Fig. 3.
Population growth rate means and temporal variabilities for central and marginal populations of M. cardinalis and M. lewisii. (A) Mean asymptotic population growth rate (λ), calculated as the geometric mean of 7 annual λ estimates, for M. cardinalis. (B) Temporal variability in λ, calculated as the geometric standard deviation in 7 annual λ estimates, for M. cardinalis. (C) Mean λ for M. lewisii. (D) Temporal variability in λ for M. lewisii. Error bars show 1 SE of estimates between replicate populations at a given range position. P values are from 2-tailed t tests for central-marginal differences. ns indicates nonsignificant, P > 0.10.