SARDI Report Series Is an Administrative Report Series Which Has Not Been Reviewed Outside the Department and Is Not Considered Peer-Reviewed Literature

Abundance of New Zealand fur seal pups in the Cape Gantheaume Wilderness Protection Area, Kangaroo Island: 2011-12 breeding season

Simon D Goldsworthy & Peter D Shaughnessy

SARDI Publication No. F2013/000070-1 SARDI Research Report Series No. 735

SARDI Aquatics Sciences PO Box 120 Henley Beach SA 5022

September 2013

Final Report to Nature Foundation SA

Trends in New Zealand fur seals on Kangaroo Island

Abundance of New Zealand fur seal pups in the Cape Gantheaume Wilderness Protection Area, Kangaroo Island: 2011-12 breeding season

Final Report to Nature Foundation SA

Simon D Goldsworthy & Peter D Shaughnessy

SARDI Publication No. F2013/000070-1 SARDI Research Report Series No. 735

September 2013

Trends in New Zealand fur seals on Kangaroo Island

This publication may be cited as: Goldsworthy, S.D.1 and Shaughnessy, P.D.2 (2013). Abundance of New Zealand fur seal pups in the Cape Gantheaume Wilderness Protection Area, Kangaroo Island: 2011-12 breeding season. Final Report to Nature Foundation SA. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2013/000070-1. SARDI Research Report Series No. 735. 22pp.

Cover Photo: Simon D Goldsworthy

1 SARDI Aquatic Sciences, PO Box 120, Henley Beach, SA 5022 2 South Australian Museum, North Terrace, Adelaide, SA, 5000

South Australian Research and Development Institute SARDI Aquatic Sciences 2 Hamra Avenue West Beach SA 5024

Telephone: (08) 8207 5400 Facsimile: (08) 8207 5406 http://www.sardi.sa.gov.au

DISCLAIMER The authors warrant that they have taken all reasonable care in producing this report. The report has been through the SARDI internal review process, and has been formally approved for release by the Research Chief, Aquatic Sciences. Although all reasonable efforts have been made to ensure quality, SARDI does not warrant that the information in this report is free from errors or omissions. SARDI does not accept any liability for the contents of this report or for any consequences arising from its use or any reliance placed upon it. The SARDI Report Series is an Administrative Report Series which has not been reviewed outside the department and is not considered peer-reviewed literature. Material presented in these Administrative Reports may later be published in formal peer-reviewed scientific literature.

© 2013 SARDI This work is copyright. Apart from any use as permitted under the Copyright Act 1968 (Cth), no part may be reproduced by any process, electronic or otherwise, without the specific written permission of the copyright owner. Neither may information be stored electronically in any form whatsoever without such permission.

Printed in Adelaide: September 2013

SARDI Publication No. F2013/000070-1 SARDI Research Report Series No. 735

Author(s): Simon D Goldsworthy1 & Peter D Shaughnessy2

Reviewer(s): Charlie Huveneers & Alex Dobrovolskis

Approved by: Dr Jason Tanner Science Leader – Marine Ecosystems

Signed:

Date: 26 September 2013

Distribution: Nature Foundation SA, SAASC Library, University of Adelaide Library, Parliamentary Library, State Library and National Library

Circulation: Public Domain II

Trends in New Zealand fur seals on Kangaroo Island

TABLE OF CONTENTS

TABLE OF CONTENTS ...... 1 1 EXECUTIVE SUMMARY ...... 2 2 INTRODUCTION ...... 3 3 METHODS ...... 4 Colonies ...... 4

Direct counting ...... 4

Mark-recapture estimation - marking ...... 5

Mark-recapture estimation - recapturing ...... 5

Dead pups ...... 5

Calculation of mark-recapture estimates ...... 6

Pup weighing ...... 7

4 RESULTS AND DISCUSSION ...... 8 Pup marking ...... 8

Berris Point colony ...... 8

Cape Gantheaume colony ...... 8

Pup mortality ...... 9

Weight of New Zealand fur seal pups ...... 10

Future surveys ...... 10

5 ACKNOWLEDGMENTS ...... 11 6 REFERENCES ...... 12

Trends in New Zealand fur seals on Kangaroo Island

1 EXECUTIVE SUMMARY

Fur seal populations were eliminated over much of their range in southern Australia by early colonial sealers in the early parts of the 19th century. Almost a century and half later, these populations are finally recovering. The best and most continuous data set on the recovery of New Zealand fur seals (Arctophoca forsteri) in Australia comes from the long-term monitoring program in Cape Gantheaume Wilderness Protection Area on Kangaroo Island over 24 consecutive breeding seasons. The project aimed to continue this monitoring program by undertaking pup production surveys using the mark-recapture procedure for large colonies and direct counting for small aggregations of pups in January 2012.

