How to bother a pigeon

My study at home overlooks a small garden and I have been making some very informal and un-Darwin-like observations of the behaviour of birds that have got me thinking about how minor harms are cognized by non-human animals.

Let me give an illustration of the kind of behaviour I am thinking of. At the bottom of the garden is a large tree. Among the species that occasionally rest on their branches are wood pigeons (similar the common city pigeon, but displaying fewer deformities thanks to a diet that does not entirely consist of cigarette ends). I talk about pigeons not because they are interesting in some relevant respect, but simply because they are fairly heavy birds. The relevance of this fact will become apparent soon.

I have repeatedly observed the following behaviour. One individual, 'A' in the (rather crude - sorry) picture below, is resting on a branch.

[PICTURE]

After a while, another individual, 'B', lands on the same branch but further away from the trunk. I don't know whether pigeons' folk physics include principles of leverage, but what inevitably happens is that upon B's landing the branch flexes and A loses balance and starts wildly flapping its wings in an attempt to regain it. Pigeon B does not appear to have chosen the branch in order to interact with A. On no occasion have I seen A expressing its displeasure to B through aggressive displays, although I am no expert in this field and may be missing important behavioural cues; for argument's sake, let us assume that A does not remonstrate.

My question is: what does A make of B's behaviour?

I think it is safe to assume that the human forms of the psychology of responsibility and blame attribution, as well as the guilt/shame response, are not found in pigeons. Yet it is frequently argued in primatology and evolutionary anthropology that most interesting things that humans do can be shown to have precursors in other animals. The problem is that the focus tends to be on behaviours with very significant consequences for the recipients - killing, infanticide, stealing food or sexual partners, etc. I wonder whether looking at more trivial or cases of harm may be revealing. Here are some half-digested ideas on this matter.

There are several different ways A's behaviour can be interpreted. Here are some of them:

1. A is not bothered by B's behaviour;

2. A is somewhat bothered by B's behaviour.

Let's assume that the flapping is indicative of discomfort, and thus that 1 is false. We still don't know whether:

2.1. A does not make the causal connection between B's landing on the branch and the discomfort experienced;

2.2. A understands that B is causally responsible for the discomfort experienced, but does not make an attribution of blame;

2.3. A understands that B is causally responsible for the discomfort experienced, makes an attribution of blame, but does not inflict punishment on B (because of the negligible nature of the discomfort, of the perceived lack of intentionality, etc).

Interpretation 2.1 just seems bizarre to me. Interpretation 2.2 may be better - perhaps A sees B's effects on its being like natural annoyances, such as rain, excessive wind, loud noises, etc. Note that if this were true, this lack of blame attribution could be restricted to minor harms; perhaps pigeons have a higher threshold for blame attribution than do humans, and the connection between act, consequences, and blame is made only where major harms are concerned. Interpretation 2.3. comes with a whole lot of troubling assumptions.

I'd be grateful if others would help me to think through this or suggest sources where the cognition of harms (minor or otherwise) in non-human animals has been discussed.