Jay behavior: an investigation costing meerly peanuts.

[Hill]

I've noticed when feeding Western Scrub Jays whole roasted unsalted peanuts, that initially they are simply opportunists, grabbing a nut and leaving as quickly as possible. Once they get used to a consistant feeding area they slow their pace and seem to fall into one of two separate groups.

The first group I call once-lers . They pick up a peanut, put it down, then try another, and so on, sometimes testing 5-6 or more before deciding which one is the best. They seem to be weighing the nuts comparitively, but may be conducting some other suitability test.

The second group are two-fers. They don't test the nuts the same way. They choose one and then do their best, sometimes taking over a minute, to cram another nut into their beak. Any nut will do as long as it also fits. After feeding this way for a while they often reappear with their mandibles open a small amount, as if the muscles/ligaments have gotten a bit stretched.

I'm curious if Western Scrub Jays in other places behave the same way. There are actually two other Scrub Jays - Island (endemic to Santa Cruz Island) and Florida. Mexican Jays are similar. Jays of the genus Cyanocitta, Blue Jays and Steller's Jays are also good candidates because they are about the same size as Western Scrub Jays. There's even a Eurasian Jay which seems comparible. So this experiment may work in much of North America, and into Europe.

I always feed our local birds when I'm in my yard and then collect any remaining nuts before leaving. Too many crows and squirrels are attracted otherwise. I place the nuts on a low table to allow better observation.

Any Hypographers up for this? It's not rocket science (for that see the lunar X-Prize thread ) and costs only peanuts and minimal time (15-20 minutes at a time).

[Cedars]

Originally Posted by Hill

I've noticed when feeding Western Scrub Jays whole roasted unsalted peanuts, that initially they are simply opportunists, grabbing a nut and leaving as quickly as possible. Once they get used to a consistant feeding area they slow their pace and seem to fall into one of two separate groups.

The first group I call once-lers . They pick up a peanut, put it down, then try another, and so on, sometimes testing 5-6 or more before deciding which one is the best. They seem to be weighing the nuts comparitively, but may be conducting some other suitability test.

The second group are two-fers. They don't test the nuts the same way. They choose one and then do their best, sometimes taking over a minute, to cram another nut into their beak. Any nut will do as long as it also fits. After feeding this way for a while they often reappear with their mandibles open a small amount, as if the muscles/ligaments have gotten a bit stretched.

I'm curious if Western Scrub Jays in other places behave the same way. There are actually two other Scrub Jays - Island (endemic to Santa Cruz Island) and Florida. Mexican Jays are similar. Jays of the genus Cyanocitta, Blue Jays and Steller's Jays are also good candidates because they are about the same size as Western Scrub Jays. There's even a Eurasian Jay which seems comparible. So this experiment may work in much of North America, and into Europe.

The Blue Jays I attract to the dog food I put out for them will show both behaviors here (learned about dog food, Purina Hi-Pro, from Red-headed Woodpeckers who were landing on the dog dish to take food) . What I do not know is which birds are displaying this behavior (cuz who can tell one blue jay from another for the most part) or are they mixing it up dependent on other factors, such as hunger. I havent paid that detailed of attention to see if the two-fer behavior is more common during different conditions, such as during drought, after heavy snow, after bug killing frosts, after the blackberries are done, etc.

I have a few thoughts on this. Younger birds have not learned hording skills or have not encountered food shortages/extreme competition to learn to take as much as possible. You could vary your habits and leave the peanuts out more to see if an increase in food supply changes two-fer behaviors, say next year after the broods are moving around.

Another thing to ponder is territory issues. Your oncers may be within their territory and not feeling the pressure so much as an invader/newbie to the neighborhood.

Another piece to consider is whether seasonally, do you have migrating birds? For example, it was long believed that Blue Jays did not migrate but a lady working on her thesis chose Jays (in nebraska I believe) and tagged birds. She found the Jays in that area migrated and the birds she saw in the summer were different than the birds that she saw in the winter. I dont know if such studies have been done on scrub jays in your area. For this area, the migration may not occur depending on food availability, and other Blue Jays have been observed moving a few hundred miles from their summer areas.

[Hill]

Originally Posted by Cedars

What I do not know is which birds are displaying this behavior (cuz who can tell one blue jay from another for the most part) or are they mixing it up dependent on other factors, such as hunger. I havent paid that detailed of attention to see if the two-fer behavior is more common during different conditions, such as during drought, after heavy snow, after bug killing frosts, after the blackberries are done, etc.

