Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Why solitary reptiles lay eggs in communal nests

07.09.2009
Reptiles are not known to be the most social of creatures. But when it comes to laying eggs, female reptiles can be remarkably communal, often laying their eggs in the nests of other females. New research in the September issue of The Quarterly Review of Biology suggests that this curiously out-of-character behavior is far more common in reptiles than was previously thought.

Dr. J. Sean Doody (The Australian National University) and colleagues, Drs. Steve Freedberg and J. Scott Keogh, performed an exhaustive review of literature on reptile egg-laying. They found that communal nesting has been reported in 255 lizard species as well as many species of snakes and alligators. The behavior was also documented in 136 amphibian species.

"[O]ur analysis indicates that communal egg-laying is much more common than generally recognized," the authors write.

Despite its prevalence, why reptiles share nests remains a mystery. The phenomenon is easier to explain in birds, many species of which also share nests. Baby birds generally require plenty of parental care after they are born. By nesting together, adult birds can share the burden of feeding and protecting the young—giving a plausible advantage to communal nesting.

Reptiles, on the other hand, generally abandon their eggs before they hatch, so sharing parental duties cannot be the reason reptiles share nests. Many researchers have written off communal nesting in reptiles as a by-product of habitat. In many reptile habitats, good nesting spots are scarce. It is possible, therefore, that females share nests because there is simply nowhere else to nest. As such, communal nesting would have no real evolutionary value on its own; it would be something that simply occurs out of necessity.

But Doody and his colleagues doubt the by-product hypothesis. They cite numerous reports of reptiles nesting communally even when good nesting sites are abundant. Doody believes shared nesting may provide an evolutionary advantage to reptiles after all—despite their lack of parental care.

Building a nest can be hard work for reptiles. Some female lizards, for example, may spend days digging a hole deep enough to deposit eggs. During those days, she is not doing other important things such as finding food. She is also more vulnerable to predators. Females can avoid these costs by simply laying eggs in a nest that someone else has gone to the trouble to build.

But sharing nests can also have a downside. When the eggs hatch, babies are immediately forced to compete with each other for resources. In addition, closely packed egg groups have an increased risk of disease transmission.

Using a mathematical model, Doody and his colleagues show that if the benefits to the mother outweigh the costs to the offspring, communal nesting makes evolutionary sense for reptiles. But when the costs of nesting together outweigh the benefits, we should expect to see solitary nests. This would explain why many reptile species display both solitary and communal nesting strategies.

More study needs to be done to confirm the model, Doody says, but it is a starting point for explaining why communal nesting is so common in otherwise solitary reptiles.

J. Sean Doody, "Communal Egg-laying In Reptiles And Amphibians: Evolutionary Patterns And Hypotheses." The Quarterly Review of Biology 84:3 (September 2009)

The premier review journal in biology since 1926, The Quarterly Review of Biology publishes articles in all areas of biology but with a traditional emphasis on evolution, ecology, and organismal biology.

Kevin Stacey | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Life Sciences:

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

nachricht When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

NASA examines Peru's deadly rainfall

24.03.2017 | Earth Sciences

What does congenital Zika syndrome look like?

24.03.2017 | Health and Medicine

Steep rise of the Bernese Alps

24.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>