Birds on an extinction schedule

~In a comment on a previous post about the grackles, Ianqui mentioned that from a behavioral psychology standpoint it would be interesting to watch the grackles who can no longer get food from the feeders. I don't know if I've talked about it here, but as a matter of fact, I spent some time in a behavioral psych program, and spent my last undergrad year running mice in Skinner boxes. So I know reinforcement schedules and extinction curves and the like. And yes, the grackles have behaved just as Skinner would've predicted. Put on an extinction schedule (no more reinforcement, i.e., food) they try very very hard for a while and then taper off. And then they come back occasionally to try a little and then finally quit responding.

~It's actually pretty funny how much my feeders are like a Skinner box, although I hadn't thought about it until Ianqui mentioned it. For the grackles, landing on the perch is like a bar press in a Skinner box. Before I adjusted the feeders they were on a continuous ratio reinforcement schedule--they always got food. But fixing the feeders meant that landing on the perch produces NO food for them now. So the one grackle who was literally jumping up and down on the perch madly was just like a mouse madly bar pressing trying to get a food pellet in a classic extinction burst. Pretty cool. (And probably more than you ever wanted to know about operant conditioning! But I could so still teach that...)

~But I think I should have fixed the feeders sooner--my other birds really seem to be gone. I've only seen one cardinal in the last few days, and not a single oriole whereas I had 4-5 orioles earlier. I'm afraid that the grackles who are omnivores and not above eating baby birds may have raided some nests and driven the orioles elsewhere. The orioles stuck around all last summer, but the year before that they were only here for a little bit, and I wonder if the same thing happened that year. I will be really sad if they are gone for the summer. I have some finches and chickadees still, but it's awfully quiet out there now, and the feeders are still almost full after a few days which is unusual.