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Tolerance and reward equity predict cooperation in ravens (Corvus corax).

Massen JJ, Ritter C, Bugnyar T - Sci Rep (2015)

Bottom Line: The ravens, moreover, also paid attention to the resulting reward distribution and ceased cooperation when being cheated upon.Nevertheless, the ravens did not seem to pay attention to the behavior of their partners while cooperating, and future research should reveal whether this is task specific or a general pattern.Given their natural propensity to cooperate and the results we present here, we consider ravens as an interesting model species to study the evolution of, and the mechanisms underlying cooperation.

View Article: PubMed Central - PubMed

Affiliation: University of Vienna, Department of Cognitive Biology, Vienna, Austria.

ABSTRACT
Cooperative decision rules have so far been shown experimentally mainly in mammal species that have variable and complex social networks. However, these traits should not necessarily be restricted to mammals. Therefore, we tested cooperative problem solving in ravens. We showed that, without training, nine ravens spontaneously cooperated in a loose-string task. Corroborating findings in several species, ravens' cooperative success increased with increasing inter-individual tolerance levels. Importantly, we found this in both a forced dyadic setting, and in a group setting where individuals had an open choice to cooperate with whomever. The ravens, moreover, also paid attention to the resulting reward distribution and ceased cooperation when being cheated upon. Nevertheless, the ravens did not seem to pay attention to the behavior of their partners while cooperating, and future research should reveal whether this is task specific or a general pattern. Given their natural propensity to cooperate and the results we present here, we consider ravens as an interesting model species to study the evolution of, and the mechanisms underlying cooperation.

No MeSH data available.


Experimental set-up.Two birds have to pull the two ends of the string simultaneously to move the feeding platform in reach. If only one bird pulls, the string will just go through the two metal loops anchored to the feeding platform and become unthreaded, while the platform remains stationary. Picture drawn by Nadja Kavcik-Graumann.
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f1: Experimental set-up.Two birds have to pull the two ends of the string simultaneously to move the feeding platform in reach. If only one bird pulls, the string will just go through the two metal loops anchored to the feeding platform and become unthreaded, while the platform remains stationary. Picture drawn by Nadja Kavcik-Graumann.

Mentions: 7 subadult ravens (Corvus corax) living at the Haidlhof research station in Bad Vöslau, Austria, participated in this study (see electronic supplementary materials). We used a loose-string set-up (cf.63); i.e., a feeding platform (78 cm × 10 cm × 1,0 cm) was placed on top of a larger wooden platform (200 cm × 60 cm × 1,5 cm) outside the aviary. The larger platform was at the same level as the inner ground floor of the aviary. The feeding platform was always baited with two pieces of cheese (±5 mm3) 70 cm apart from each other at the front of the platform. Two metal loops were anchored to the feeding platform, and a string was threaded through the metal loops. Both ends of this string then were placed in the aviary, and only if both ends were simultaneously pulled, the feeding platform would move towards the aviary. If only one end of the string would be pulled, the string would become unthreaded and the platform would stay stationary (Fig. 1). The experimenter would then quickly secure and retrieve the string, and end the trial. We choose to secure and retrieve the string because from previous experiences we know that these ravens like to play with strings, and we wanted to avoid that unsuccessful trials were somehow rewarded.


Tolerance and reward equity predict cooperation in ravens (Corvus corax).

Massen JJ, Ritter C, Bugnyar T - Sci Rep (2015)

Experimental set-up.Two birds have to pull the two ends of the string simultaneously to move the feeding platform in reach. If only one bird pulls, the string will just go through the two metal loops anchored to the feeding platform and become unthreaded, while the platform remains stationary. Picture drawn by Nadja Kavcik-Graumann.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595729&req=5

f1: Experimental set-up.Two birds have to pull the two ends of the string simultaneously to move the feeding platform in reach. If only one bird pulls, the string will just go through the two metal loops anchored to the feeding platform and become unthreaded, while the platform remains stationary. Picture drawn by Nadja Kavcik-Graumann.
Mentions: 7 subadult ravens (Corvus corax) living at the Haidlhof research station in Bad Vöslau, Austria, participated in this study (see electronic supplementary materials). We used a loose-string set-up (cf.63); i.e., a feeding platform (78 cm × 10 cm × 1,0 cm) was placed on top of a larger wooden platform (200 cm × 60 cm × 1,5 cm) outside the aviary. The larger platform was at the same level as the inner ground floor of the aviary. The feeding platform was always baited with two pieces of cheese (±5 mm3) 70 cm apart from each other at the front of the platform. Two metal loops were anchored to the feeding platform, and a string was threaded through the metal loops. Both ends of this string then were placed in the aviary, and only if both ends were simultaneously pulled, the feeding platform would move towards the aviary. If only one end of the string would be pulled, the string would become unthreaded and the platform would stay stationary (Fig. 1). The experimenter would then quickly secure and retrieve the string, and end the trial. We choose to secure and retrieve the string because from previous experiences we know that these ravens like to play with strings, and we wanted to avoid that unsuccessful trials were somehow rewarded.

Bottom Line: The ravens, moreover, also paid attention to the resulting reward distribution and ceased cooperation when being cheated upon.Nevertheless, the ravens did not seem to pay attention to the behavior of their partners while cooperating, and future research should reveal whether this is task specific or a general pattern.Given their natural propensity to cooperate and the results we present here, we consider ravens as an interesting model species to study the evolution of, and the mechanisms underlying cooperation.

View Article: PubMed Central - PubMed

Affiliation: University of Vienna, Department of Cognitive Biology, Vienna, Austria.

ABSTRACT
Cooperative decision rules have so far been shown experimentally mainly in mammal species that have variable and complex social networks. However, these traits should not necessarily be restricted to mammals. Therefore, we tested cooperative problem solving in ravens. We showed that, without training, nine ravens spontaneously cooperated in a loose-string task. Corroborating findings in several species, ravens' cooperative success increased with increasing inter-individual tolerance levels. Importantly, we found this in both a forced dyadic setting, and in a group setting where individuals had an open choice to cooperate with whomever. The ravens, moreover, also paid attention to the resulting reward distribution and ceased cooperation when being cheated upon. Nevertheless, the ravens did not seem to pay attention to the behavior of their partners while cooperating, and future research should reveal whether this is task specific or a general pattern. Given their natural propensity to cooperate and the results we present here, we consider ravens as an interesting model species to study the evolution of, and the mechanisms underlying cooperation.

No MeSH data available.