Individual and seasonal variations of space use in silvertip sharks, Carcharhinus albimarginatus

The silvertip shark, Carcharhinus albimarginatus, is a coral reef-associated shark with a wide distribution across the Indo-Pacific. Yet, unlike common reef shark species, limited knowledge exists on its movement patterns. Here, we tracked 28 individuals for 4 years with acoustic telemetry in New Caledonia to estimate home range sizes and to investigate individual and seasonal patterns of space use. Comparisons were made with grey reef sharks, C. amblyrhynchos, a closely related but more documented species, tagged on the same acoustic network during the same period. We report similar home range (HR) for both species, with adult males displaying greater HR than females and juveniles. An increased mobility of adult males was observed during the austral summer for the silvertip shark, and the austral winter for the grey reef shark, corresponding to putative mating seasons. Our study brings new insight on the ecology of the silvertip shark and provides essential material to inform targeted conservation measures.

Automated summary

In this study, 28 silvertip sharks were tracked using acoustic telemetry for 4 years in New Caledonia to estimate home range sizes and investigate their movement patterns. The results showed that the silvertip shark has similar home range as the grey reef shark, with adult males having larger home ranges than females and juveniles. Additionally, a higher mobility was observed in adult males during the austral summer for silvertip sharks and austral winter for grey reef sharks, corresponding to potential mating seasons. This study provides new insights into the ecology of the silvertip shark and valuable information for targeted conservation measures.