Sexual Maturity by Sex — Odontoceti (Dolphins)

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In dolphins, males consistently reach sexual maturity later than females. The rough-toothed dolphin has the latest-maturing males (14 years), followed by the common dolphin (13.5 years). Females are earlier in all species — Fraser’s dolphin is the earliest at just 6.5 years. This pattern of later male maturation is linked to sexual competition and reproductive access strategies within social groups.

Chart Data Table

Species	Female (years)	Male (years)
Atlantic spotted dolphin	9	12
Bottlenose dolphin	7.5	10.5
Common dolphin	9	13.5
Fraser’s dolphin	6.5	8.5
Risso’s dolphin	9	11
Rough-toothed dolphin	10	14
Striped dolphin	8	9

References (with hyperlinked sources)

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Alspaugh, M. (2000). “Delphinus delphis” — Animal Diversity Web
Perrin, W. F. (2018). Common Dolphin: Delphinus delphis. In Encyclopedia of Marine Mammals (pp. 205–209). Academic Press. (no public DOI/URL found)
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Hans, K. (2011). “Grampus griseus” — Animal Diversity Web
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Amano, M., Miyazaki, N., & Yanagisawa, F. (1996). Life history of Fraser’s dolphin. Marine Mammal Science, 12, 199–214. https://doi.org/10.1111/j.1748-7692.1996.tb00571.x
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Roca-Monge, K. et al. (2022). Age and Sexual Maturity Estimation of Stranded Striped Dolphins. Oceans, 3, 494–508. https://doi.org/10.3390/oceans3040033
MBM (2021). Fichas de identificação de cetáceos no Arquipélago da Madeira. 66p. (no public URL — recurring, per tracker)
Freitas, L., Dinis, A., Alves, F., Nóbrega, F. (2004). Cetáceos No Arquipélago Da Madeira. Museu da Baleia, Funchal. (no public URL — recurring, per tracker)