... that animals establish and maintain home ranges: The benefits of maintaining a home range exceed the costs Let CD be the daily costs for an animal, excluding the costs, CR , of monitoring, maintaining, ... J Fried 1992 Helping by juvenile pine voles (Microtus pinetorum), growth and survival of younger siblings, and the evolution of pine vole sociality Behavioral Ecology 4: 32 5 33 3 Powell, R A and ... C P 1990 Non-parametric estimates of interaction from radio-tracking data Journal of Theoretical Biology 1 43: 431 –4 43 Doncaster, C P and D W Macdonald 1991 Drifting territoriality in the red fox...