Phenotypic and genetic characteristics affecting lifetime reproductive success in female Cuvier's, dama and dorcas gazelles (Gazella cuvieri, G. dama and G. dorcas)



Populations of Cuvier's, dama and dorcas gazelles were removed from the western Sahara to the Estacion Experimental de Zonas Aridas, Almeria, Spain, between 1970 and 1975. The life-history records of all the females living between 1970 and 1988 were examined.

Results show that fecundity is lower in young females than in middle-aged females, and that juvenile mortality is higher in fawns of young females. The adult body length of Cuvier's and dorcas gazelles is affected by their early development but this does not apply to the dama gazelle. The adult body length and the birth weight are positively correlated with longevity in female Cuvier's and dama gazelles, but for the dorcas gazelle only birth weight is related to longevity. Juvenile survival and reproductive performance of the three gazelle species studied are not related to adult body length or birth weight.

A high inbreeding coefficient reduces longevity in Cuvier's and dama gazelles but not in the dorcas gazelle. The effect of a high inbreeding coefficient is pronounced in the fecundity and juvenile survival of the female dama gazelle, less pronounced but evident in dorcas gazelle. The effects of inbreeding are minimal in Cuvier's gazelle and are evident only in the twinning rate. This result is surprising in view of the high inbreeding coefficient in Cuvier's gazelle relative to the other two species.

As in many mammals, birth weights in the three species studied are closely related to the probability of survival during the first days of life. One of the causes of decreasing birth weight in male and female offspring of Cuvier's gazelles and in female offspring of dorcas gazelles is their inbreeding coefficient. The inbreeding coefficient of the mother also reduces the offspring's birth weight in both sexes of the dama gazelle, but there is no influence on offspring of Cuvier's or dorcas gazelles. On the other hand, only the birth weight of the male offspring of the dorcas gazelle is influenced by the birth weight of its mother. Mother's age and offspring birth weight are related for male offspring of Cuvier's and dama gazelles.