Take a hike through any mixed evergreen or pine-oak forest in Northern California and you will most likely be greeted with the very vocal presence of Steller’s jays. These crested jays are some of the noisiest birds in the forests of Northern California.
While Steller’s jays are often seen darting quickly from tree to tree with sharp calls and flashes of blue, they occasionally engage in a more subdued behavior: wing-spreading. I’ve observed this a few times while hiking when a jay suddenly lands on a branch nearby and holds its wings outstretched, motionless, for several seconds while calling.
Wing-spreading is a social display in Steller’s jays
Wing-spreading is a type of social behavior. Often, Steller’s jays will display outstretched wings towards other jays that are encroaching on their territory or are getting too close to active nests.
Twice while hiking, I’ve encountered a Steller’s jay perched on a branch, wings fully outstretched, staring directly at me while calling. This behavior was likely a territorial response. Steller’s jays are known to be protective of their nesting sites, and it’s possible my hiking the nearby trail was seen as a potential threat.
This type of social display is considered low-aggression by ornithologist. This means that the display is non-confrontational. Instead wing-spreading by Steller’s jay is meant to communicate without direct contact that the threat, whether it’s another jay or a person hiking by, needs to move away.
References
Brown, J. L. (1960). An analytical study of aggressive behavior in the Steller’s Jay. University of California, Berkeley.
Brown, J. L. (1963). Aggressiveness, dominance and social organization in the Steller Jay. The Condor, 65(6), 460-484. DOI: 10.2307/1365507
Walker, L. E., P. Pyle, M. A. Patten, E. Greene, W. Davison, and V. R. Muehter (2020). Steller’s Jay(Cyanocitta stelleri), version 1.0. In Birds of the World (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. DOI: /10.2173/bow.stejay.01
