This week’s bird is the California scrub jay, a delightfully bright blue bird which lives along the Pacific coast from British Columbia in Canada down the west coast to Baja California in Mexico. As one would expect, it prefers to live in scrubby areas, especially pinon-juniper forests, oak woods, and the edges of mixed (coniferous and deciduous) forests. One must also assume it enjoys a nice gin cocktail, what with juniper and all. California scrub jays do not migrate, and forage in pairs or small groups. They eat frogs, lizards, the young of other birds, grains, nuts and berries. They are well-adapted to living with people and will eat fruit and vegetables from gardens. California scrub jays were once considered to be the same as other regional varieties of scrub jay, but they are now recognized as their own species.
Scrub jays are notable for their intelligence, and researching this was a ride. They have a brain-to-body mass ratio that is close to those of chimpanzees and cetaceans, two animals that are second only to humans in this category. They are the only non-primate or non-cetacean that has shown the ability to plan ahead. I read a pretty neat anecdote about this. Scientists let the scrub jays hide mealworms and peanuts in little containers, then took the containers away. Some jays were allowed to return to the food after a small amount of time, some after a longer amount. The jays who had been away from their food for the longer interval went straight for the peanuts, because they knew the worms had gone bad by the time they were available again.
Unlike the acorn woodpeckers we covered some time ago, the scrub jay practices “scatter hoarding.” It doesn’t store food away for lean times in a single location, but in as many as 200 individual stashes throughout its range. This is where things get wild. The jays will cache food for later behind objects or in shadows to obscure them as they work, and if they think or know they are being observed by something else that would like to eat the precious stash, they will sometimes return and “re-cache” the food somewhere else. They will also sometimes cache inedible things like pebbles, to throw off any interlopers. All of this points to the California scrub jay exhibiting “theory of mind,” the ability to “understand that other individuals know, or believe, different things than you might, and that they may have different information than you have. The jays must ‘understand’ in some way that the other birds are not only able to see what they are doing, but could also use that information to steal their hard-earned seeds.” Further, a study showed that birds are more likely to re-cache their stash if they themselves have been guilty of successfully stealing another bird’s food. However, they will only do this if they know for sure they are being observed, and won’t bother to go through the trouble if they know they were unseen while burying their loot. This makes sense, but for contrast, studies show that it is only around age four that humans begin to understand that others may not have the same information that they do, and can be tricked. From this it follows that the California scrub jay is more intelligent than a human toddler, and way smarter than Broccoli the dog, who just knows that food comes from the counter, so if you’re at the counter there must be food.
California scrub jays build sturdy nests of twigs and moss one to two feet across, and three to 30 or so feet off the ground. The nests are primarily built by the female of the pair, with the male standing guard. Four to six eggs are incubated for about 16 days, and the young will leave around 18 days later to forge their own path of being clever jerks to other birds. That’s a wrap on the eerily clever California scrub jay. Have a good weekend, everyone!
Links: https://tinyurl.com/un5z9xzc, https://tinyurl.com/2xf3fy4h, https://tinyurl.com/487mvphs
