Inter-sexual differences in New Zealand fur seal diving behaviour

Page, Brad; McKenzie, Jane; Goldsworthy, Simon

doi:10.3354/meps304249

Cited by 63 publications

(72 citation statements)

References 39 publications

(61 reference statements)

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“…Recent studies on seals confirm that non-breeders typically spend longer at sea on each foraging trip and forage further afield than lactating females (Boyd et al 2002, Sterling & Ream 2004, Ream et al 2005, Page et al 2005a and references therein). Differences in the diet and diving behaviour of lactating female, male and juvenile New Zealand (NZ) fur seals Arctocephalus forsteri in southern Australia indicate that they utilise different prey and that lactating females typically utilise shallower habitats than males (Page et al 2005a,b).…”

Section: Introductionmentioning

confidence: 94%

“…Radford & Du Plessis 2003), gape size in sea-snakes (e.g. Shine et al 2002), costs and benefits associated with storing and transporting body fat and ontogenetic niche shifts in phocid seals (Beck et al 2003, Field et al 2005) and the diet and dive behaviour of fur seals (Robson et al 2004, Sterling & Ream 2004, Page et al 2005a.…”

Section: Discussionmentioning

confidence: 99%

“…Time depth recorders (TDRs, Mk7, Wildlife Computers) were concurrently deployed on 27 females and 13 males (Page et al 2005a), but not on any juveniles. Transmitters were glued to the fur on the dorsal midline, using a flexible-setting epoxy (Araldite 2017, Vantico).…”

Section: Methodsmentioning

confidence: 99%

“…Given that SST and surface chlorophyll concentrations over the continental shelf decreased between autumn and winter, it is likely that tertiary productivity also decreased, compelling some females to invest more time traveling in order to utilise pelagic waters. Interestingly, the diving behaviour of lactating female NZ fur seals and Australian sea lions from Seal Bay (20 km northwest of Cape Gantheaume) also indicates that prey over the continental shelf is harder to utilise in winter (Costa & Gales 2003, Page et al 2005a). Both lactating NZ fur seals and Australian sea lions dived deeper during winter, suggesting that prey were located closer to the benthos or that seals foraged in different regions (Costa & Gales 2003, Page et al 2005a).…”

Section: Lactating Female Foraging Behaviourmentioning

confidence: 99%

“…Interestingly, the diving behaviour of lactating female NZ fur seals and Australian sea lions from Seal Bay (20 km northwest of Cape Gantheaume) also indicates that prey over the continental shelf is harder to utilise in winter (Costa & Gales 2003, Page et al 2005a). Both lactating NZ fur seals and Australian sea lions dived deeper during winter, suggesting that prey were located closer to the benthos or that seals foraged in different regions (Costa & Gales 2003, Page et al 2005a). Based on similar findings of dive depth and distance travelled, Harcourt et al (2002) also suggested that foraging conditions become more difficult for female NZ fur seals in colder months compared to summer.…”

Section: Lactating Female Foraging Behaviourmentioning

confidence: 99%

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Spatial separation of foraging habitats among New Zealand fur seals

Page¹,

McKenzie²,

Sumner³

et al. 2006

Mar. Ecol. Prog. Ser.

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We studied the foraging behaviour of lactating female, adult male and juvenile New Zealand (NZ) fur seals to compare and contrast their foraging strategies and assess the degree of spatial separation of their foraging habitats. Adult male fur seals are longer and heavier than lactating females, which are longer and heavier than juveniles. Trip duration was positively correlated with the distance travelled by all age/sex groups. Juveniles conducted longer trips and travelled further from the colony than males. Both juveniles and males conducted longer trips and travelled further than females, which made brief trips because they were provisioning pups. There were no seasonal differences in the behaviour of males, but females and juveniles foraged closer to the colony in summer when they were moulting and females had younger pups. Behavioural differences were recorded between lactating female, male and juvenile seals in the directional bearing from the colony, the distance travelled, the minimum size of the area that was potentially visited and the horizontal swim speed. Intra-specific foraging competition among these age/sex groups was minimal because lactating females typically used continental shelf waters and males utilised deeper waters over the shelf break, adjacent to female foraging grounds. Furthermore, juveniles used pelagic waters, up to 1000 km south of the habitats used by adults. Differences in the habitats used by females, males and juveniles were also apparent in the seafloor gradient, the SST and the surface chl a concentration, with females using regions with the highest chl a concentrations. Results from this study suggest that smaller seals cannot efficiently utilise prey in the same habitats as larger seals because smaller seals do not have the capacity to spend enough time underwater at the greater depths.

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Section: Introductionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Lactating Female Foraging Behaviourmentioning

confidence: 99%

Section: Lactating Female Foraging Behaviourmentioning

confidence: 99%

See 3 more Smart Citations

Spatial separation of foraging habitats among New Zealand fur seals

Page¹,

McKenzie²,

Sumner³

et al. 2006

Mar. Ecol. Prog. Ser.

Self Cite

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Earthquake impacts on a protected pinniped in New Zealand

Hall,

Chilvers,

Weir

et al. 2024

Aquatic Conservation

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The impacts of natural disasters on marine mammals are poorly understood and difficult to study, which can hamper management responses following such events. This study provides the first distribution and abundance assessment of New Zealand fur seal (NZFS: Arctocephalus forsteri) colonies around Kaikōura, New Zealand, since a 7.8 magnitude earthquake in November 2016 caused substantial changes to both the local marine and terrestrial environments, and led to the reconstruction of a major highway that runs adjacent to NZFS colonies. Mark–recapture and direct counts in the 2022–2023 breeding season estimated pup production for NZFS breeding colonies along the Kaikōura coast. Using established multipliers, pup estimates were used to provide the first comprehensive population estimate for Kaikōura's NZFS population since the earthquake. Three new colonies and three new subcolonies were assessed and recorded, additional to reassessments of two established colonies. Overall, Kaikōura's NZFS population has grown and spread post‐earthquake, with an upper total population estimate of between 21,560 and 28,327 animals in the 2022–2023 breeding season. Some sites, such as Lynch's Reef, appear to have benefited from earthquake‐induced coastal uplift, with pup production increasing. Contrastingly, the estimated 2,401 (±99) pups produced at Ōhau Point in 2023 is similar to pre‐earthquake estimates. This indicates that the earthquake has disrupted previously documented growth at this site. The distribution of NZFS breeding at Ōhau Point has also changed substantially since the last pre‐earthquake assessment. From these findings, alterations to the Ōhau Point New Zealand Fur Seal Sanctuary and similar protections at other locations on the Kaikōura coast are suggested, as greater numbers of NZFSs are now accessible to human interaction and disturbance. The results demonstrate both how natural disasters and subsequent infrastructure modifications can impact coastal species and how conservation measures may need to be amended accordingly.

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Foraging Capacities, Behaviors and Strategies of Otariids and Odobenids

Jeanniard‐du‐Dot

Guinet

2021

Ethology and Behavioral Ecology of Otariids and the Odobenid

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Inter-sexual differences in New Zealand fur seal diving behaviour

Cited by 63 publications

References 39 publications

Spatial separation of foraging habitats among New Zealand fur seals

Spatial separation of foraging habitats among New Zealand fur seals

Earthquake impacts on a protected pinniped in New Zealand

Foraging Capacities, Behaviors and Strategies of Otariids and Odobenids

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