At the Berris Point colony, the estimate was 1,284 pups with 95% confidence limits of 1,256 and 1,312, and at the Cape Gantheaume colony, the estimate was 3,573 pups with 95% confidence limits of 3,523 and 3,624. Another 31 pups were counted at Cape Linois. For all breeding sites monitored in the Cape Gantheaume Wilderness Protection Area, the total estimate of pup numbers for the 2011-12 breeding season was 4,888. This was an increase of 5.3% on the estimate for the previous pupping season (of 4,632 pups), and a large increase (41%) over the estimate for the season before that (2009-10), of 3,475 pups.

Since the study began in January 1989, pup numbers in the Cape Gantheaume Wilderness Protection Area have increased by a factor of 10.7 (from 457 to 4,888). Overall, this increase has been at a rate of 10.6% per annum (n = 25 seasons, r2 = 0.95).

New Zealand fur seal pups were weighed at Cape Gantheaume on 27 January 2012. Males averaged 6.7 kg and females 6.4 kg; the difference between the sexes was not statistically significant. These mean weights are lighter than the long-term averages (-12.0% and -6.6%, respectively).

Trends in New Zealand fur seals on Kangaroo Island

2 INTRODUCTION

Fur seal populations in southern Australia were heavily exploited by colonial sealers between 1801 and 1830, resulting in a major reduction in range and abundance (Kirkwood and Goldsworthy 2013). Numbers remained at very low levels for almost 140 years, when they slowly began to build up and new colonies across their former range were established. The New Zealand fur seal (NZFS, Arctocephalus forsteri) is now well established in South Australia, and there are smaller populations in the other southern states. The Australian fur seal (A. pusillus doriferus) is well established in Victoria and Tasmania, and there are small populations in South Australia and New South Wales. The most detailed information on this recovery of fur seal populations in Australia comes from pup abundance surveys conducted at colonies on Kangaroo Island, South Australia. Recovery of populations of the two fur seal species has benefitted from protection to the breeding colonies by State and Commonwealth governments.

The abundance of pups of the NZFS was determined annually on Kangaroo Island in breeding colonies at Cape Gantheaume (south-eastern point) and Cape du Couedic (south-western point) in late January between 1989 and 2008. In 2008, a strategic decision was made in discussions with the Department of Environment, Water, and Natural Resources (DEWNR) on Kangaroo Island to restrict annual monitoring to breeding sites within the Cape Gantheaume Wilderness Protection Area, making it the main reference colony for annual trends in abundance within South Australia, while Cape du Couedic and other colonies around South Australia would be monitored every 3-5 years. This decision was made because of the increasing requirement for resources as the fur seal population size increased.

Annual monitoring within the Cape Gantheaume Wilderness Protection Area has been conducted each January between 1989 and 2011 (24 years). For the first 12 years of this monitoring program, the mean rate of increase was 15% per year. Over the whole study period pup production has increased by an order of magnitude from 457 to 4,632, equivalent to a 10.8% mean increase per year (Shaughnessy 2011). The abundance estimates are directed at pups because they form the only age-class that is easily recognisable and all of them are ashore together. Although the relationship between the number of pups and the total population size is variable, depending on the status of the population, pup numbers form a useful index of population size (Berkson and DeMaster 1985).

Trends in New Zealand fur seals on Kangaroo Island

In addition, a sample of pups has been weighed and sexed each year at the Cape Gantheaume colony so that it will be possible to compare the trend in pup weights with the trend in pup population size.

The objectives of the study were to determine the number of NZFS pups in breeding colonies in the Cape Gantheaume Wilderness Protection Area, Kangaroo Island in the 2011-12 breeding season using the mark-recapture procedure. This will extend the time-series on pup production to 25 consecutive seasons.

