Colony growth and pup condition of the New Zealand fur seal (Arctocephalus forsteri) on the Kaikoura coastline compared with other east coast colonies

2006 ◽  
Vol 33 (6) ◽  
pp. 497 ◽  
Author(s):  
L. J. Boren ◽  
C. G. Muller ◽  
N. J. Gemmell
Keyword(s):  
New Zealand ◽  
Body Condition ◽  
East Coast ◽  
Colony Growth ◽  
The Body ◽  
Fur Seal ◽  
Seal Population ◽  
Condition Indices ◽  
New Zealand Fur Seal ◽  
Breeding Seasons

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.

Changes in the abundance of New Zealand fur seals, Arctocephalus forsteri, on Kangaroo Island, South Australia

1995 ◽  
Vol 22 (2) ◽  
pp. 201 ◽  
Author(s):  
PD Shaughnessy ◽  
SD Goldsworthy ◽  
JA Libke
Keyword(s):  
New Zealand ◽  
South Australia ◽  
Early Years ◽  
Mark Recapture ◽  
Fur Seals ◽  
Fur Seal ◽  
Rate Of Increase ◽  
New Zealand Fur Seal ◽  
Breeding Seasons ◽  
Made In

Kangaroo Island was an important seal-harvesting site during the early years of European colonisation of Australia. A recent survey of the New Zealand fur seal, Arctocephalus forsteri, in South and Western Australia indicates that Kangaroo I. is still an important centre for the species. In order to determine changes in the abundance of the population, numbers of pups were determined at four colonies on Kangaroo Island by mark-recapture in up to five breeding seasons from 1988-89 to 1992-93. Clipping was the preferred technique for mark-recapture estimation of pups because it was quick, easy and effective. Recaptures were conducted visually; they were repeated several times in each season to improve precision of the estimates. No pups were marked between recaptures in order to minimise disturbance. Assumptions made in estimating population size by the mark-recapture technique pertinent to this study are reviewed. Pup numbers increased at three colonies: at Cape Gantheaume, from 458 to 867 over five years (with exponential rate of increase r = 0.16, n = 5); at Nautilus North, from 182 to 376 over five years (at r = 0.19, n = 4); and at North Casuarina Islet, from 442 to 503 over four years (at r = 0.043, n = 2). Rates of increase in the first two colonies are similar to those at the most rapidly increasing fur seal populations in the Southern Hemisphere. The Kangaroo I. population is estimated to be 10000 animals in 1992-93. It is likely to be at the recolonisation phase of growth, with high rates of increase at individual colonies (or parts of colonies) resulting from local immigration. As space does not appear to be limiting expansion in these colonies, fur seal numbers may continue to increase there.

Trends in abundance of New Zealand fur seals, Arctocephalus forsteri, at the Neptune Islands, South Australia

2002 ◽  
Vol 29 (4) ◽  
pp. 363 ◽  
Author(s):  
P. D. Shaughnessy ◽  
A. McKeown
Keyword(s):  
New Zealand ◽  
South Australia ◽  
The South ◽  
The North ◽  
Fur Seals ◽  
Fur Seal ◽  
Seal Population ◽  
Island Group ◽  
Direct Counting ◽  
New Zealand Fur Seal

At the Neptune Islands in early February 2000 at the end of the 1999–2000 pupping season, the abundance of New Zealand fur seal pups was determined using a mark–recapture technique in large colonies and by direct counting in small ones. Pups (n = 2355) were marked by clipping hair on the head to reveal light-coloured underfur. At the North Neptune group, there were 4221 pups and at the South Neptune group 1767 pups, making a total of 5988 pups for the Neptune Island group as a whole. At the North Neptune Islands, pup numbers increased by 53% since February 1993, from 2756 to 4221. For the South Neptune group, pup numbers decreased by 6.7%, from 1893 to 1767. The decrease was spread over most colonies on the island. The large increase in pup numbers at the North Neptune group indicates that the population there is in the recolonisation phase of growth; at the South Neptune group, the fur seal population is likely to be in the maturity phase, with fluctuations in size expected in the future. The Neptune Island group supports the largest aggregation of pinnipeds in Australia.

