Age is important for studying population dynamics, but it is difficult to obtain reasonably accurate age estimates and associated uncertainty of free-ranging individuals, especially for cetaceans. We developed a protocol for deriving probabilistic age estimates using information commonly curated in marine mammal photo-identification catalogs and applied the approach to 81 biopsy-sampled and genetically sexed false killer whales (Pseudorca crassidens) from the endangered main Hawaiian Islands insular population. The protocol integrates qualitative evidence into a quantitative framework for deriving age estimates and plausible age ranges. Confidence ratings reflecting the strength of available evidence were developed to account for uncertainty. Estimates were then translated to statistical distributions to depict probabilistic age estimates that can be used in further analyses. Age estimates ranged from 3 to 40 years (minimum: 1–33; maximum: 5–65) and were strongly influenced by the estimated age when first seen and length of sighting history. Sensitivity analyses show that population-level age distribution estimates are robust to age class misclassifications and lack of auxiliary information, including sex. This protocol may provide a guide for aging individuals of some species from photo-identification catalogs and for which other aging methods from biological samples are not yet feasible or available.
HŌʻULUʻULU MANAʻO
He mea nui ke kūlana makahiki ma ka nānā ʻana i nā loliō pūʻuo, paʻakikī naʻe ka loaʻa ʻana o ke koho kūlana makahiki pololei a me nā mea kānalua o nā mea holo kūʻokoʻa, keu hoʻi no ka lāhui koholā. Ua hoʻomōhala mākou i ke kiʻinahana no ka hoʻomaulia ʻana i nā koho kūlana makahiki ma o ka nānā ʻana i ka ʻikepili i ʻike nui ʻia ma nā kiʻi hōʻoia o nā māmela kai a ua haʻapili ʻia i nā koholā ʻāhuka iwi poʻo like (Pseudorca crassidens) he 81 i kālailai ʻia kona ʻaʻaʻa hunaola a i waeʻona ʻia ma ke keka ēwe mai loko mai o ka pūʻuo ʻane halapohe a ʻaneʻane puni i ka paeʻāina ʻo Hawaiʻi. Ma ia kiʻinahana, hoʻokomo ʻia ka meheu ana ʻano i loko o ka ʻolokeʻa ana nui no ka loaʻa ʻana i nā koho kūlana makahiki a me ka laulā o nā kūlana makahiki i hiki. Ua hoʻomōhala ʻia nā kūlana hilinaʻi i hōʻike i ka ikaika o nā kolokolo i loaʻa i mea e helu ʻia ai nā kānalua. A laila, unuhi ʻia ia mau kolokolo i mau ili helu no ka ʻike ʻana i nā koho kūlana makahiki ʻoiaʻiʻo paha i hiki ke hoʻohana ʻia no ke kālailai hou aku. Mai ka ʻekolu a i ke 40 makahiki nā koho kūlana makahiki (ʻo ke emi loa: 1–33; ʻo ka nui loa: 5–65) a ua pā nui i ke koho kūlana makahiki i ka makamua o ka ʻike ʻana a pēia pū i ka nui o nā wā i ʻike ʻia. Hōʻike nā kālailaina makaʻala i ka ikaika o ka ili kūlana makahiki ma ka pae pūʻuo no ka hemahema o ka wae kūlana makahiki a no ka lawa ʻole o ka ʻikepili kōkoʻolua, e laʻa hoʻi me ke keka. He alakaʻi paha kēia kiʻinahana no ka hoʻokūlana makahiki i kēlā me kēia o kekahi mau lāhui mai nā waihona kiʻi hōʻoia, a pēlā pū i ka hoʻokūlana makahiki ma o nā ʻano hana ʻaʻaʻa hunaola i hiki ʻole a i loaʻa ʻole paha.
Citation:
Kratofil, M.A., S.D. Mahaffy, K.K. Martien, F.I. Archer, K.L. West, S.J. Chivers, and R.W. Baird. 2025. Deriving Probabilistic Age Estimates Using Common Photo-Identification Catalog Information: An Application to Endangered Hawaiian False Killer Whales (Pseudorca crassidens). Marine Mammal Science, e70080. doi: 10.1111/mms.70080
Link:
https://onlinelibrary.wiley.com/doi/10.1111/mms.70080