3 METHODS

Colonies

Within the Cape Gantheaume Wilderness Protection Area, there are two large NZFS breeding colonies: Berris Point and Cape Gantheaume (Figure 1). For this project, the Berris Point colony was divided into three sectors referred to as North, Middle and South, separated by deep channels extending through the schist to the base of the limestone slopes (Figure 1). The Cape Gantheaume colony was also separated into sectors as described by Shaughnessy (2000) (Figure 1). The sector boundaries were chosen where there are natural breaks in the colonies that tend to be avoided by pups. In addition, there are several small aggregations of NZFS: (i) west of the Cape Gantheaume colony on small sandy beaches at the base of limestone cliffs, (ii) in the bay immediately north-east of the Cape Gantheaume colony that is known locally as Little Weirs Cove and (iii) at Cape Linois in the north-east section of the Cape Gantheaume Conservation Park. These sites are all within the Cape Gantheaume Wilderness Protection Area.

Direct counting

Pups in small aggregations of NZFS can be counted reasonably accurately and it is not appropriate to estimate their abundance by the mark-recapture procedure because the pups tend to be widely spread and hence marked and unmarked pups would not mix well. Pups in such aggregations were counted by one or two people while walking through them; these are referred to as 'direct counts' to distinguish them from the mark-recapture estimates.

Trends in New Zealand fur seals on Kangaroo Island

Mark-recapture estimation - marking

New Zealand fur seal pups were marked by clipping the black natal hair (lanugo) on the top of their heads between the eyes and down toward the nose, with curved surgical scissors to reveal light grey underfur. This is a temporary mark, in that the natal hair is shed in about March - April, when the adult-type pelage emerges. The marking effort was distributed uniformly throughout the sectors of each colony: pups were marked by a team of people plus a person recording while they moved through each breeding colony catching a sample of accessible pups. We aimed to mark about 45 per cent of pups in each colony in 2011-12 because this provides a reasonably precise estimate with narrow confidence limits.

Mark-recapture estimation - recapturing

The recapture part of the mark-recapture procedure was conducted visually without handling the pups. Recapture sessions were conducted by a single person walking through each colony scanning pups' heads for signs of the clip mark. Information was recorded on tally-counters, one in each hand, with one to record marked pups and the other for unmarked pups. At the completion of each sector, data were recorded in a field notebook and tally-counters reset to zero. The recaptures were considered as ‘resightings’ because the pups were not handled. There were seven recapture sessions at each colony, at least half an hour apart. Recapture sessions began a day or more after pups had been marked to enhance the mixing of marked and unmarked pups.

By distributing marks and conducting recapture sessions uniformly within each sector and throughout the entirety of each breeding colony, the sampling process at resighting should be random with respect to the marking process, which is an important assumption of mark-recapture estimation. The sampling was done without replacement; in other words, care was taken to avoid recording pups more than once in each recapture session.

Dead pups

In each colony, dead pups were recorded when pups were marked, and marked with spray paint. Dead pups were also counted at recapture sessions, and were recorded as being ‘marked’ or ‘unmarked’.

Trends in New Zealand fur seals on Kangaroo Island

Calculation of mark-recapture estimates

Cape Gantheaume and Berris Point colonies were divided into several sectors making use of natural breaks in the colonies in order to improve the precision of the estimates. Pup numbers for each sector (N) were calculated for each sector using a variation of the Petersen method (Seber 1982), with the formula

(Mn 1)( 1) N 1, (m  1) where: M is the number of marked pups at risk of being sampled during recapture operations n is the number of pups examined in the recapture sample, and m is the number of marked pups in the recapture sample.

The variance of this estimate was calculated from

(M 1)( n  1)( M  m )( n  m ) var(N ) . (mm 1)2 ( 2)

Since there were several mark-recapture estimates (Nj) for each sector, one from each recapture session, they were combined by taking the mean (N) for each sector using formulae from White and Garrott (1990, pp. 257 & 268):

q N j N   , j1 q where q was the number of estimates for the individual sector (i.e., the number of recapture sessions). The variance of this estimate for a sector was calculated from:

1 q var(NN ) var( ). 2  j . q j1

Following Chapman 1952, Fowler et al. 1998 and Kuno 1977, the square root of Var(N) gives the standard error (SE) for the estimate, and the 95 % confidence limits are calculated as:

N  (1.96*SE) .

