Sunday, March 23, 2008

Crows Stalking Technique


THE BAIT: I've been quite fascinated by the techniques Crows use to stalk food. It doesn't even have to be moving food. They are, of course, also checking for danger. I'm also interested in food preferences. This offering consists of quite a varied menu--eggs, marshmallows, cornbread, and raw bacon.

8:30AM I hear the Crow before I see her. She isn't just cawing she is doing the almost continuous Crow scream from the other side of the stump from where she is currently standing.

I'm guessing she stopped because if you look carefully you will see a Crow wing on the left side of the door frame. At first I just see only two Crows which is unusual. Ordinarily a foraging Crow party consists of three birds.


Crow One who has been placing her foot on the egg before her suddenly turns and seems to be looking at what looks somewhat bird shaped but was last season a black puffball fungus on the trunk. It has since collapsed. She leaves the egg and goes to the left of the stump.

She then circles behind it and doesn't come out the other side.

Crow Two now comes towards the stump.

Crow Two turns and does what looks like the beginning of a false exit. At that moment Crow Three, who has probably been doing sentinel duty up in a tree, comes zooming in from the right, grabs a marshmallow on the fly and continues left. That's one point for the marshmallows.

Then suddenly with a spurt of energy and extremely loud vocalizations, Crow One who's been behind the stump, jump flaps up, and takes a look. I do not think that she grabs anything.
Crow Three, the sentinel is up in the Spruce keeping watch while knoshing on the marsh mellow. Wonder if his beak will get gooed shut?
Rather reminds me of the ancient Scots who would shriek, and run so furiously at their enemies that nine times out of ten their enemy would be so unmanned as to turn tail and run.

Ever wonder where the model for the ancient Harpies came from? Here you are.
Up she comes screaming, feet ready and yet she too doesn't make a grab. Attempting to look for traps? Or to spring them?
Then a dog walker comes by and all three are gone. At least for now. By the next day, the bacon was gone,, all the cornbread disappeared, the eggs were there, and about half the marshmallows. Of course, I don't know who ate what. One of the outdoor cats could have gone for the bacon before the Crows unearthed it. The sparrows could have done in the cornbread, and on.
That's what I get for not having a goodie stump webcam.
Donegal Browne







4 comments:

Terry Davitt Powell said...

I enjoyed this series of pictures and your descriptions of the crows' activities are great. Crows are so smart--it is interesting to try to figure out what they are up to. I read that one of the most favorite foods is cheese. I usually feed them peanuts--which they really like. So, I got some cheese and cut it into squares and put it out with the peanuts and they completely ignored it. then I realized they probably didn't know it was cheese, because the only cheese they know is what they find in dumpsters, melted on pizzas and stuff. so, cut the squares smaller and partly melted it on bread. they figured it out quick! after that, they came in fast for the cheese squares. try it sometime!

Donegal Browne said...

Terry,

Excellent deduction about the cheese. Aren't Crows sensitive to the slightest deviations from the Crow norms of their e
environment? I don't know what it is about cheese but I've never run across and omnivorous bird that didn't go for it though I'd never tried it with Crows, thanks for the tip.

According to the literature on parrots anyway, who also dearly love a nice chunk of properly fermented aged milk, birds are unable to digest lactose. Though there is something in there (or the literature is incorrect and birds digest lactose in a different manner than mammals and therefore it goes unrecognized)that causes them a great urge to go after it.

I read of an example of an outdoor coffee bar where the Crows would avail themselves of the little plastic containers of half and half, complete with peeling the little paper lid off before tiping it up and their beak and--glug, glug.
Quicksilver the African Grey that lives with us, not only asks for cheese but will become quite irate if his portion of macaroni and cheese isn't up to his expectations. He's also been known to help himself to people's glasses of milk.

What is it about birds and dairy?
Another mystery to be investigated.

Karen Anne said...

If they aren't able to digest lactose, does that mean giving them dairy products causes (indelicacy alert) diarrhea, or the other tummy troubles lactose intolerant humans have?

Donegal Browne said...

At least in parrots, they recommend no more than 20% dairy in their diet if you happen to have a bird with an insatiable appetite for dairy. My bird has never had a problem. To tell the truth I'm not sure how they came up with the information that they can't digest lactose. As many birds seem to love cheese I've always wondered if the lactose is digestible but just in a different way from the process used by mammals and we haven't figured it out yet.