Featured Research

from universities, journals, and other organizations

Turtles Alter Nesting Dates Due To Temperature Change

Date:
November 20, 2008
Source:
Iowa State University
Summary:
Researchers say turtles nesting along the Mississippi River and other areas are altering their nesting dates in response to rising temperatures.

A male Southern Painted Turtle (Chrysemys picta dorsalis).
Credit: André Karwath / Courtesy of Wikimedia Commons

Turtles nesting along the Mississippi River and other areas are altering their nesting dates in response to rising temperatures, says a researcher from Iowa State University.

Fred Janzen, a professor in ecology, evolution and organismal biology, has studied turtle nesting habits and also accumulated research going back decades in order to track the habits of the turtles to find out when they make nests and lay eggs.

"The results have been astonishing," says Janzen. "In some cases such as regional populations of red-eared sliders, they are now nesting three weeks earlier than they did in the early 1990s. That is the fastest response to climate change of any species that I know of."

The turtles that changed their nesting habits were not only young turtles that are nesting for the first time, said Janzen, but were also older turtles that were changing their habits. This trait, called plasticity, helps animals alter their behavior in the short term until inherited behavior takes over.

"What we found was that in the late 1980s, painted turtles started nesting in early June, now it is on the order of 10 days or more earlier," said Janzen. "These behaviors are showing how the plasticity of the species is helping them survive, but we are wondering what the limit is to their ability to adapt."

Janzen's research took a broad look at the entire species and not just turtle populations that are on the fringe of where the animals can live. Janzen feels this aspect of the collaborative study gives the results added credibility.

Most studies look at populations on the outer limits of a species' environment, and Janzen and his colleagues set out to study the entire species of the turtle populations.

"I think it's human nature to study populations on the margins and not from the center," he said. "And I'm not saying those studies are wrong. In fact I am very confident they are right. But I wanted us to study the entire species. So we said 'What if we looked at the entire range of a species and not just one population at the extremes.'"

Janzen and his collaborators studied mud turtles, sliders, snapping turtles and painted turtles that live in South Carolina, Nebraska, and along the Mississippi River between Iowa and Illinois.

An aspect of the study that surprised Janzen was the gender of the offspring.

The gender of turtle offspring, as with many reptiles, is typically determined by the temperature of the ground where they lay their eggs.

Janzen predicted that with warming temperature, the phenomenon of temperature-dependent sex determination would cause a disproportionate number of females since warmer conditions produce that gender.

Just the opposite seems to be happening. Male babies are outnumbering the females.

"Warmth produces females, so we thought we'd have more females," said Janzen. "But what we think is happening is, since the air feels warmer, the turtles are nesting earlier. But the ground is still cold, so the cold ground is causing us to get more males."

Janzen thinks that the overabundance of males will stress the species. Combined with the adult females being forced to change nesting habits, the stresses could mean the species is under real pressure to adapt swiftly, a pace not popularly considered to characterize turtles, he said.


Story Source:

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


Cite This Page:

Iowa State University. "Turtles Alter Nesting Dates Due To Temperature Change." ScienceDaily. ScienceDaily, 20 November 2008. <www.sciencedaily.com/releases/2008/11/081106181413.htm>.
Iowa State University. (2008, November 20). Turtles Alter Nesting Dates Due To Temperature Change. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2008/11/081106181413.htm
Iowa State University. "Turtles Alter Nesting Dates Due To Temperature Change." ScienceDaily. www.sciencedaily.com/releases/2008/11/081106181413.htm (accessed July 24, 2014).

Share This




More Plants & Animals News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) — An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) — The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Dogs Appear To Become Jealous Of Owners' Attention

Dogs Appear To Become Jealous Of Owners' Attention

Newsy (July 23, 2014) — A U.C. San Diego researcher says jealousy isn't just a human trait, and dogs aren't the best at sharing the attention of humans with other dogs. Video provided by Newsy
Powered by NewsLook.com
Professor Creates Site Revealing Where People's Cats Live

Professor Creates Site Revealing Where People's Cats Live

Newsy (July 23, 2014) — ​It's called I Know Where Your Cat Lives, and you can keep hitting the "Random Cat" button to find more real cats all over the world. Video provided by Newsy
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