Trends in New Zealand fur seals on Kangaroo Island

Estimates for the whole of the Cape Gantheaume and Berris Point colonies were obtained by summing the estimates for each of their sectors. The variances of those combined estimates were obtained by summing the variances of each sector. The standard error was calculated by taking the square root of that variance.

For each colony, the number of dead pups was added to the estimate of the number of live pups to give the overall estimate of pup numbers in a colony.

The rate of change in pup numbers was calculated using linear regression of the natural logarithm of the mean estimate of pup numbers against year. This gives an exponential rate of increase, which has been demonstrated for New Zealand fur seals on Kangaroo Island (Shaughnessy et al. 1995) and for other species. The exponential rate of increase (r) is the slope of the regression line. It is expressed as a percentage increase using the formula:

(er-1) * 100

Means are presented as ± standard error (s.e.).

Pup weighing

On 27 January 2012, 111 pups were weighed and sexed at Cape Gantheaume.

Trends in New Zealand fur seals on Kangaroo Island

4 RESULTS AND DISCUSSION

Pup marking

A total of 2,617 pups were marked at the NZFS colonies, 694 at Berris Point and 1,923 at Cape Gantheaume (Table 1). All pups were marked on 24 and 25 January 2012.

Berris Point colony

The mark-recapture procedure was based on 694 marked pups. Overall, the mean proportion of marked pups in seven recapture sessions was 0.54. The estimated pup production for the whole colony was 1,284 with s.e. ± 14.4 (Table 2) and 95% confidence limits of 1,256 and 1,312. This estimate included eight pups found dead at marking or during recapture sessions, and nine pups counted north of the mark-recapture area.

Cape Gantheaume colony

The mark-recapture procedure was based on 1,923 marked pups. Overall, the mean proportion of marked pups in seven recapture sessions was 0.55. The estimated number of pups (live + dead) across all sectors totalled 3,487 ± 25.6 (Table 3). The estimate includes 45 pups found dead at marking and during recapture sessions. With the addition of another 22 pups in the sandy coves west of Beach sector, 22 pups in the cave at the headland between the Beach sector and sector A, and 42 pups on rock platforms extending north-east from Little Weirs Cove, the estimate for Cape Gantheaume becomes 3,573 pups, with 95% confidence limits of 3,523 and 3,624 pups.

Mean estimates of pup numbers (live plus dead pups) per sector of the colony were (Table 3): Beach sector, 792 cave between Beach sector and sector A, 22 sector A + B, 115 sector C + D + E, 320 sector F + G + H, 298 sector I + J, 862 sector K + L, 1100.

Trends in New Zealand fur seals on Kangaroo Island

At Cape Linois, 30 live pups were counted on 27 January and a dead pup was seen on 18 January.

For the Cape Gantheaume Wilderness Protection Area, the estimate of pup numbers is 4,888, based primarily on mark-recapture estimates (Table 4). This is an increase of 5.3% on the estimate for the previous pupping season for that area (of 4,632 pups), and a large increase (41%) over the estimate for the season before that (2009-10) of 3,475 pups (Figure 2).

At Cape Gantheaume, estimates of pup numbers increased from January 1989 to January 2012 throughout the colony (Table 5). Since January 1989, pup numbers within the Cape Gantheaume Wilderness Protection Area have increased by a factor of 10.7 (from 457 to 4,888). Overall, this increase has been at an average exponential rate of r = 0.100, equivalent to 10.6% per annum (n = 25 seasons, r2 = 0.95). This is slightly lower than the rate of increase for the 24 seasons to January 2011 of 10.8% per annum.

Pup numbers for Cape Gantheaume and Berris Point increased over the first 12 summers from January 1989 to January 2000, decreased markedly in January 2001, and recovered in January 2002 to levels slightly larger than recorded previously (Figure 2). From January 2002 to January 2012, numbers have generally increased but with decreases in January of 2008 and 2010 followed by marked increases the following summers. The variation may be related to changes in marine conditions several months before the fur seal pupping season in waters south of Kangaroo Island where adult females feed (Page et al. 2006, Baylis et al. 2008). Associated with the decrease in pup numbers at Cape Gantheaume in the 2000-01 pupping season, Goldsworthy et al. (2005) noted an increase in sea surface temperatures south of the colony several months before pups were born. These changes and possible effects of environmental signals deserve further investigation.

