Ml. Rosenzweig et al., SAFETY IN NUMBERS - SOPHISTICATED VIGILANCE BY ALLENBYS GERBIL, Proceedings of the National Academy of Sciences of the United Statesof America, 94(11), 1997, pp. 5713-5715
Since 1963, nonlinear predation theory has predicted that, at low popu
lation densities, victim species may well be mutualistic rather than c
ompetitive, Theory identifies this mutualism as a principal source of
dynamic instability in the interaction, Using gerbils and trained barn
owls, we conducted the first (to our knowledge) field tests of the th
eory's prediction of mutualism. The behavior of the gerbils confirms i
ts existence.