The researcher’s methodology was rather unusual: on three occasions over three days, at two different sites, Chouteau investigated the number of attacks that had been made on fake frogs, by counting how many times that had been pecked. Those that were attacked the least looked like local frogs, while those that came from another area had obviously been targeted.
Mathieu Chouteau, Université de Montréal
Research published in the American Naturalist by Université de Montréal's Mathieu Chouteau links the colours and patterns of poison dart frogs to their predators.
The brightly coloured frogs that we find in tropical forests are in fact sending a clear message to predators: “don’t come near me, I’m poisonous!” But why would a single species need multiple patterns when one would do? It appears that when predators do not recognize a poisonous frog as being a member of the local group, it attacks in the hope that it has chanced upon edible prey. “When predators see that their targets are of a different species, they attack. Over the long term, that explains how patterns and colours become uniform in an area,” said Bernard Angers, who directed Chouteau’s doctoral research.
A total of 3,600 life-size plasticine models, each less than one centimetre long, were used in the study. The menagerie was divided between two carefully identified sites in the Amazon forest. “The trickiest part was transporting my models without arousing suspicion at the airport and customs controls,” Chouteau said. He chose plasticine following a review of scientific literature.
“Many scientists have successfully used plasticine to create models of snakes, salamanders and poison dart frogs.” The Peruvian part of the forest proved to be ideal for this study, as two radically different looking groups of frogs are found there: one, living on a plain, has yellow stripes, and the other, living on a mountain, has green patches. The two colonies are ten kilometers apart. 900 fake frogs were placed in each area in carefully targeted positions. Various combinations of colours and patterns were used.
Chouteau was particularly surprised by the “very small spatial scale at which the evolutionary process has taken place.” Ten kilometers of separation sufficed for a clearly different adaptation to take place. “A second surprise was the learning abilities of the predator community, especially the speed at which the learning process takes place when a new and exotic defensive signal is introduced on a massive scale,” Chouteau said.
This process could be at origin of the wide range of colour patterns that are observed not only in frogs but also many species of butterflies, bees, and other animals. Mathieu Chouteau is in fact currently undertaking post-doctoral research into the Heliconius genus of butterfly. “Considering that this kind of project requires regular field work, I have taken up residence in the small town of Tarapoto, where I am responsible for the opening of a research centre that will facilitate the study of neotropical butterfly mimicry,” he said.
• Département de sciences biologiques de l'Université de Montréal : www.bio.umontreal.caMedia contact:
William Raillant-Clark | Newswise Science News
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
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...
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...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
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...
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...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy