Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lizards change their diet to avoid predators

04.12.2009
A scientist from the University of Salamanca and another from Yale University have shown that the presence of predators affects the behaviour of Acanthodactylus beershebensis, a lizard species from the Negev Desert in the Near East. According to the study, these reptiles move less and catch less mobile and different prey if they are under pressure from predators.

Many theoretical models had predicted this result, but until now there had been very few experimental trials and none in the case of saurians (reptiles). This experiment by Dror Hawlena, a researcher at Yale University in the United States, and Valentín Pérez-Mellado, a researcher at the University of Salamanca, has shown that certain animals, such as the insectivore lizard Acanthodactylus beershebensis, can change their behaviour and diet to avoid being eaten.

"When there is greater pressure from predators, the individuals tend to move less and catch more mobile prey from somewhat different groups. The lizards' diet and food-seeking behaviour changed significantly when we experimentally increased the predation pressure on them", Pérez-Mellado tells SINC.

The study, published recently in the journal Oecologia, shows that reptiles threatened by predators become less selective and eat a more diverse range of foods, according to Pérez-Mellado, who was in charge of analysing their diet in Spain. The field work done over the summer months in 2000 and 2001 in the Negev Desert in Israel was carried out by Hawlena.

The scientists studied the species' diet data (trophic ecology) in two different situations – with and without predators. The Spanish researcher analysed the contents of 327 faecal pellets taken from 291 different lizards in order to reconstruct their diet. Ants were the prey most commonly consumed by the lizards, both by those at risk (69.32%) and the controls (67.12%), followed by insects such as termites (19.14% and 19.17% respectively). The difference could be clearly seen in the consumption of seeds, because the lizards hardly consumed these (0.52%) when they were under threat from predators.

An ingenious experiment in the desert

In order to reach these conclusions, Hawlena, who is from the University of the Negev in Israel, designed an experiment that made it possible to prove that the presence of predators affects the behaviour and ecology of this endemic species. "A series of artificial perches were placed in a desert site, which made it easier for shrikes (small birds of prey that catch lizards) to make use of the area, since they could detect the lizards from raised perches such as trees and bushes. These perches were not placed in a similar site nearby, which was used as the control site", explains Pérez-Mellado.

References:

Hawlena, Dror; Pérez-Mellado, Valentín. "Change your diet or die: predator-induced shifts in insectivorous lizard feeding ecology" Oecologia 161(2): 411-419 agosto de 2009.

SINC | EurekAlert!
Further information:
http://www.plataformasinc.es

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>