Pup mortality

In all, 46 dead New Zealand fur seal pups were recorded, 45 at the Cape Gantheaume and Berris Point colonies (Table 1) and one at Cape Linois. These represent 0.94% of the pups in those colonies (from Table 4).

Trends in New Zealand fur seals on Kangaroo Island

This level of pup mortality is similar to that recorded at colonies on Kangaroo Island in several recent breeding seasons: 1.47% in January 2005 (Shaughnessy 2005, p. 11), 1.93% in January 2006 (Shaughnessy 2006, p. 10), 0.63% in January 2007 (from Shaughnessy and Goldsworthy 2007), 0.90% in January 2009 (Shaughnessy 2009, p. 8) and 1.63% in January 2011 (Shaughnessy 2011, p. 11). It is considerably lower than levels in three seasons when pup numbers decreased compared with the previous season: 2.74% in January 2001 (Shaughnessy and Dennis 2001, p. 9), 2.76% in January 2008 (Shaughnessy 2008, p. 12) and 3.30% in January 2010 (Shaughnessy 2010, p. 7).

These estimates of pup mortality should all be considered underestimates because some of the dead pups would have been overlooked; this would include some that might have been washed out to sea or into rock pools, or taken by scavenging gulls.

Weight of New Zealand fur seal pups

Pups were weighed at Cape Gantheaume on 27 January 2012 (Table 6): males averaged 6.72 kg and females 6.40 kg. These mean weights are less than the long-term averages, by 0.91 kg and 0.45 kg for males and females, respectively.

On 27 January 2012, the difference in weight of pups of the two sexes was not statistically significant: (P = 0.16, with 109 degrees of freedom). Male pups at Cape Gantheaume have been significantly heavier than females in all previous breeding seasons. Fur seals are dimorphic for body size and the males are polygynous; the difference in body size is apparent even in pups.

Future surveys

Since the 2011-12 survey, funding has been received from DEWNR to undertake subsequent NZFS surveys in the Cape Gantheaume Wilderness Protection Area until the 2014-15 breeding season. In addition, funding has been received from the Australian Marine Mammal Centre to undertake a State-wide survey of NZFS in January – February 2014. Both projects will provide a means to improve the understanding of the status and trends in abundance of NZFS populations in South Australia.

Trends in New Zealand fur seals on Kangaroo Island

5 ACKNOWLEDGMENTS

Many people assisted with this project on the New Zealand fur seal in January 2012, for which we are grateful. They included the following staff of SA Department of Environment, Water and Natural Resources on Kangaroo Island who assisted with logistical arrangements: Robert Ellis, Anthony Maguire and Alison Buck.

Thanks are also extended to the following people who assisted in the fur seal colonies: Alison Buck, Peter Greenfield, Lilly Griffith, Victoria Dixon, Annette Florance (DEWNR, Kangaroo Island), Simon Hone (Canberra), Paul Rogers (SARDI Aquatic Sciences), Paul Deighton and Alex Ross (Adelaide), Bruce Buck, James and Andy Doube, and Jen Child (Kangaroo Island).

The work was conducted under PIRSA Animal Ethics Committee permit (23/05, valid to Jan 2014). Permission to conduct the project and to work in the Cape Gantheaume Wilderness Protection Area and Cape Gantheaume Conservation Park was granted by the SA Department of Environment, Water and Natural Resources (A24684-8).

Trends in New Zealand fur seals on Kangaroo Island

6 REFERENCES

Baylis, A. M. M., Page, B. and Goldsworthy, S. D. (2008.). Colony-specific foraging areas of lactating New Zealand fur seals. Marine Ecology Progress Series 361, 279-290.

Berkson, J. M. and DeMaster, D. P. (1985). Use of pup counts in indexing population changes in pinnipeds. Canadian Journal of Fisheries and Aquatic Sciences 42, 873-879.

Chapman, D. G. (1952). Inverse, multiple, and sequential sample censuses. Biometrics 8, 286-306.

Fowler, J., Cohen, L. and Jarvis, P. (1998). ‘Practical Statistics for Field Biology’. (John Wiley and Son Ltd: Chichester, England).

