https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689129/Mating behaviourMating behaviour was studied in detail by Carroll (1988, 1991, 1993). Reproduction takes place within the aggregation. Males search for mates on the ground and in the canopy, but sit-and-wait searching also occurs, with males remaining stationary until they detect an approaching individual ( Carroll 1991). After approaching, the male mounts the female’s back, attempts intromission, and, if successful, turns around and attains an end-to-end mating position. The pairs generally remain connected for several hours, but duration of copulation is highly variable (from 20 minutes up to 11 days with an average of 20.5±24.5 hours under laboratory conditions). The prolonged copulation is much longer than needed for sperm transfer alone and serves as postinsemination mate guarding ( Carroll 1988, 1991). Female resistance appears not to have a major influence on the duration copulations ( Carroll 1991, 1993, Carroll and Corneli 1995, Zych 2012). Average duration of copulations of virgin females is significantly shorter than those of the same females during subsequent copulations. Under laboratory conditions, duration of the copulation tends to be greater in groups where sex ratios are more male biased because of intense male–male competition ( Carroll 1991). In male-biased populations there is strong positive sexual selection for male body size. In such populations the ratio of large to small males mating mating is greater. Similarly, mating males are significantly larger than single males. These differences are not observed in unbiased populations. The mating advantage of large males results from their increased locomotion activity ( Carroll and Salamon 1995)
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發表於 2016-11-10 12:57:39
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