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!
Plant escape from waterlogging
17.10.2017 | Christian-Albrechts-Universität zu Kiel
Study suggests oysters offer hot spot for reducing nutrient pollution
17.10.2017 | Virginia Institute of Marine Science
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
It's possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Physics and Astronomy
17.10.2017 | Life Sciences