| Autor: |
Bass, Nathan Charles, Day, Joanna, Guttridge, Tristan L., Knott, Nathan A., Brown, Culum |
| Zdroj: |
Marine & Freshwater Research; 2021, Vol. 72 Issue 10, p1445-1456, 12p |
| Abstrakt: |
Limited information exists about the temporal residency patterns of marine predators, especially at the individual level. Temporal partitioning of resources can reduce intra-specific competition, but this has seldom been examined in predators in marine ecosystems. Here, we used 8 years of acoustic telemetry data from 27 receivers deployed in a large coastal embayment to examine the temporal residency of 51 Port Jackson sharks (Heterodontus portusjacksoni), during their breeding season. We found that the residency lengths of male and female Port Jackson sharks on breeding reefs differed throughout the breeding season, with males showing longer residency at the start of the season and females showing longer residency at the end of the season. Port Jackson sharks also showed a 24-h or diel periodicity in their detection patterns. Although the majority of individuals were nocturnal, a small proportion of sharks was detected more frequently during the day, possibly to reduce competition for resources. Surprisingly, there was no difference in the sex ratio nor the size of diurnal and nocturnal individuals. This study provides long-term insight into the temporal residency patterns of mesopredatory sharks at a breeding site and, more broadly, our results highlight the importance of studying temporal variation at the individual level in movement ecology studies. We used acoustic telemetry data of 51 Port Jackson sharks over 8 years to examine temporal variation in their use of breeding aggregation sites. Males and females showed variation in residency length over the breeding season. Individuals typically showed 24-h periodicity in site use, but exhibited variation in the time of day that they were present. These data suggest that individual variation in residency may mediate competition among individuals. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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