Siberian Jays’ Evolution of Survival

Did you know that 35% of Siberian jays are killed by predators during their first winter of life? From an evolutionary perspective, how did Siberian jays learn a wide range of antipredator behaviors to improve their survival? Hawks are a predator of Siberian jays, and they go through three different phases to hunt them. The Hawks first perch on a tree, then scan for prey, and then they attack when there is a good opportunity. Based on the observation, the researcher noticed that the jays were able to make situation-specific calls according to hawk’s three distinct behaviors. A test has been done to further confirm this behavior in the following.

At first, the researchers exposed a crowd of jays at feeders in the wild to a perched hawk model and an attacking hawk model. The result showed that the jays uttered in the attacking hawk models and hawk-mobbing calls were also made in the perched-hawk calls in the presence of the hawk model. Then in the absence of a predator model, the jays made a variety of calls that were situation-unspecific calls. They also did a test to see if these situation-specific calls convey information about hawk behavior by performing a playback experiment. As a result, these responses matched the behavior pattern that was observed in the real predator encounters. In addition, they also did playback to see jays reactions by giving playback of alert calls made for searching hawks. They also flew immediately to the nearest cover and they engaged in an active predator-search behavior. The jays did not respond in playback calls of the attacking model due to the fact that the playback experiment did not allow them to see any attacking hawks. Therefore, it leads them to be more likely to actively search for the hawk. Then in the control of playback experiment, it includes picking and social vocalization of jays uttering while foraging, and it did not cause the jays to respond to anything in that behavior. Rather, the Siberian jays kept foraging on the feeder and doing what they usually do.

This study was important and clearly showed how this species of Siberian jays gave distinct alarm calls when encountering a predator. It also helps us understand how animals communicate in a different manner. In this particular case, the jay’s behavior in giving alarms calls is a form of communication and serves to protect their related group members which improve their survival prospects.

Griesser, M. (2008). Referential Calls Signal Predator Behavior in a Group-Living Bird Species. Current Biology, 18(1), 69–73. https://doi.org/10.1016/j.cub.2007.11.069