As mentioned in Adventures in Bird Feeding, we have a basket nailed to the top of our courtyard fence so that we can feed blue jays sunflower seed. Occasionally, we also placed peanuts on the ground for them to eat. This is about a time we changed things a little and dropped the peanuts into the basket.
Blue Jays love sunflower seed. They like them whole. They like them even more if they shelled into just the hearts. They will stand around and stuff their craws with the seed before leaving. While whole sunflower seed is a wonderful fat rich food providing enormous amounts of energy and nutrition, it does have some problems. Jays eat just the hearts. To eat the heart of a whole sunflower seed, they must take one seed, fly to a nearby tree, place it between their toes, and peck at it until it cracks enough for them to harvest the nutritious heart. As large as Jays are, this is apparently the most efficient technique they have to eat whole sunflower seeds. But it is extremely slow.
In case you are unaware, many small and medium sized birds also like whole sunflower seeds. Cardinals, for example, seek them out also. But the process is simpler for a cardinal. A cardinal takes the seed into its mouth and crushes it enough for to extract the heart. In the process, the husks fall out of either side of its mouth. (I would love some really close up photography of exactly how cardinals do all of this.) Unlike jays, Cardinals can easily process and eat a great quantity of seed in a small amount of time. So the seeds are a more more efficient source of food value for them than for jays.
Chickadees love sunflower seed, too. Chickadees (10-11 grams) are tiny birds, are a fraction (1/8th) the weight of a Jay (70-100 grams). They use the same technique of seed between the toes to extract the sunflower heart and they are about as fast at it as well. So relative to their food needs, whole sunflower seeds are an efficient source of food for them also.
It very logical then that blue jays love peanuts even more than they love sunflower seed—especially in the shell. Peanuts are much easier to open and the food value is significantly greater than a sunflower seed. This is especially true when the shell contains two or more peanuts. The shell acts as a container allowing the jay to bring in a really huge haul to the family. I can just imagine all the praise daddy blue jay gets when he brings two nuts in the shell to mom and the nestlings. (I have seen jays actually haul off two peanuts at a time: one used the strategy of two in the beak while another stuffed one in its craw and carried the other in its beak.)
When there is a large source of peanuts in a comfortably safe location, blue jays will shop the array of available nuts before choosing just the right one. They will first pick up one and the drop it when they see another that might be more desirable. They may pick up and drop two or three peanuts before making a final decision. Sometimes they select their third choice, sometimes the second, and sometimes they will return to their first choice. Whatever their criteria, they can tell more about the nut when they pick it up than they can by simply looking at it. The whole process reminds me of women shopping for cantaloupes in the produce department by picking them up and smelling them.
As I mentioned earlier, we had placed a basket for the blue jays to eat sunflower seed so that they wouldn’t bother our other feeders. Anytime we let the seed supply get low, they would sit on the basket, look at us, and make various blue jay noises ranging from screeches to bell tones. In fact, when the supply got low, they actually seemed mad at us. I recall when I first experienced this I wondered, “Where in their natural lives do they learn that making a fuss will get them what they want?” (I got a clue when I saw bird parents feeding fussy juveniles.)
The basket on the top of the fence actually worked so well, that the blue jays became reluctant to enter the court yard to get peanuts from the ground. I’m not sure why. Perhaps they got used to the safety of the high-off-the-ground food source. Or perhaps they had a meeting and decided we might get mad at them if they came in the courtyard. But whatever reason, when we occasionally placed peanuts on the ground within easy sight of the blue jays, they still were reluctant to drop to the ground to get the nuts.
So one day, I gave in and placed three or four peanuts in their sunflower seed basket.
As it happens, most birds do not usually fly in from a distance and land on a food source. Even with the basket high on the fence, they typically either land on a tree nearby or elsewhere on the fence. They check it out. They size up the safety. If another bird is in the basket, they make a determination of whether it will be intimidated by them or not. In the case of other species, smaller birds will usually yield right of way. Within the blue jay family, there is an obvious hierarchy. The more timid blue jays will wait out another and then hop in the basket. The more aggressive will drop down on the timid one who hops out of the way and waits for the other to finish before returning.
