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
New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg
Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News