The ontogeny of diving behaviour in New Zealand fur seal pups (Arctocephalus forsteri)

2005 ◽  
Vol 83 (9) ◽  
pp. 1149-1161 ◽  
Author(s):  
A M.M Baylis ◽  
B Page ◽  
K Peters ◽  
R McIntosh ◽  
J Mckenzie ◽  
...  

This study investigated the development of diving in 21 New Zealand fur seal pups, Arctocephalus forsteri (Lesson, 1828), prior to weaning at Cape Gantheaume, Kangaroo Island. Diving behaviour was examined using time–depth recorders, which were deployed during two time periods, 5 months prior to weaning (n = 6) and 2 months prior to weaning (n = 15). Scats were also examined to assess whether fur seal pups foraged prior to weaning. The maximum dive depth attained was 44 m, while the maximum dive duration was 3.3 min. Immediately prior to weaning, fur seal pups spent a greater proportion of their time diving at night, and concomitantly several measures of diving performance also increased. In general, pups dived successively deeper (6–44 m between June and September), and the average number of dives per day, dive frequency, and vertical distance travelled increased. Prey remains were present in approximately 30% of scats and indicated that some pups were foraging as early as June (5–6 months of age, approximately 4–5 months prior to weaning). Of the scats that contained prey remains, fish (South American pilchard, Sardinops sagax (Jenyns, 1842); Australian anchovy, Engraulis australis (White, 1790); and redbait, Emmelichthys nitidus Richardson, 1845) accounted for 43% of the prey items found, crustaceans accounted for 36%, and cephalopods (Gould's squid, Nototodarus gouldi (McCoy, 1888)) accounted for 20%.

1998 ◽  
Vol 76 (2) ◽  
pp. 350-360 ◽  
Author(s):  
R H Mattlin ◽  
N J Gales ◽  
D P Costa

The dive behaviour of 18 female New Zealand fur seals (Arctocephalus forsteri) from Taumaka, Open Bay Islands, New Zealand (43°52'S, 168°53'E), was recorded during early (summer; December-February), mid (autumn; March-May), and late (winter; June-August) lactation. Mean dive depth, dive duration, and bottom time for dives >=6 m in depth increased from summer through winter. Variation in individual seal dive behaviour within a season accounted for approximately 11, 9, and 11% of the observed difference between seasons in dive depth, dive duration, and bottom time, respectively. Seasonal dive data (mean ± 1 SD) were as follows: summer: dive depth 30 ± 37 m, dive duration 1.4 ± 1.1 min, and bottom time 0.5 ± 0.6 min; autumn: dive depth 54 ± 47 m, dive duration 2.4 ± 1.3 min, and bottom time 1.0 ± 0.8 min; winter: dive depth 74 ± 64 m, dive duration 2.9 ± 1.5 min, and bottom time 1.2 ± 1.1 min. Maximum recorded dive depth was 274 m for a 5.67-min dive in autumn. Maximum duration was 11.17 min for a dive to 237+ m in winter. New Zealand fur seals are the deepest diving fur seal species reported thus far. The estimated theoretical aerobic dive limit was exceeded on 18.4% of dives (range of individual values 0.2-57.8%). Females (n = 12) were ashore about 1.8 days at a time during February through November, and this increased to about 4.3 days during December and January. Average time spent away from the rookery ranged from 3 to 15 days.


2016 ◽  
Vol 8 (3) ◽  
pp. 343-352 ◽  
Author(s):  
Arsalan Emami-Khoyi ◽  
David A. Hartley ◽  
Adrian M. Paterson ◽  
Laura J. Boren ◽  
Robert H. Cruickshank ◽  
...  

2005 ◽  
Vol 304 ◽  
pp. 249-264 ◽  
Author(s):  
B Page ◽  
J McKenzie ◽  
SD Goldsworthy

2011 ◽  
Vol 89 (12) ◽  
pp. 1195-1205 ◽  
Author(s):  
Amélie A. Augé ◽  
B. Louise Chilvers ◽  
Lloyd S. Davis ◽  
Antoni B. Moore

Female New Zealand sea lions ( Phocarctos hookeri (Gray, 1844)) at the Auckland Islands (remnant populations) are the deepest and longest diving otariids. These remnant populations are found at the margin of the historical range of the species. We hypothesized that diving behaviours of animals in the core of their historical range is less extreme owing to a better marine habitat. All female New Zealand sea lions (n = 13, aged 2–14 years) born on the Otago Peninsula (initial recolonising population) were equipped with time–depth recorders during April and May 2008, 2009, and 2010. The mean dive depth was 20.2 ± 24.5 m and mean dive duration was 1.8 ± 1.1 min, some of the lowest values reported for otariids. Otago female New Zealand sea lions did not exhibit two distinct diving specialisations as reported at the Auckland Islands. Otago adult females exceeded calculated aerobic dive limits in 7.1% of dives compared with 68.7% at the Auckland Islands. The contrasting differences in diving behaviour between Otago and the Auckland Islands suggest that Otago represents a better marine habitat for New Zealand sea lions, with food easily accessible to animals of all ages.


