headed for extinction.

The results, published in the current issue of the journal Ecology Letters, centered around data from bat surveys between 1979 and 2010, covering a long period of population growth followed by dramatic declines caused by white-nose syndrome.

"All six species were affected by white-nose syndrome, but we have evidence that populations of some species are beginning to stabilize," said Kate Langwig of UCSC, first author of the paper.

"This study gives us an indication of which species face the highest likelihood of extinction, so we can focus management efforts and resources on protecting those species."

The bats hibernate during the winter in caves and abandoned mines; the number of bats can vary tremendously from one site to another.

The fungus that causes white-nose syndrome grows on the exposed skin of hibernating bats, disrupting their hibernation and causing unusual behavior, loss of fat reserves and death.

Langwig and co-authors looked at how steeply the bat populations at each site declined after they were hit by white-nose syndrome, and whether the severity of the decline was the same in large and small populations.

They found that for species that hibernate alone, the declines were less severe in smaller colonies. For gregarious species, however, even small colonies declined steeply.

"We found that in the highly social species that prefer to hibernate in large, tightly packed groups, the declines were equally severe in colonies that varied from 50 bats to 200,000 bats," said co-author Marm Kilpatrick of UCSC. "That suggests that colonies of those species will continue to decline even when they reach small population sizes."

Trends in the declines of different bat species since the emergence of white-nose syndrome support these predictions.

As populations get smaller, the declines tend to level off for species that roost singly, but not for socially gregarious species.

Surprisingly, however, one highly social species is bucking the trend.

The little brown bat, one of the most common bat species in the northeast, appears to be changing its social behavior, going from a species that preferred to roost in dense clusters to one in which most bats now roost apart from other bats.

"Our analysis suggests that the little brown bats are probably not going to go extinct because they are changing their social behavior in a way that will result in their persisting at smaller populations," Kilpatrick said.

Another gregarious species, the Indiana bat, continues to hibernate mostly in dense clusters and will probably continue to decline toward extinction.

"Since the appearance of white-nose syndrome, both species have become more solitary, but the change is much more dramatic in the little brown bats," Langwig said.

"We now see up to 75 percent of them roosting singly. For Indiana bats, only 8 to 9 percent are roosting alone, which does not appear to be enough to reduce transmission rates."

Even solitary roosting habits may not be enough to save some species, such as the northern long-eared bat.

Although it declined less rapidly as its colonies got smaller, 14 populations of northern long-eared bats became locally extinct within two years after the detection of white-nose syndrome. No populations remained in the study area after five years.

In contrast, populations of tri-colored bats, another solitary species, stabilized at low levels three to four years after disease detection.

"Northern long-eared bats may be particularly susceptible to the disease, so they continue to get hit pretty hard even after transmission rates are reduced," Langwig said.

The two species least affected by white-nose syndrome--big brown bats and eastern small-footed bats--are mostly solitary, although occasionally they roost in small clusters.

It's not clear why they have been less affected by the disease than other species, Langwig said.

According to Kilpatrick, one possibility is that these species roost in sites where conditions are less conducive to the disease.

The study examined the influence of different microclimates within hibernation sites, and found that declines were less severe in drier and cooler sites.

"It appears that the driest and coolest caves may serve as partial refuges from the disease," Kilpatrick said.

In addition to Langwig and Kilpatrick, co-authors of the paper include Winifred Frick of UCSC; Jason Bried of Oklahoma State University; Alan Hicks of the New York State Department of Environmental Conservation; and Thomas Kunz of Boston University.

Much of the bat population data used in the study was collected in surveys conducted by state agencies during the past 40 years.

This research was also funded by Bat Conservation International and the U.S. Fish and Wildlife Service.

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Tim Stephens, UCSC (831) 459-2495 stephens@ucsc.edu
Related Websites
NSF Special Report: Ecology and Evolution of Infectious Diseases: http://www.nsf.gov/news/special_reports/ecoinf/index.jsp

NSF News: Investigating the Spread of Infectious Diseases: http://www.nsf.gov/news/news_summ.jsp?cntn_id=121607

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget is $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives over 50,000 competitive requests for funding, and makes about 11,000 new funding awards. NSF also awards nearly $420 million in professional and service contracts yearly.

Useful NSF Web Sites:
NSF Home Page: http://www.nsf.gov
NSF News: http://www.nsf.gov/news/
For the News Media: http://www.nsf.gov/news/newsroom.jsp
Science and Engineering Statistics: http://www.nsf.gov/statistics/
Awards Searches: http://www.nsf.gov/awardsearch/

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Superconducting vortices quantize ordinary metal

Russian researchers together with their French colleagues discovered that a genuine feature of superconductors -- quantum Abrikosov vortices of supercurrent -- can also exist in an ordinary nonsuperconducting metal put into contact with a superconductor. The observation of these vortices provides direct evidence of induced quantum coherence. The pioneering experimental observation was supported by a first-ever numerical model that describes the induced vortices in finer detail.

These fundamental results, published in the journal Nature Communications, enable a better understanding and description of the processes occurring at the...

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Rapid water formation in diffuse interstellar clouds

25.06.2018 | Physics and Astronomy

Using tree-fall patterns to calculate tornado wind speed

25.06.2018 | Earth Sciences

'Stealth' material hides hot objects from infrared eyes

25.06.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>