Navigation Links
Turtles alter nesting dates due to temperature change says ISU researcher
Date:11/6/2008

AMES, Iowa -- 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.


'/>"/>

Contact: Fred Janzen
fjanzen@iastate.edu
515-294-4230
Iowa State University
Source:Eurekalert

Related biology news :

1. Research shows loggerhead sea turtles threatened by small-scale fishing operations
2. Isotope analysis reveals foraging area dichotomy for Atlantic leatherback turtles
3. Leatherback turtles go with the flow
4. Leatherback turtles newly discovered migration route may be roadmap to salvation
5. UNH researchers tag first-ever free-swimming leatherback turtles in New England
6. Study finds high mortality of endangered loggerhead sea turtles in Baja California
7. Revealing the evolutionary history of threatened sea turtles
8. New study examines how rearing environment can alter navigation
9. Alternative methods proposed to detect pesticides and antibiotics in water and natural food
10. Spaceflight shown to alter ability of bacteria to cause disease
11. Alternative food networks connect ethical producers and consumers and can lead to healthier eating
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/28/2017)... , March 28, 2017 The ... Hardware (Camera, Monitors, Servers, Storage Devices), Software (Video Analytics, ... Region - Global Forecast to 2022", published by MarketsandMarkets, ... 2016 and is projected to reach USD 75.64 Billion ... and 2022. The base year considered for the study ...
(Date:3/24/2017)... 24, 2017 The Controller General of Immigration from ... Abdulla Algeen have received the prestigious international IAIR Award for the ... Continue Reading ... ... Controller Abdulla Algeen (small picture on the right) have received the IAIR ...
(Date:3/23/2017)... The report "Gesture Recognition and Touchless Sensing Market by Technology (Touch-based ... to 2022", published by MarketsandMarkets, the market is expected to be worth USD ... 2022. Continue Reading ... ... ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. ... Cancer Research, London (ICR) and University ... SKY92, SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma ... MUK nine . The University of Leeds ... partly funded by Myeloma UK, and ICR will perform the ...
(Date:10/10/2017)... ... 2017 , ... San Diego-based team building and cooking events company, Lajollacooks4u, has ... The bold new look is part of a transformation to increase awareness, appeal to ... period. , It will also expand its service offering from its signature gourmet cooking ...
(Date:10/10/2017)... 10, 2017 International research firm Parks Associates announced ... at the TMA 2017 Annual Meeting , October 11 in ... residential home security market and how smart safety and security products impact ... Parks Associates: Smart Home ... "The residential security market has ...
(Date:10/9/2017)... DIEGO , Oct. 9, 2017  BioTech ... biological mechanism by which its ProCell stem cell ... critical limb ischemia.  The Company, demonstrated that treatment ... amount of limbs saved as compared to standard ... the molecule HGF resulted in reduction of therapeutic ...
Breaking Biology Technology: