Videos:

Species depletion

http://www.youtube.com/watch?v=EPCk7gHzZRI

http://www.youtube.com/watch?v=TZb348uSYZg  4.03 min

Resources:

Janson, C. (2000). Spatial Movement Strategies: Theory, Evidence and Challenges In Boinski, S., and Garber, P.A., ( Ed.), On the Move: How and Why Animals Travel in Groups. Chicago: University of Chicago Press, Ltd.