Goldsworthy, S.D., Page, B., and Ward, T (2005) Establishing methods for comparing growth rates and reproductive success of key predators in the eastern GAB. In: Ward T, Goldsworthy, S. D. and Page, B. C. (eds) Trophodynamics of the GAB: Assessing the Need for an Ecological Allocation in the SA Pilchard Fishery. Final report to the FRDC, PN 2003/072. 161 pp.

Kuno, E. (1977). A sequential estimation technique for capture-recapture censuses. Research in Population Ecology 18, 187-194.

Page, B., McKenzie, J., Sumner, M. D., Coyne, M. and Goldsworthy, S. D. (2006). Spatial separation of foraging habitats among New Zealand fur seals. Marine Ecology Progress Series 323, 263-279.

Seber, G. A. F. (1982). ‘The Estimation of Animal Abundance and Related Parameters.’ (MacMillan: New York.)

Shaughnessy, P. (2000). Seal research in South Australia, 1999/2000: abundance of New Zealand fur seal pups on Kangaroo Island and the Neptune Islands. Report to National Parks and Wildlife, South Australia, Department of Environment and Heritage, 39 pp.

Shaughnessy, P. (2005). Population assessment of New Zealand fur seals and Australian sea lions at some colonies in South Australia, 2004-05. Report to Department for Environment and Heritage [South Australia]. 48 + xi pp., December 2005.

Shaughnessy, P. (2006). Population assessment of fur seals and sea lions at some colonies in South Australia, 2005-06. Report to Department for Environment and Heritage, South Australia. 33 pp., April 2006.

Shaughnessy, P. (2008). Population assessment of fur seals and sea lions at some colonies in South Australia, 2007-08. Report to Department for Environment and Heritage, South Australia and the South Australian Wildlife Conservation Fund. 43 pp., May 2008.

Shaughnessy, P. (2009). Trends in the abundance of New Zealand fur seal pups on Kangaroo Island, South Australia, 2008-09. Report to Department for Environment and

Trends in New Zealand fur seals on Kangaroo Island

Heritage, South Australia and the South Australian Wildlife Conservation Fund. June 2009. 22 pp.

Shaughnessy, P. D. (2010). Abundance of New Zealand fur seal pups on Kangaroo Island in 2009-10 and of Australian sea lion pups at The Pages Islands in 2009. Report to Department for Environment and Heritage, South Australia. 35 pp.

Shaughnessy, P.D. (2011) Abundance of New Zealand fur seals pups on Kangaroo Island in 2010-11. Report to the Department of Environment and Natural Resources, South Australia. April 2011, 34 pp. Shaughnessy, P. and Dennis, T. (2001). Research on New Zealand fur seals and Australian sea lions in South Australia, 2000-2001. Report to National Parks and Wildlife South Australia, Department for Environment and Heritage. 44 pp.

Shaughnessy, P. D. and Goldsworthy, S. D. (2007). Population assessment of fur seals and sea lions at some colonies in South Australia, 2006-07. Final report to the Department for Environment and Heritage, South Australia and the South Australian Wildlife Conservation Fund. SARDI Aquatic Sciences Publication Number: F2007/000750-1. SARDI Research Report Series Number: 236. 43 pp.

Shaughnessy, P. D., Goldsworthy, S. D. and Libke, J. A. (1995). Changes in the abundance of New Zealand fur seals, Arctocephalus forsteri, on Kangaroo Island, South Australia. Wildlife Research 22, 201-215.

White, G. C. and Garrott, R. A. (1990). 'Analysis of Wildlife Radio-tracking Data'. (Academic Press: San Diego).

Trends in New Zealand fur seals on Kangaroo Island

Table 1. Numbers of New Zealand fur seal pups marked at breeding colonies in Cape Gantheaume Wilderness Protection Area, Kangaroo Island in January 2012. Pups were marked by clipping hair on the head.

Date No. Dead Dead Colony marked (found at (found at marking) recapture, missed at marking)

Berris Point North 22 Jan 336 1 2 Middle 22 Jan 207 1 1 South 22 Jan 151 1 2 Subtotal 694

Cape Gantheaume Sector Beach 22 Jan 431 5 1 Sector A, B 23 Jan 64 2 2 Sector C, D, E 23 Jan 180 3 1 Sector F, G, H 23 Jan 171 4 1 Sector I, J 23 Jan 506 7 3 Sector K, L 23 Jan 571 16 0 Subtotal 1,923

Total 2,617 40 13

Trends in New Zealand fur seals on Kangaroo Island

Table 2. Mark-recapture estimates of New Zealand fur seal pups at Berris Point colony, Cape Gantheaume Wilderness Protection Area, Kangaroo Island, in January 2012.