Here in Southern California, between 1000-2000', the seasons are much less variable, and yearly drought, with no rain from May to October, is the norm. (Though a rare last day of summer storm dropped 2" here about a week ago) Though we live in a suburban setting with fairly dense (small yards - our back yard is only 0.05 acres) housing, there is a 1.5 acre undeveloped lot right next door. Chaparral habitat can be found within about 1/8 of a mile and continuous chaparal extending into the Angeles National Forest within 1/4 mile. The behavior is unchanged throughout the year.
We have had one consistant pair of Scrub Jays that lives in an area with many mature trees to our west. They always approach from that direction, and the pair which we call Onceler and Twofer are the original birds in which I noted this behavior. No way to tell for sure which is male or female, and no way to be positive they always play the same roles in collection behavior. But they almost always arrive together and each collects nuts in its own way.

I have a few thoughts on this. Younger birds have not learned hording skills or have not encountered food shortages/extreme competition to learn to take as much as possible. You could vary your habits and leave the peanuts out more to see if an increase in food supply changes two-fer behaviors, say next year after the broods are moving around.

Yes, younger recently fledged birds, just sneak in when they can and leave with whatever they can grab. (Sadly no young produced this year) After a few weeks, they drift away to seek out their own territories.

Sometimes peanuts are out all day. The only observed changes in collection behavior are the hiding of nuts in the yard within sight of the feeding station (though I never have seen a two-fer do this) or just to not come back to the yard that day.

Another thing to ponder is territory issues. Your oncers may be within their territory and not feeling the pressure so much as an invader/newbie to the neighborhood.

Yes. I agree.

Another piece to consider is whether seasonally, do you have migrating birds? For example, it was long believed that Blue Jays did not migrate but a lady working on her thesis chose Jays (in nebraska I believe) and tagged birds. She found the Jays in that area migrated and the birds she saw in the summer were different than the birds that she saw in the winter. I dont know if such studies have been done on scrub jays in your area. For this area, the migration may not occur depending on food availability, and other Blue Jays have been observed moving a few hundred miles from their summer areas.

There is no migration of Scrub Jays here, but there is the occasional arrival of individuals or pairs into the yard. There was quite a "disagreement" in the yard an hour or so ago. A pair arrived from the east. There was much chasing and screaming at each other. The interlopers grabbed the nuts quickly and left.
About a year ago another pair set up a territory to the east and at first behaved in the way of this newer pair. But once they settled in to their territory, they also showed a division in the way they collected peanuts. There was a onceler and a twofer. Still later two more birds, which may or may not have been paired, made for a real circus of yelling and rushing among the six jays. The original two kept up their habits usually since they were stilled dominant. The second pair was a little less consistant. The last two birds always rushed and grabbed, often with a more established bird in persuit.

[Cedars]

Originally Posted by Hill

No way to tell for sure which is male or female, and no way to be positive they always play the same roles in collection behavior. But they almost always arrive together and each collects nuts in its own way.

Yes, younger recently fledged birds, just sneak in when they can and leave with whatever they can grab. (Sadly no young produced this year) After a few weeks, they drift away to seek out their own territories.

Sometimes peanuts are out all day. The only observed changes in collection behavior are the hiding of nuts in the yard within sight of the feeding station (though I never have seen a two-fer do this) or just to not come back to the yard that day.

There is no migration of Scrub Jays here, but there is the occasional arrival of individuals or pairs into the yard. There was quite a "disagreement" in the yard an hour or so ago. A pair arrived from the east. There was much chasing and screaming at each other. The interlopers grabbed the nuts quickly and left.
About a year ago another pair set up a territory to the east and at first behaved in the way of this newer pair. But once they settled in to their territory, they also showed a division in the way they collected peanuts. There was a onceler and a twofer. Still later two more birds, which may or may not have been paired, made for a real circus of yelling and rushing among the six jays. The original two kept up their habits usually since they were stilled dominant. The second pair was a little less consistant. The last two birds always rushed and grabbed, often with a more established bird in persuit.

hmmm.

For some types of birds, the female is the larger of the two. This appears to hold true for Blue Jays around here after watching them plump up with eggs in the spring. I wonder if you staked out an area to the west and observed for an hour or two to try to establish a scrub jay count. You may have Jays waiting for the dominant pair to feast, then a line of lesser birds coming in from that western area. For example, my last trip to Crex Meadows, I came to a spot of a few med growth oaks and they were just covered with Blue Jays. My count was 28 birds as they moved away. Most of them went in a main group of birds, but others flew off in groups of 2 - 5. Crex is a migration staging area, but it did surprise me the large concentration of these birds in that one spot. For the rest of the meadows that day, I saw small groups of 2 or 3 birds (assuming family groups).

Might be worth the effort next spring/summer, if you were able to locate a nest or two and mark some primary feathers on chicks with dots of something... maybe food coloring... I wouldnt want to mess around with cutting feathers on birds not yet in flight. It might help you determine whos doing what in the oncer-twofer aspect.