The ability to recognize our offspring and provide preferential care to our own young is nothing unusual for us. This is much more difficult for the poison frog Allobates femoralis, a highly polygamous species that produces rather indistinguishable tadpoles. According to a study conducted by the Messerli Research Institute of Vetmeduni Vienna, male and female frogs have different strategies for offspring discrimination. Females remember the exact location where they laid their eggs and exhibit preferential behaviour toward their own clutches. Males, on the other hand, assume that all offspring in their territory are their own. The study was published in the journal Animal Behaviour.
The brilliant-thighed poison frog Allobates femoralis is a ground-dwelling species inhabiting the tropical forests of South America. Males guard large territories in which females lay their eggs on fallen leaves. After three weeks of development, the tadpoles are generally transported on the backs of the males to the nearest body of water.
“Females only do so when the male is not in his territory at this time,” explains Eva Ringler from the Department of Comparative Cognitive Research at the Messerli Research Institute of Vetmeduni Vienna.
Own offspring should come first
Tadpole transport has its risks. The tadpoles will only survive if they are transported to a body of water at the right time. During transport, males leave their territory unguarded and risk territorial loss to rivals. Females, on the other hand, must discriminate their own clutch from a number of unrelated clutches. And on the way to the water, predators abound.
“Transport therefore only makes sense when the risk that is taken serves the survival of one’s offspring,” says Ringler. This assumes, however, that A. femoralis can identify its own offspring. “Especially interesting was whether there is a difference between male and female behaviour,” Ringler says.
Males play it safe
In a series of three terrarium trials, the researchers observed whether the frogs would transport only their own or also unrelated tadpoles. In the first test, males and females were presented only with an unrelated clutch. In the second test, an unrelated clutch was added to the terrarium of an individual that already had its own clutch. In the third test, the researchers exchanged the positions of the frog’s own clutch and a foreign clutch to see whether frogs recognize the clutch itself or remember the location of oviposition.
The tests showed that a majority of male frogs transported both their own as well as foreign clutches. They simply let all tadpoles present wiggle onto their back. The parental strategy of males apparently follows the rule of “my territory, my tadpoles”. Males therefore seem to forego the challenge of differentiation entirely.
Females remember the position of their clutch
The female strategy is quite different. They do not transport unrelated tadpoles. The females did not transport foreign tadpoles when they knew the position of their own clutch. But if the researchers switched the position of the female’s own clutch with another one, they only transported the unrelated clutch. This shows that, even weeks later, females remember the exact position where they laid their eggs. When they take over the tadpole transport, they choose the correct clutch based on its location.
Simple rule vs. inner GPS
The behaviour of the frogs in the study also indicated different cost/benefit calculations. Males, owing to their territorial behaviour, follow a simply rule. They assume that all clutches in their territory are theirs. Males therefore have a low risk of neglecting their own offspring. Their behaviour even offers unrelated tadpoles an increased chance of survival.
Females have a much higher risk of transporting a foreign clutch and neglecting their own. In their desire to transport only their own clutch, the female frogs rely on their inner GPS. “Further research is needed to clarify just how the females remember the exact location of oviposition in the dense rain forest,” Eva Ringler concludes.
The article “Sex-specific offspring discrimination reflects respective risks and costs of misdirected care in a poison frog” by Eva Ringler, Andrius Pašukonis, Max Ringler and Ludwig Huber was published in the journal Animal Behaviour. doi:10.1016/j.anbehav.2016.02.008
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Messerli Research Institute (Unit of Comparative Cognition)
University of Veterinary Medicine, Vienna (Vetmeduni Vienna)
T +43 650 9780208
Science Communication / Corporate Communications
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1165
Mag.rer.nat Georg Mair | idw - Informationsdienst Wissenschaft
Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
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...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering