Two breeding females within free-living groups may not always indicate polygyny: alternative subordinate female strategies in common marmosets (Callithrix jacchus).
The mating system of callitrichids has been reported to be monogamous, polygynous and polyandrous. In Callithrix jacchus, groups with 2 breeding females and groups with 1 breeding female have been reported. Our purpose was to evaluate the occurrence of occasional reproduction by subordinate females in free-ranging C. jacchus groups characterized as monogamous. Four groups were monitored at a field site of IBAMA-Brazil for between 20 and 72 months. We recorded the birth of 7 sets of twins to subordinate females that had never reproduced before. Sexual activities were recorded opportunistically: dominant females copulated with only the resident male, while subordinates copulated with extra-group males. We suggest these were essentially monogamous groups that occasionally had 2 reproductive females. Between-group copulations seem to be an alternative strategy used by the subordinates. Despite the costs, there would probably be benefits as a result of scanning for vacancies for reproductive positions in neighbouring groups and the establishment of ties with extra-group males that might become a reproductive partner in the future.
Arruda
M F
MF
Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Rio Grande do Norte, Brazil. arruda@cb.ufrn.br
Araújo
A
A
Sousa
M B C
MB
Albuquerque
F S
FS
Albuquerque
A C S R
AC
Yamamoto
M E
ME
D000818:Animals; D002144:Callithrix / Q000502:physiology*; D005260:Female; D008297:Male; D012726:Sexual Behavior, Animal / Q000502:physiology*