Age and body condition affect sex-biased differences in maternal effects in red deer (Cervus elaphus)

Resumen del trabajo presentado al 8th lnternational Deer Biology Congress & International Wildlife Management Symposium, celebrado en Harbin (China) del 27 al 31 de julio de 2014.
In Ungulates, maternal effects occur when the phenotype of the mother influence that of the calf, with a long term relevance in terms of survival, growth or fitness. lt is common a strong effect of the maternal identity, but there is also certain plasticity in these maternal effects related to the maternal condition, experience or senescence. Trivers-Willard and Local Resources Competition are two hypothesis that has repeatedly demonstrate that different relevant aspects of the maternal phenotype (like age, weight, body condition, and dominance status) may affect the offspring sex-ratio: depending on these combination of factors in the mother, it m ay be more interesting (from the point of view of long-term reproductive fitness) to invest preferentially in one sex or the other. For the same reason, once that the sex of the calf is defined the hind m ay make different investment decisions depending on the sex of the calf. We studied how these aspects of the maternal phenotype influenced different relevant aspects of the calves at birth and during the early growth: birth date, birth weight, weight at weaning, and body condition at weaning. The analyses were performed with the objective of finding differences in the maternal investment related to the sex of the calf, and were conducted on 188 births from 75 hinds aged from 2 to 19. Data was collected along S seasons. All the animals involved were born in captivity under natural mating. For each possible effect (on each calf trait), 4 single GLMMs were built (one for each maternal trait) including hind ID and year as random factors, and the best models were selected using Akaike's lnformation Criterion. As expected, hind weight influences calf birth weight (p