Azure-winged Magpies would rather avoid losses than strive for benefits based on reciprocal altruism.

It is no doubt that the reciprocal altruism of humans is unparalleled in the animal world. However, how strong altruistic behavior in the non-human animal is still very controversial. Almost all previous researches allowed only one individual in the dyad for action or dyad to accomplish tasks and obtain rewards simultaneously. Here, we designed current study based on the prisoner's dilemma to investigate reciprocal altruism under interactions of Azure-winged Magpies (Cyanopica cyanus), which is direct reciprocity of allowing subjects obtain rewards, respectively. The results suggest that Azure-winged Magpies failed to show continuously altruistic behavior due to the empiricism that stemmed from interactions, that is, avoiding losses. Meanwhile, the resource exchange game paradigm, which is designed in our study, is worthwhile to study the evolution of cooperation in more species in the future.

Socio-ecological correlates of neophobia in corvids.

Behavioral responses to novelty, including fear and subsequent avoidance of novel stimuli, i.e., neophobia, determine how animals interact with their environment. Neophobia aids in navigating risk and impacts on adaptability and survival. There is variation within and between individuals and species; however, lack of large-scale, comparative studies critically limits investigation of the socio-ecological drivers of neophobia. In this study, we tested responses to novel objects and food (alongside familiar food) versus a baseline (familiar food alone) in 10 corvid species (241 subjects) across 10 labs worldwide. There were species differences in the latency to touch familiar food in the novel object and novel food conditions relative to the baseline. Four of seven socio-ecological factors influenced object neophobia: (1) use of urban habitat (versus not), (2) territorial pair versus family group sociality, (3) large versus small maximum flock size, and (4) moderate versus specialized caching (whereas range, hunting live animals, and genus did not), while only maximum flock size influenced food neophobia. We found that, overall, individuals were temporally and contextually repeatable (i.e., consistent) in their novelty responses in all conditions, indicating neophobia is a stable behavioral trait. With this study, we have established a network of corvid researchers, demonstrating potential for further collaboration to explore the evolution of cognition in corvids and other bird species. These novel findings enable us, for the first time in corvids, to identify the socio-ecological correlates of neophobia and grant insight into specific elements that drive higher neophobic responses in this avian family group. VIDEO ABSTRACT.

Performance of Azure-winged magpies in Aesop's fable paradigm.

In this study, the improved Aesop's fable paradigm-a series of experiments originally used to test whether some animals understand the causality associated with water replacement-was used to explore the cognitive ability of Azure-winged magpies (Cyanopica cyanus). Experimental results on causal cue tasks showed that the Azure-winged magpies prefer water-filled tubes over sand-filled tubes, heavy objects over light objects, and solid objects over hollow objects. However, they failed to notice the diameter and water level of the tubes. They also failed to pass the counterintuitive U-shaped tube task in arbitrary cue tasks. Our results demonstrated that Azure-winged magpies have a certain cognitive ability but not an understanding of causality, a characteristic comparable to that of other corvids. Moreover, Azure-winged magpies exhibited the ability of training transfer and analogical problem solving from the perspective of cognitive psychology. We believe that object-bias has little effect on Azure-winged magpies in this study. We can conclude that the Azure-winged magpies partially completed the tasks by trial-and-error learning.