Changes in the abundance of New Zealand fur seals, Arctocephalus forsteri, on the Neptune Islands, South Australia

1996 ◽  
Vol 23 (6) ◽  
pp. 697 ◽  
Author(s):  
PD Shaughnessy ◽  
I Stirling ◽  
TE Dennis
Keyword(s):  
New Zealand ◽  
South Australia ◽  
Breeding Population ◽  
The South ◽  
Mark Recapture ◽  
The North ◽  
Fur Seals ◽  
Fur Seal ◽  
New Zealand Fur Seal ◽  
Breeding Seasons

The South Neptune Island group is a well-known site for the New Zealand fur seal, Arctocephalus forsteri. A survey of seals in South Australia and Western Australia in the 1989-90 summer indicated that colonies on the South Neptunes and the adjacent North Neptunes group contained half of the breeding population in Australia. The abundance of pups at the South Neptune group was determined in four breeding seasons: 1969-70, 1988-89, 1989-90 and 1992-93. The population on Main Island increased at an exponential rate of r = 0.053 (equivalent to 5.4% per annum) between the first two surveys: counts of pups increased from 487 to 1333, and the breeding area expanded to include several new colonies. Mark-recapture estimates of pup numbers in the two largest colonies in 1989-90 and 1992-93 did not differ statistically. Rates of increase in individual colonies over the 19 or 20 years from 1970 ranged from r = 0.031 (3.1%) to r = 0.256 (29.2%). On the South Neptune Islands, the estimate of pup abundance in the most recent survey (1992-93) was 1916, on the basis of mark-recapture in most colonies and of counting in a few small ones. On the North Neptune Islands, the estimate of pup abundance in 1992-93 was 2756, on the basis of mark-recapture in most colonies. By applying a multiplier of 4.9 to convert pup numbers to an estimate of abundance of the whole population, estimates of 9400 and 13500 fur seals were obtained for the South Neptune and North Neptune Islands in 1992-93, respectively. These estimates provide a firm foundation for comparisons in future years.

Male-biased sex ratios in New Zealand fur seal pups relative to environmental variation

2003 ◽  
Vol 53 (5) ◽  
pp. 297-307 ◽  
Author(s):  
Corey J. A. Bradshaw ◽  
Robert G. Harcourt ◽  
Lloyd S. Davis
Keyword(s):  
New Zealand ◽  
Sex Ratios ◽  
Environmental Variation ◽  
Fur Seal ◽  
New Zealand Fur Seal

Records of vagrant fur seals (family Otariidae) in South Australia

2014 ◽  
Vol 36 (2) ◽  
pp. 154 ◽  
Author(s):  
Peter D. Shaughnessy ◽  
Catherine M. Kemper ◽  
David Stemmer ◽  
Jane McKenzie
Keyword(s):  
New Zealand ◽  
South Australia ◽  
The South ◽  
South Indian Ocean ◽  
Fur Seals ◽  
South Indian ◽  
Fur Seal ◽  
New Zealand Fur Seal ◽  
The Antarctic ◽  
Subantarctic Fur Seals

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.

Effects of habitat and introduced mammalian predators on the breeding success of Yellow-eyed Penguins Megadyptes antipodes, South Island, New Zealand

1999 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Hiltrun Ratz ◽  
Brian Murphy
Keyword(s):  
New Zealand ◽  
Breeding Success ◽  
East Coast ◽  
Marked Effect ◽  
Forest Edge ◽  
Introduced Predators ◽  
Mammalian Predators ◽  
Predator Abundance ◽  
Breeding Seasons ◽  
Predator Guild

