Behavioural research is all about asking questions. Often if you see a difference between different animals (e.g. their age, sex, size, the enclosure that they are kept in, etc.), you might ask how that difference effects the behaviour of the individual:

 

e.g. Does the age of a penguin effect its behaviour?

 

The research study is designed to collect evidence to answer that question. This may involve training the animal to engage with an experiment through positive reinforcement (the animal gets a treat of a food reward every time it engages in the research) or it may simply be observational (watching the animal go about its daily business.