Featured Research

from universities, journals, and other organizations

Lizards Bask In The Sun For A Vitamin D Boost

Date:
April 21, 2009
Source:
University of Chicago Press Journals
Summary:
Keeping warm isn't the only reason lizards and other cold-blooded critters bask in the sun. Chameleons alter their sunbathing behavior based on their need for vitamin D.

Alert juvenile chameleon sunning on a rock. Keeping warm isn't the only reason lizards and other cold-blooded critters bask in the sun.
Credit: iStockphoto

Keeping warm isn't the only reason lizards and other cold-blooded critters bask in the sun. According to a study published in the May/June issue of Physiological and Biochemical Zoology, chameleons alter their sunbathing behavior based on their need for vitamin D.

Related Articles


"It's a longstanding assumption that thermoregulation is the only reason that lizards bask," says Kristopher Karsten, a biologist at Texas Christian University who led the study. "Our results suggest that in addition to thermoregulation, vitamin D regulation appears to have a significant impact on basking behavior as well."

Chameleons, like humans and most other vertebrates, get vitamin D in two ways: They can absorb it from food, and they can produce it in their skin. In order to produce vitamin D, however, the skin must be exposed to UV radiation.

To test whether chameleons alter their sunning behavior based on dietary vitamin D intake, Karsten observed the behavior of two different groups of chameleons. One group had high internal vitamin D levels, thanks to a diet of crickets dusted with a vitamin D powder. The other group ate regular crickets and had low vitamin D. The chameleons were then placed in individual outdoor enclosures that offered open area for direct sun, and a tree to offer filtered sun and shade.

Chameleons generally move from sun to shade throughout the day. But Karsten found that chameleons fed the low vitamin D diet compensated by increasing their exposure to the sun's UV rays. Chameleons with high vitamin D diets, on the other hand, limited their UV exposure.

"It appears that panther chameleons have the ability to gauge their internal vitamin D levels and alter their basking behavior accordingly," Karsten says.

And they do it with remarkable accuracy.

"The chameleons were as effective as mathematically possible by our methods at regulating toward optimal UV exposure for their vitamin D profile," he says. "We thought they were probably pretty good at regulating their UV exposure; we just didn't think they'd be this good."

It's not clear, however, by what mechanism they are able to sense their internal vitamin D levels, but Karsten thinks there may be a brain receptor sensitive to the vitamin.

"Given the ability for panther chameleons to precisely, accurately and effectively adjust basking behavior as a direct result of vitamin D3, [a brain vitamin D receptor] seems likely to occur in panther chameleons."


Story Source:

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


Journal Reference:

  1. Karsten et al. Panther Chameleons, Furcifer pardalis, Behaviorally Regulate Optimal Exposure to UV Depending on Dietary Vitamin D3 Status. Physiological and Biochemical Zoology, 2009; 82 (3): 218 DOI: 10.1086/597525

Cite This Page:

University of Chicago Press Journals. "Lizards Bask In The Sun For A Vitamin D Boost." ScienceDaily. ScienceDaily, 21 April 2009. <www.sciencedaily.com/releases/2009/04/090420182224.htm>.
University of Chicago Press Journals. (2009, April 21). Lizards Bask In The Sun For A Vitamin D Boost. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2009/04/090420182224.htm
University of Chicago Press Journals. "Lizards Bask In The Sun For A Vitamin D Boost." ScienceDaily. www.sciencedaily.com/releases/2009/04/090420182224.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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