Featured Research

from universities, journals, and other organizations

To Protect Threatened Bat Species, Street Lights Out

Date:
July 6, 2009
Source:
Cell Press
Summary:
Slow-flying, woodland bats -- which tend to be at greater risk from extinction than their speedier kin -- really don't like street lights, according to a new study. Lesser horseshoe bats will stray from their usual flight routes to steer clear of the artificial glow from lights that are similar to everyday street lights, the new report shows.

Lesser horseshoe bat (Rhinolophus hipposideros). Lesser horseshoe bats will stray from their usual flight routes to steer clear of the artificial glow from lights that are similar to everyday street lights, the new report shows.
Credit: Wikimedia Commons, Public Domain Image

Slow-flying, woodland bats—which tend to be at greater risk from extinction than their speedier kin—really don't like the light, according to a study published online on June 18th in Current Biology, a Cell Press publication. Lesser horseshoe bats will stray from their usual flight routes to steer clear of the artificial glow from lights that are similar to everyday street lights, the new report shows.

The echolocation bats depend on to navigate their way in the dark doesn't help them much when it comes to spotting potential predators, said Gareth Jones of the University of Bristol.

"Bats are not well adapted for detecting predators, and they are vulnerable to attack from birds of prey if they fly in lit conditions," Jones said. "Indeed, predator avoidance is probably the main reason why bats are nocturnal." Slower species, like the lesser horseshoe bat in particular, "are very vulnerable to predators, and emerge in very dark conditions. They seem to be hardwired to avoid light."

In the new study, PhD student Emma Stone installed high-pressure sodium lights that mimicked the intensity and light spectra of street lights along commuting routes of lesser horseshoe bats. The research team found that bat activity in those areas declined dramatically. The bats also delayed their commutes in the presence of lighting, with no evidence for habituation.

While the results did not come as a particular surprise, the researchers were taken aback by the magnitude of the effect.

The researchers suspect that the majority of bats selected alternative routes in response to the disruption of their preferred commute. If those detours led bats to suboptimal terrain in terms of quality or distance to feeding grounds, the animals may suffer significant consequences. For instance, alternate routes may provide reduced shelter, leaving bats, and particularly slower juveniles, at greater risk of predation. They might also leave them more exposed to the elements, such as wind and rain. Longer flight distances would also come with energetic costs.

The findings highlight the importance of adopting species-specific approaches to understanding the consequences of artificial light pollution, the researchers said, noting that some fast-flying bats are actually attracted to lights because of the bugs that swarm them. "Conservation consequences are likely to depend on factors such as predation risk, and will vary according to light type, environmental, and site-specific characteristics," the researchers wrote. "Yet light pollution is rarely considered in habitat management plans and street lighting is excluded from English and Welsh light pollution legislation. This study provides evidence that light pollution may force bats to use suboptimal flight routes and potentially causes isolation of preferred foraging sites, and therefore must be considered when developing conservation policy."

Although questions remain, Stone said she expects that win-win compromises may be possible. "We really need to know what levels of lighting particular bat species can tolerate, and mitigate appropriately," she said. Possible mitigation measures might include turning the lights down at commuting times, directing lights away from flight routes, and constructing alternative flight paths.

The researchers include Emma Louise Stone, Gareth Jones, and Stephen Harris, of the University of Bristol, in Bristol, UK.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "To Protect Threatened Bat Species, Street Lights Out." ScienceDaily. ScienceDaily, 6 July 2009. <www.sciencedaily.com/releases/2009/06/090618124940.htm>.
Cell Press. (2009, July 6). To Protect Threatened Bat Species, Street Lights Out. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2009/06/090618124940.htm
Cell Press. "To Protect Threatened Bat Species, Street Lights Out." ScienceDaily. www.sciencedaily.com/releases/2009/06/090618124940.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins