Table 1.

Effect of paternal horn length interacting with lamb sex on survival to 1 year of bighorn lambs at Ram Mountain, Canada, 1988–1992 and 1996–2011. Estimates are from a generalized linear mixed model with a binomial error distribution that included mother and father identity and year of birth as random effects. Female lambs were the sex of reference.

variable	estimate	s.e.	z	p
intercept	0.860	0.275	3.134	0.002
father horn length	−0.594	0.308	−1.928	0.054
lamb sex (male)	−0.920	0.383	−2.403	0.016
mother mass gain	0.657	0.202	3.245	0.001
offspring mass	0.419	0.205	2.047	0.041
father horn length × lamb sex (male)	1.189	0.417	2.851	0.004