The endemic Yellow-eyed Penguin Megadyptes antipodes is threatened by habitat loss and introduced predators on mainland New Zealand. Nine colonies in the Catlins (south-east coast of South Island) were studied to measure breeding success, penguin abundance, and predator abundance in three successive breeding seasons (1991/92 to 1993/94). Nest numbers increased in all nine colonies in the three years despite predation (probably by Stoats Mustefa erminea) being the most important cause of breeding failure. Larger colonies with higher breeding success were in small gullies with limited shrubs and bushes rather than in the most intact mature forest colonies hitherto assumed to be optimal habitat for the birds. Penguin nests were concentrated near the forest edge, but predators were not, so the predation risk was not elevated near the forest edge. Fragmentation of the original forest habitat had no observable adverse effect on breeding success. Stoats dominated the predator guild, while Ferrets M. furo and Feral Cats Felis catus were rare. Trapping to kill predators early in the season had no marked effect on subsequent predation losses, but trapping intervention when a predation outbreak occurred curtailed further chick deaths. A simple population model predicts that Yellow-eyed Penguins populations will grow provided the average total chicks loss is less than 43% per season, or at least 0.85 chick per nest fledges each year. This requires predation losses to be less than 34%.

New Zealand Fur Seal, Taiaroa Head, Otago Peninsula, New Zealand

Spine ◽  
2003 ◽  
Vol 28 (5) ◽  
pp. i
Author(s):  
Jörg Krebs
Keyword(s):  
New Zealand ◽  
Fur Seal ◽  
New Zealand Fur Seal

Pup growth of the New Zealand fur seal Arctocephalus forsteri on the Open Bay Islands, New Zealand

2009 ◽  
Vol 193 (3) ◽  
pp. 305-314 ◽  
Author(s):  
R. H. Mattlin
Keyword(s):  
New Zealand ◽  
Fur Seal ◽  
New Zealand Fur Seal ◽  
Pup Growth ◽  
Bay Islands

scholarly journals Body mass index and glucose variations during the night in free-ranging Artibeus planirostris (Chiroptera: Phyllostomidae)

2019 ◽  
Vol 36 ◽  
pp. 1-8 ◽  
Author(s):  
Luane Maria Melo Azeredo ◽  
Monique Silva Ximenes ◽  
Kleytone Alves Pereira ◽  
Maria Paula Aguiar Fracasso ◽  
Luiz Carlos Serramo Lopez
Keyword(s):  
Blood Glucose ◽  
Body Mass ◽  
Body Condition ◽  
The Body ◽  
Energy Reserve ◽  
Glucose Levels ◽  
Reproductive Phase ◽  
Condition Indices ◽  
Positive Correlations ◽  
Free Ranging

Body condition is an important measure to estimate the energy reserve of an organism. Scientists frequently use body condition indices (BCIs) with morphometric measures but direct measurements, such as blood glucose, seem to be more reliable. We observed oscillations in the body condition and glucose indexes of individuals of Artibeusplanirostris (Spix, 1823) during 13 nights in the field. We assume that if glucose levels are proportional to feeding state and body condition is a measure of energy reserve, blood glucose and BCI should be positively correlated and both are expected to increase during the night as the bats leave their diurnal roost to feed. To test this, we examined the relationship between blood glucose levels, BCI and reproductive phase of free flying male bats (n = 70) for 12 hours after sunset for 13 nights. Bats were captured in Reserva Biológica de Guaribas (Paraíba, Brazil) using mist nets. Blood glucose was analyzed with a portable glucometer. Supporting our assumptions, the number of hours after sunset and BCI presented significant positive correlations with glucose levels in A.planirostris. Reproductive phase did not present a significant correlation with any other variables. As we predicted, glucose level can be used as proxy for morphometric BCI and it can be measured with a simple portable glucometer. The increase both in glucose and BCI around the night can be explained by the efficient assimilation of nutrients present in fruits ingested by bats and the quick metabolism that increases the levels of glucose (an other nutrients) in blood, increasing the body mass.

A survey of the oral cavity microbiome of New Zealand fur seal pups ( Arctocephalus forsteri )

2019 ◽  
Vol 36 (1) ◽  
pp. 334-343 ◽  
Author(s):  
Arsalan Emami‐Khoyi ◽  
Isma Benmazouz ◽  
James G. Ross ◽  
Laura J. Boren ◽  
Elaine C. Murphy ◽  
...  
Keyword(s):  
New Zealand ◽  
Oral Cavity ◽  
Fur Seal ◽  
New Zealand Fur Seal
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