what is the covariate for a bird to react to an approaching ship why do birds react to a ship when i observe them when does a bird drop off of the ship if bird reacts to approaching ship - how to change distance how to find time dependent distances how to censor covariates when do birds move towards ship what is the relationship between bird and ship in survival analysis how does distance to sea affect a bird why does bird bearing off the bow change as the ship travels censoring and time dependent covariates can the distance of an airplane change as the ship approaches when do birds move from ship to ship how to calculate a bird's relative bearing off a ship which two r variables affect ship speed when a birds reaction changes when sailing is time dependent covariate why use censored time to time what is the relationship between distance and bearing when a bird is on the water? time dependent and fixed covariates