Featured Research

from universities, journals, and other organizations

Lights out: Light pollution alters reproduction cycle in lemurs

Date:
July 2, 2014
Source:
Society for Experimental Biology
Summary:
Besides obscuring the stars, light pollution can also disrupt the reproduction of light-sensitive animals. Scientists have shown that light pollution can override the natural reproductive cycle of some animals, making them sexually active out of season.

Anthropogenic light pollution, such as street-lighting, disturbs natural day/night cycles for lemurs.
Credit: Thomas Le Tallec

Besides obscuring the stars, light pollution can also disrupt the reproduction of light-sensitive animals. French scientists have shown that light pollution can override the natural reproductive cycle of some animals, making them sexually active out of season.

"The natural light/dark cycle allows living organisms to time a variety of behavioural and physiological rhythms, including migration, accumulation of reserves, dormancy and reproduction" explains Thomas Le Tallec (PhD Student, Muséum National d'Histoire Naturelle, France), who led the study. "We postulate that chronic exposure to light pollution could impact the human reproductive function as well. Night work and artificial light are associated with menstrual irregularities, decreased fertility, spontaneous abortions and pre-term births. However, this is only a hypothesis and rigorous studies are needed."

Mouse lemurs were chosen for the study as their reproductive cycle is highly sensitive to day length. In winter, male lemurs are sexually inactive and the testes are not visible. In summer, when there is light for more than 12 hours each day, the males become sexually active, with fully functioning gonads. Over five weeks in midwinter, the researchers placed sexually inactive male lemurs inside special climate chambers, where the level of light was controlled by fluorescent lamps. In the control group, the level of light at night was set to only equal that of the full moon. The second group were exposed to yellow LED lights to mimic streetlights. After only two weeks, the light-pollution group had considerably larger testes and higher levels of testosterone than the control group.

These effects are thought to be caused by melatonin, a light-sensitive hormone which regulates mammalian reproduction. Melatonin can only be produced in darkness so that in long-day breeders, such as mouse lemurs, high melatonin levels in winter normally repress sexual activity. When darkness is broken by light pollution, however, melatonin production is inhibited. Consequently, the lemurs subjected to light pollution showed significantly lower concentrations of melatonin. Similar observations have been seen in female mouse lemurs, where light pollution caused sexually-inactive individuals to enter the oestrus cycle. Besides this, light pollution also affected the lemurs' daily activity pattern. As nocturnal animals, lemurs normally become active at night, however light pollution caused this to be delayed and for the animals to be active for much shorter periods.

Anthropogenic light pollution could potentially be mitigated by using directional light sources and low-reflective coatings. Thomas Le Tallec adds that "By reducing air pollution we can reduce the scattering of light in the atmosphere and thus reduce light pollution."

This research was presented at the Society for Experimental Biology Annual Meeting 2014 held at Manchester University, UK, from the 1st - 4th of July.


Story Source:

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


Cite This Page:

Society for Experimental Biology. "Lights out: Light pollution alters reproduction cycle in lemurs." ScienceDaily. ScienceDaily, 2 July 2014. <www.sciencedaily.com/releases/2014/07/140702203804.htm>.
Society for Experimental Biology. (2014, July 2). Lights out: Light pollution alters reproduction cycle in lemurs. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2014/07/140702203804.htm
Society for Experimental Biology. "Lights out: Light pollution alters reproduction cycle in lemurs." ScienceDaily. www.sciencedaily.com/releases/2014/07/140702203804.htm (accessed September 19, 2014).

Share This



More Earth & Climate News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) — An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) — Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
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
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) — A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
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