Quantifying hens’ startle reflexes

1 08 2016

Misha got some nice data for 12-15 hens in the forceplate experiment he finished about a month ago. The first challenge is now to describe this reflex, as one goal was just to characterise it properly (no-one having done this before for this species).


Looking at vertical forces only (a typical response being sketched above), to mimic what’s obtained in rodent studies, he found that everything happened within about 300ms (= good; what we expected), but that pattern and the duration both differed a lot between birds, total duration varying by about an order of magnitude (= not good; this is supposed to be a very stereotyped response).

We then realised that looking at vertical forces only was naive: these are free-moving, bipedal animals who may well spring forwards or backwards as well as upwards, depending on how they happen to be standing when the flash goes off. So now we’re looking at both z and y forces, trying to work out how to fit them together. This means brushing up on vectors…: slightly intimidating, but maybe also nerdily fun (at least according to “maths is fun”).