Cooperative Breeding in Meerkats
Biology 342 Fall 08
Daniel Bernstein and Justine Spencer
How does cooperative breeding work physiologically?
Allonursing is the act of a lactating female suckling non-related pups. In 1999, a study found that allonursing is a relatively common behavior in meerkat groups. Females lactate after giving birth. This study found that subordinate females that had lost their young, whether “perinatal loss due to weather conditions, a subordinate’s inexperience of rearing young, lack of help at the den, or through direct infanticidal manipulation by dominant females” (Doolan and Macdonald 1999), often took on allonursing of other pups. This had the effect of reducing the cost of lactation in successfully breeding females. This study also noted a number of cases of spontaneous lactation. If spontaneous lactation is pheromonally induced by the dominant female in order to co-opt the reproductive capabilities of subordinate females, hormone-pheromone affects would present a major mechanism for cooperative breeding behavior in meerkats.
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In 2001, there was a study performed that attempted to develop a normative reproductive-endocrine database for meerkats (Moss, Clutton-Brock et al. 2001). The researchers analyzed fecal and urinary samples of pregnant and non-pregnant female meerkats in an attempt to match hormonal patterns to reproductive suppression. This study could not make a definitive conclusion as to whether or not the dominant female was “‘physically’ preventing copulation” or preventing reproduction from “direct suppression of ovulation (i.e., chemical, pheromonal, or aggression-related stress)” (Moss, Clutton-Brock et al. 2001).