• Mediterranean monk seal;
  • Monachus monachus;
  • reproductive cycle;
  • lactation;
  • molt;
  • mating;
  • interbirth


Mediterranean monk seals at Cap Blanc, western Sahara, pup annually throughout the year, although births are more frequent in autumn (October). Consequently, subsequent events of the cycle are not seasonal. This lack of synchronicity in reproduction can be attributed to the subtropical location of the colony and the presence of a semipermanent upwelling in the area. This contrasts with the consistency in the timing of parturition of individual females, which results in an interbirth period of one year, which varies by a maximum of only 15 d. The duration of lactation, which can last up to five months, correlates with that of the interbirth period. The interbirth and “molt-to-parturition” periods are relatively constant, and the only part of the cycle that appears to compensate for variation in lactation length is the “weaning-to-molt” period, which correlates negatively with the duration of lactation. As a result of the long lactation period, esrrus probably does not occur at the end of weaning, as it does in most other phocids.