Knowing all of this on the day I dropped peanuts into the basket for the first time, I wasn’t expecting anything unusual. The blue jays liked sunflower seed. They liked peanuts more. They liked the basket as a food source better than they liked the ground. So, I figured, it’s just logical they would really love peanuts in the basket.
It wasn’t too long before a blue jay showed up. It landed in the nearby tree, hopped around looking at the courtyard and then dropped to the basket on the fence. It was only within inches of the basket, when it became alarmed, flapped its wings wildly, raised itself four feet over the basket, and then dropped several feet away on the fence. It flew back to the tree and looked down. Then it flew back to the fence several feet away. In a sort of choppy walk, it sidled over to the basket with its neck outstretched and timidly glanced sideways into the basket. It looked like Charlie Chaplin without the cane. After it glanced, it ducked a moment to decide on what it had seen. After doing this several times, it finally decided that the basket was safe and those things in the basket were the familiar food favorites, peanuts. Or so it seemed, because the blue jay hopped up on the basket, chose a peanut and headed back to its nest.
It returned later and confidently went through its usual procedure of simply dropping to the basket knowing that it would see peanuts in the basket. But other blue jays which had not been alerted went through the entire procedure that the first one had of jumping up and then re-inspecting the basket until deciding (usually) that it was safe to land in the basket. (A few decided not to wait around to find out if it was dangerous and simply flew off.)
We thought that it was very funny that the birds showed such a fear reaction to the peanuts and we laughingly labeled this feeding adventure “The Attack of the Killer Peanuts.” We presumed they might not be able to identify the unfamiliar shape at first and probably thought they were snakes or something. We decided our jays just might be a bunch of chickens.
We ran out of peanuts. Several months passed. We just feed sunflower seeds. Things settled in with the jays.
One day during the winter, I thought I would provide the jays with an extra treat. I still didn’t gave peanuts so I put sunflower seed hearts in the basket on top of the regular whole sunflower seeds. As I mentioned, blue jays love sunflower seed hearts. They are rich source of food value and the jays don’t have to go through the effort of shelling them. Once again, I thought this would be an unqualified delight to the Jays. And once again, I was wrong. When they dropped to the basket of hearts sitting in the middle of regular whole sunflower seeds, they went through the same alarm and discovery process they had for the peanuts. Several also flew off without further investigation.
This had me scratching my head in bewilderment. I could imagine that peanuts might look vaguely like something dangerous, but I couldn’t see how the sunflower hearts would.
One more event finally helped me solve the puzzle. After several hours, I decided that since the sunflower hearts had scared the blue jays, I would remove them and go back to just plain sunflower seeds. Blue jays which had already been through the discovery process returned and they treated the absence of sunflower hearts the same way they had treated their appearance: with the alarm and investigate procedure. A day later, I emptied the entire basket and the birds reacted to the empty basket the same way.
Speculation: Link to heading
I was slow, but I finally understood. It didn’t matter what was in the basket. What mattered was whether the basket contents looked the same as the last time the jay had visited the basket. So it wasn’t the contents. It was the change that bothered them. And it didn’t matter what the change was. Whether it was something that had formerly been familiar with or whether it was something totally strange, the birds were not going to take chances and land in the basket without investigation if it didn’t look like it did the last time they were there.
Just as in the case of the phantom feeder, I concluded that the birds carried a map of expectations in their minds. In this case, it was a picture of what they expected the basket to contain. When observation didn’t correspond with that map, they would have treat it as dangerous and re-examine the situation. Once again, I am lead to conclude that the birds must have a prodigious memory for the details of their world.
Also, similar to the conclusion of the phantom feeder, I realized that birds don’t actually see where they are landing until the last moment. The jays didn’t become alarmed until their feet almost touched the basket.