I am always amazed by how well this bird cooperates within the group. They never fight with one another over food. One bird will be perched high up in a tree keeping an eye out for danger while the others work. The sentinel never peaks down to see what they are missing out on. Their head is high up in the air looking for danger.
And like some unspoken understanding, it will leave it’s post and another will instantly take it’s place. If danger approaches they will let out an alarm call. The frequency and urgency of the alarm is in direct relation to how dangerous the sentinel feels the threat is. This has to do with what sort of animal is approaching and the distance of said animal. If a human is walking nearby there will not be any alarm calls. But if that human has a dog with them there most certainly will be.
This behavior is reflected in their offspring rearing as well. The older siblings take part in caring for the youngest birds just like they were the parent. They bring back food and directly feed the fledglings.
Florida Scrub Jays do not cooperate with other groups of Scrub Jays outside of their area. In fact, when they see a bird from another group enter their arena, they let off alarm calls like the world is coming to an end. But, if one group hears danger calls from a distant group, they take advantage of the forewarning and pay more attention to the environment.
Other animals in the area also rely on the Scrub Jay’s warning system. I have seen birds of other species and wild rabbits dive into the bushes when they hear a panicked Scrub Jay alarm.