Mate-guarding is not energy-draining in wild long-tailed macaques
Mate-guarding seems to not be energetically costly in wild male long-tailed macaques. In a study combining behavioural observations with non-invasive measurements of energetic status through urinary C-peptide assessment, we found that reduced energy uptake during mate-guarding was apparently counterbalanced by reduced vertical locomotion, and thus energy expenditure. It therefore still remains unexplained why dominant males of this species do not mate-guard as many females as could be expected; even though this may impair their genetic fitness. Further analyses are underway.
Girard-Buttoz, C., Heistermann, M., Rahmi, E., Marzec, A., Agil, M., Fauzan, P., & Engelhardt, A. (2014). Mate-guarding constrains feeding activity but not energetic status of wild male long-tailed macaques (Macaca fascicularis). Behavioral Ecology and Sociobiology 68: 583-595. DOI: 10.1007/s00265-013-1673-8