Caller No. No. No. marked Pup population Standard marked pups pups estimate error pups examined recaptured (N) (M) (n) (m)

North sector S Goldsworthy 336 287 174 554 18.2 S Hone 336 216 118 614 30.3 A Buck 336 241 128 631 29.8 P Deighton 336 273 141 649 28.7 A Ross 336 218 122 599 28.4 B Buck 336 262 138 637 28.4 P Rogers 336 294 157 628 24.8 Mean estimate 616 Dead pups 3 Mean estimate including dead pups 619 10.29

Middle sector S Goldsworthy 207 155 93 344 16.5 S Hone 207 117 72 335 19.4 A Buck 207 130 77 348 19.8 P Deighton 207 159 92 357 17.8 A Ross 207 121 74 337 19.3 B Buck 207 179 101 366 17.0 P Rogers 207 154 92 346 16.8 Mean estimate 348 Dead pups 2 Mean estimate including dead pups 350 6.85

South sector S Goldsworthy 151 146 62 354 25.6 S Hone 151 145 71 307 18.6 A Buck 151 100 59 255 16.2 P Deighton 151 142 74 289 16.3 A Ross 151 125 54 347 27.9 B Buck 151 153 75 307 17.7 P Rogers 151 180 103 264 9.5 Mean estimate 303 Dead pups 3 Mean estimate including dead pups 306 7.44

Sum of sectors (including dead pups) 1275 North of mark-recapture area (direct count) 9 Total, Berris Point 1284 14.43

Trends in New Zealand fur seals on Kangaroo Island

Table 3. Mark-recapture estimates of New Zealand fur seal pups in sectors at Cape Gantheaume colony, Cape Gantheaume Wilderness Protection Area, Kangaroo Island in January 2012.

Caller No. marked No. pups No. marked Pup population Standard pups examined pups recaptured estimate error (M) (n) (m) (N)

Beach sector S Goldsworthy 431 275 159 744 30.2 S Goldsworthy 431 302 175 743 27.9 S Hone 431 255 143 767 34.4 P Deighton 431 246 134 789 37.8 A Ross 431 167 104 690 35.8 B Buck 431 270 139 835 40.3 P Rogers 431 290 134 930 48.5 Mean estimate 786 Dead pups 6 Mean estimate including dead pups 792 13.97

Sector AB A Buck 64 50 32 99 7.2 S Goldsworthy 64 40 25 102 9.2 S Hone 64 32 21 97 9.5 P Deighton 64 35 19 116 14.2 A Ross 64 31 18 108 13.1 B Buck 64 40 18 139 19.3 P Rogers 64 48 26 117 11.4 Mean estimate 111 Dead pups 4 Mean estimate including dead pups 115 4.75

Sector CDE A Buck 180 153 90 305 14.4 S Goldsworthy 180 142 87 293 13.9 S Hone 180 116 74 281 14.9 P Deighton 180 137 71 346 21.8 A Ross 180 128 74 310 17.7 B Buck 180 141 80 316 17.1 P Rogers 180 171 85 361 19.9 Mean estimate 316 Dead pups 4 Mean estimate including dead pups 320 6.54

Trends in New Zealand fur seals on Kangaroo Island

Table 3 (continued)

Caller No. marked No. pups No. marked Pup population Standard pups examined pups recaptured estimate error (M) (n) (m) (N)

Sector FGH A Buck 171 135 83 277 13.4 S Goldsworthy 171 130 74 299 16.9 S Hone 171 102 71 245 12.0 P Deighton 171 103 59 297 20.0 A Ross 171 87 48 308 24.6 B Buck 171 118 64 314 20.6 P Rogers 171 147 80 313 17.0 Mean estimate 293 Dead pups 5 Mean estimate including dead pups 298 6.89

Sector IJ S Goldsworthy 506 377 226 843 26.3 S Hone 506 247 146 854 37.8 A Buck 506 254 164 783 29.7 P Deighton 506 293 173 856 33.5 A Ross 506 304 172 893 36.2 B Buck 506 382 221 874 28.5 P Rogers 506 442 259 863 24.0 Mean estimate 852 Dead pups 10 Mean estimate including dead pups 862 11.80

