Age structure of a population of Barbarophryne brongersmai (Anura, Bufonidae) inhabiting an arid environment in the Central Jbilets (West-Morocco).
Résumé
We estimated age structure and some life-history traits in a population of Barbarophryne brongersmai at the northern border of the distribution area of this species by using skeletochronology to establish individual age and age at sexual maturity. Maturity was reached at 2-4 years in males and 3-5 years in females, which was late relatively to small body size. Longevity was estimated to be 12 and 8 years for males and females, respectively, whereas mean body size is 45.6 mm in both sexes. However, this estimate suffers from small sample size in females. We did not detect a positive relationship between age and size, suggesting that adult individuals cease growing after maturity. Conversely, body size varied within an age class, suggesting great variability of growth rate among individuals during the juvenile stage. Collectively, these traits characterize a life history strategy that could be an evolutionary response to habitat unpredictability in arid regions.