Behavior test : Handling aggression

If you use this protocol, please cite the following publication where it was first described:

Dubuc-Messier G, Réale D, Perret P & Charmantier A. 2017. Environmental heterogeneity and population divergence in blue tits personality traits. Behavioural Ecology 28 (2): 448-459. (Link)"

Protocol for the handling agression test :

First, get the bird out from the trap; do not record its reaction at this time. Do not put the bird in a bag but settle in a quiet place (e.g. down the ladder) and score right away. Hold the bird using three fingers, just below its belly (see video), its face away from you. 

To score handling agression, follow 2 steps; it should not take more than approximatively 15 seconds.

Step 1 : Approach your finger towards the beak of the bird without touching it (no closer than 1cm). Your finger should move horizontally, going back and forth 5 times. Scores depend on the bird reaction (see below). At this point if the score is not 2 or 3, move to step 2 (of course if the bird scores 2 or 3 you can do the next step for confirmation)

Step 2 : This step is made to separate score 1 from score 0. You need to touch the bird's beak to stimulate the bird, with your finger approaching in the same way you did before; .

Here some videos showing the scale of scores

Score : 3 = Spread feathers of the tail,  wings are open;  repeated attempts to bite.

Score : 2.5 = Intermediate between 3 an 2

Score : 2 = Spread feathers of the tail,  wings are NOT open;  repeated attempts to bite (but less than score 3)



Score : 1.5 = Intermediate between 2 and 1

Score : 1 = Tail and wings are not open; the bird bites only when it is stimulated (step 2).

Score : 0.5 = Intermediate beetwen 1 and 0

Score : 0 =  Tail and wings are not open; no attempt to bite.

Warnings :
- do not confuse a bird who wants to escape with a score 3.
- do not take into account the pain resulting from the bites.
- do not move; set in a quiet place to avoid perturbation around you when you do the test
- sometimes birds have no reaction in step 1 but a strong reaction in step 2. Then score it as a 2.