2016 ◽  
Vol 8 (3) ◽  
pp. 353-357
Author(s):  
Arsalan Emami-Khoyi ◽  
David A. Hartley ◽  
Adrian M. Paterson ◽  
Laura J. Boren ◽  
Robert H. Cruickshank ◽  
...  

2003 ◽  
Vol 53 (5) ◽  
pp. 297-307 ◽  
Author(s):  
Corey J. A. Bradshaw ◽  
Robert G. Harcourt ◽  
Lloyd S. Davis

2014 ◽  
Vol 36 (2) ◽  
pp. 154 ◽  
Author(s):  
Peter D. Shaughnessy ◽  
Catherine M. Kemper ◽  
David Stemmer ◽  
Jane McKenzie

Two fur seal species breed on the southern coast of Australia: the Australian fur seal (Arctocephalus pusillus doriferus) and the New Zealand fur seal (A. forsteri). Two other species are vagrants: the subantarctic fur seal (A. tropicalis) and the Antarctic fur seal (A. gazella). We document records of vagrant fur seals in South Australia from 1982 to 2012 based primarily on records from the South Australian Museum. There were 86 subantarctic fur seals: 49 specimens and 37 sightings. Most (77%) were recorded from July to October and 83% of all records were juveniles. All but two specimens were collected between July and November. Sightings were prevalent during the same period, but there were also nine sightings during summer (December–February), several of healthy-looking adults. Notable concentrations were near Victor Harbor, on Kangaroo Island and Eyre Peninsula. Likely sources of subantarctic fur seals seen in South Australia are Macquarie and Amsterdam Islands in the South Indian Ocean, ~2700 km south-east and 5200 km west of SA, respectively. There were two sightings of Antarctic fur seals, both of adults, on Kangaroo Island at New Zealand fur seal breeding colonies. Records of this species for continental Australia and nearby islands are infrequent.


1994 ◽  
Vol 45 (4) ◽  
pp. 653 ◽  
Author(s):  
R Gales ◽  
D Pemberton

In Tasmanian waters, fish were the most prevalent prey taxa in the diet of Arctocephalus pusillus dorlferus, with cephalopods occurring less frequently. Occurrence of crustaceans and birds was negligible. Most prey remains of cephalopods were obtained from regurgitates, whereas faeces provided most fish remains. Twenty-five species of fish were identified from faecal and regurgitate samples, with redbait (Emmelichthys nitidus), jack mackerel (Trachurus declivis) and leatherjackets (Monacanthidae) constituting the main prey species. There was an inverse relationship between the occurrence of fish and that of cephalopods in the samples from Bass Strait, with fish predominating in winter and cephalopods in summer. Size estimates of prey indicated that mainly adult fish and squid were eaten. Most samples contained remains of a single species, suggesting the use of monospecific aggregations of prey items.


2006 ◽  
Vol 33 (6) ◽  
pp. 497 ◽  
Author(s):  
L. J. Boren ◽  
C. G. Muller ◽  
N. J. Gemmell

Abstract.Since its near extermination by sealing, the New Zealand fur seal (Arctocephalus forsteri) has been recolonising areas of its former range throughout New Zealand and Australia. This study examined fur seal population growth over four breeding seasons spanning 2002–05 at the Ohau Point and Lynch’s Reef colonies in Kaikoura and the Horseshoe Bay and Te Oka Bay colonies on Banks Peninsula, on the east coast of New Zealand. Estimates of pup numbers were made using mark–recapture techniques and condition indices were used to assess the body condition of pups in each colony. We found that the Ohau Point and Te Oka Bay colonies are growing exponentially (32% and 47% per annum respectively), reaching nearly 600 pups at Ohau Point and 300 pups at Te Oka Bay, whereas Horseshoe Bay appears stable. Pups born at Ohau Point are consistently heavier and in better condition than their Banks Peninsula counterparts despite the faster rate of growth observed at Te Oka Bay. An El Niño event in 2003 coincided with a drop in mass and condition at the Banks Peninsula colonies, but not at the Kaikoura colony. This discrepancy between colonies in response to environmental conditions suggests that colony-specific variables at Kaikoura may provide more favourable conditions for rearing pups than on Banks Peninsula.


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