I'm researching the behaviour of a bird called Brent Goose. I plan to collect data on 100 individuals of geese. My response variable is divided into four categories: feeding, walking, aggression and other. I plan to watch a bird for 5 minutes, and record the total proportion of that 5 mins that is spent feeding, walking, in aggression and doing other. For example, a bird watched for 5 mins might spend a total of 2 mins feeding, 1 min walking, 1 min aggression and 1 min doing other. Predictor variables are all categorical or integers and include: habitat, age and date.
Could someone suggest an appropriate statistical model to analyse these data? In particular, a model that can handle the proportional response variable.