Q: I have been feeding the wild birds off my deck for several winters and am intrigued by the ways different birds approach and consume seeds.
Chickadees are quite brazen, dashing in practically under the feet of larger birds, picking up one seed and flying off with it to a twig, where they hold the seed by their toes and hammer away at it with their bills to extract the meat. And blue jays act like avian vacuum cleaners, swallowing everything whole so rapidly that they can’t be hulling them.
My question is, are they able to digest the seeds, hulls and all, or do they carry the seeds away and store them somewhere to eat later?
Martha, South Egremont
A: There are many more differences between bird species, than shape and the color of their feathers. And your observations in your recent note attest to that. They are too extensive to mention here, so I will focus on the blue jay, that, common as it is, remains somewhat shrouded in mystery. One would think by now, ornithologists would know everything there is to know about the species. Such is not the case.
I, too, have always thought of blue jays as gluttonous creatures, but it is not gluttony, but more that their feeding habits differ from most other birds visiting our feeders. Blue jays do hold foods like seeds and acorns in their feet while pecking them open, but they also store food in caches to eat at a later date. What may have appeared to you as a jay swallowing seeds whole, is really a jay storing seeds in its gular pouch, an area in the throat and upper esophagus.
It has been noted that a blue jay can carry a total of five acorns at a time to a safe place for storage. Two to three acorns in the pouch, another in the mouth, and one in the tip of the bill. A study on blue jay feeding habits, in which six birds were equipped with radio transmitters, showed each stored (cached) 3,000 to 5,000 acorns in preparation for winter. Imagine how many sunflower seeds a jay can take away at one visit.
We think of the blue jay as a year-round bird, but many thousands migrate south every fall, mostly younger birds. Whether or not they migrate, a few blue jays may be found within their range every winter. Banding records show that some individuals may migrate south one winter and stay put the next, only to migrate again the following year. Just why this happens has not yet been discovered.
I have never seen a blue jay with an acorn, but they apparently favor them, according to Cornell Laboratory of Ornithology, "Their fondness for acorns is credited with helping spread oak trees after the last glacial period." And they are selective about the acorns they cache; they choose and bury acorns that have not been infested with weevils. Smart birds.
Q: I know you have been talking about Robins staying in the Berkshires all winter in your Eagle articles, but I got a surprise today (Jan. 21) when I looked out and saw a flock of robins in my crab apple tree eating the leftovers. Probably about 25 of them. As I walked out to get the Eagle, I saw more robins in the trees all around the neighborhood. I estimate about 100 or more. Encouragement that spring is around the corner.
A: I guess it pays to have home delivery. Unfortunately, your observation is only proof positive that lacking grubs and earthworms, robins rely on fruits. The many crab apple, cherry and dogwood now used extensively in suburban plantings seems to have increased their being seen and reported more regularly. Spring is, indeed, around the corner, we just don’t know how distant that corner is. When I see a robin in April, it will be the harbinger of spring for me -- and I can’t wait.
Questions and comments for Thom Smith: Email Naturewatch@live.com