Sector KL S Goldsworthy 571 517 264 1117 35.1 S Hone 571 368 194 1081 43.1 A Buck 571 356 208 976 34.6 P Deighton 571 363 192 1078 43.2 A Ross 571 363 183 1131 48.2 B Buck 571 498 256 1110 35.7 P Rogers 571 709 370 1094 23.2 Mean estimate 1084 Dead pups 16 Mean estimate including dead pups 1100 14.49

Sum of sector means 3,487 West of Beach sector (direct count) 22 Cave at the Cape (direct count) 22 Little Weirs (direct count) 42 Overall total 3,573 25.63

Trends in New Zealand fur seals on Kangaroo Island

Table 4. Summary of abundance estimates of New Zealand fur seal pups in breeding colonies in the Cape Gantheaume Wilderness Protection Area, Kangaroo Island in January 2012.

Pup numbers Breeding colony Method of Live Dead a Total estimation

Cape Hart Direct counting - - - Cape Linois Direct counting 30 1 31 Berris Point Mark-recapture 1276 8 1284 Little Weirs & nearby Direct counting 42 0 42 Cape Gantheaume Mark-recapture 3464 45 3509 Cape Gantheaume, Direct counting 22 0 22 west of colony 4,888 Total a Includes some dead pups found during recapture sessions.

Trends in New Zealand fur seals on Kangaroo Island

Table 5. Numbers of New Zealand fur seal pups in sectors of the Cape Gantheaume colony, and other sites within the Cape Gantheaume Wilderness Protection Area, Kangaroo Island in 24 breeding seasons to 2011-12. Dead pups are included. Data up until 2010-11 from Shaughnessy (2011) and previous reports. Data for 2011-12 are from Table 3 of this report. Dashes (-) denote no survey.

Sectors Little Berris Cape Year Beach Beach Cave A, B C, D, E F to L Wiers Point Linois Overall (west) Cove

1988-89 0 0 233 205 19 457 1989-90 0 0 237 234 54 525 1990-91 0 0 279 238 89 606 1991-92 2 0 312 310 112 736 1992-93 2 0 370 313 179 864 1993-94 22 0 380 311 225 938 1994-95 92 0 350 409 263 1114 1995-96 211 6 337 426 425 1405 1996-97 341 0 275 478 485 4 1583 1997-98 548 12 270 408 694 11 1943 1998-99 623 0 201 402 822 17 2065 1999-2000 590 8 132 408 994 22 2154 2000-01 523 5 73 222 832 66 1722 2001-02 633 22 71 289 1117 109 1 2241 2002-03 618 33 71 310 1138 143 - 2313 2003-04 692 45 85 370 1443 264 - 2899 2004-05 750 41 92 394 1704 460 - 3441 2005-06 14 731 41 106 360 1883 697 2 3834 2006-07 11 690 41 100 314 1817 850 - 3823 2007-08 13 635 9 100 293 1782 849 3 3685 2008-09 7 804 - 107 347 2079 7 1110 - 4461 2009-10 21 548 28 72 261 1671 - 868 4 3472 2010-11 27 707 28 100 319 2177 12 1248 6 4624 2011-12 22 792 22 115 320 2260 42 1284 31 4888

Trends in New Zealand fur seals on Kangaroo Island

Table 6. Mass (kg) and standard deviation of New Zealand fur seal pups at Cape Gantheaume colony, Kangaroo Island on 27 January 2012, and the long-term data (means for each sex, and maxima and minima of the means for each sex).

2012 Long-term data Male Female Male Female

Mean 6.72 6.40 7.63 6.85

Standard deviation 1.17 1.19 - -

Sample size 55 56 - -

Maximum 8.7 9.5 8.60 7.48

Minimum 3.7 4.3 6.39 5.83

Trends in New Zealand fur seals on Kangaroo Island

Figure 1. Location of the study sites within Cape Gantheaume Wilderness Protection Area on Kangaroo Island. Main sector boundaries used in the mark-recapture procedures at Cape Gantheaume and Berris Point New Zealand fur seal colonies. 21

Trends in New Zealand fur seals on Kangaroo Island

Figure 2. Annual change in New Zealand fur seal pup production at Cape Gantheaume and Berris Point monitored each January between 1989 and 2012.