Fig. 2.

Statistical model fits of survival, growth, fertility, and inheritance for male bighorn sheep (model coefficients in Tables S1–S4). (A) Raw data and binomial model fits for male survival as a function of body mass (kilograms). The solid black line shows lamb survival as a function of birth mass at time t, dashed black line shows yearling survival, dotted gray line adult ram survival, and dashed gray line senescent ram survival. Empirical estimates for these data, taken as the first, central, and last third for each age–size group, with SEs are shown as black dots and vertical lines. Confidence intervals shown for each model prediction. (B) Ram reproduced or not as a function of body mass at time t for adults (fitted solid black line) and senescents (fitted dotted black line). This figure is for illustration; mathematical notation for male mating strategy is described in SI Materials and Methods. (C) Development: The fitted black solid line is lamb growth, the dashed gray line yearling growth, and the dashed black line pooled adult and senescent males. (D) Inheritance data plotted, where lamb mass at time t + 1 is a function of pooled adult and senescent ram mass at time t, with fitted linear model as black line.