Sunday, April 17, 2016

Instinctive specialized learning (in Phoebes and other critters)

We are watching a Phoebe rebuilding last year's nest on our Observatory (in a nice safe place by the way, another instinct). This rebuilding may well require different materials than building a nest from scratch, but the amazing thing we saw was where the bird went to get these materials.

We are on a small rise, facing a field where the horses graze. Beyond the field, directly in front of us, grows a row of dense bushes. The same is true for the field border to our right, which is at 90 degrees to the far border. Both borders are well over a hundred yards away, a considerable distance indeed.

First the Phoebe made two successive trips to the bushes across from us, bringing back materials each time. It went to roughly the same place and may well have gone to exactly the same place. Then it abruptly changed behavior and went to the bushes on our right, far away from where it had gone before, again returning with materials. Moreover, on each trip the bird spent only about 10 to 20 seconds finding and collecting the material.

Clearly this bird knew what it wanted and where to get it, despite it being (1) a long way away and (2) in two very different places. The bird must have had detailed advanced knowledge in order to do this. It must have spent some time, perhaps a lot of time, surveying the surrounding area and locating suitable materials, before beginning this round of nest building.

This pre-knowledge behavior implies an instinct to learn. Perhaps something of the form "go forth and locate nest building materials."

And of course the bird must remember what it has learned. I recall noting this long distance behavior last year. Perhaps the bird located the suitable materials then.

Note that this concept of locating suitable nest materials in advance is more abstract than simply needing something specific for a nest that is under construction. Nests can be built from a variety of materials. In fact it may be that the Phoebe builds its nest based on the materials it has previously located.

I am inclined to think that the instinct to learn like this is widespread in animals. What is especially interesting here is that it is an instinct to learn something highly specialized. This too may well be common. For example, I earlier discussed the horses deciding to explore a new field, that is to learn about it, rather than begin grazing. Then too there is the case of horses changing fields to graze on a particular plant, which they clearly already knew about.

The instinct to learn is certainly a concept worth exploring further.