Action Plan for Seabird Conservation in New Zealand Part B: Non-Threatened Seabirds THREATENED SPECIES OCCASIONAL PUBLICATION NO. 17 Action Plan for Seabird Conservation in New Zealand Part B: Non-Threatened Seabirds THREATENED SPECIES OCCASIONAL PUBLICATION NO. 17 by Graeme A. Taylor Published by Biodiversity Recovery Unit Department of Conservation PO Box 10-420 Wellington New Zealand Illustrations Front cover: Northern diving petrel, North Brothers Island, 1998 Inside front cover: Brown skua, Campbell Island, 1986 Source of illustrations All photographs were taken by the author unless stated otherwise. © May 2000, Department of Conservation ISSN 1170-3709 ISBN 0-478-21925-3 Cataloguing in Publication Taylor, Graeme A. Action plan for seabird conservation in New Zealand. Part B, Non-threatened seabirds / by Graeme A. Taylor. Wellington, N.Z. : Dept. of Conservation, Biodiversity Recovery Unit, 2000. 1. v. ; 30 cm. (Threatened Species occasional publication, 1170-3709 ; 17.) Cataloguing-in-Publication data. - Includes bibliographical references. ISBN 0478219253 1. Sea birds— New Zealand. 2. Rare birds—New Zealand. I. New Zealand. Biodiversity Recovery Unit. II. Title. Series: Threatened species occasional publication ; 17. 236 CONTENTS PART A: THREATENED SEABIRDS Abbreviations used in Parts A and B 7 Abstract 9 1 Purpose 11 2 Scope and limitations 12 3 Sources of information 12 4 General introduction to seabirds 13 4.1 Characteristics of seabirds 14 4.2 Ecology of seabirds 14 4.3 Life history traits of seabirds 15 5 New Zealand seabirds in a global context 16 6 Legal status of seabirds and their habitat (marine and terrestrial) 18 7 Ngai Tahu special relationship with seabirds 19 8 Threats to seabirds 20 8.1 Introduced mammals 20 8.2 Avian predators – weka 21 8.3 Disease 21 8.4 Fire 22 8.5 Weeds 22 8.6 Loss of nesting habitat 23 8.7 Competition for nest sites 23 8.8 Coastal development 24 8.9 Human disturbance 24 8.10 Commercial and cultural harvesting 25 8.11 Volcanic eruptions 26 8.12 Fisheries interactions 26 8.13 Pollution 29 8.14 Plastics/marine debris 29 8.15 Oil spills/oil explorations 29 8.16 Heavy metals/chemical contaminants 30 8.17 Global sea temperature changes 31 8.18 Marine biotoxins 31 237 9 Conservation status of New Zealand seabirds 32 10 Conservation actions required for each threatened seabird taxon 35 10.1 Overview of proposed conservation actions 35 11 Threatened seabird taxa profiles 38 12 References (Part A) 212 Index (Part A) 232 PART B: NON-THREATENED SEABIRDS 13 Introduction to Part B 239 14 Conservation actions required for each non-threatened seabird taxon 242 15 Non-threatened seabird taxa profiles 243 16 Seabird research and management in New Zealand 384 17 References (Part B) 385 APPENDICES FOR PARTS A AND B 1. IUCN Red List categories and criteria at a glance 399 2. Information systems 401 3. Key breeding sites for seabird species in New Zealand 403 4. Seabird census, monitoring, research and management techniques 406 5. Current seabird research and management in New Zealand 418 6. Formal names of plant and animal species (other than seabirds) referred to in the text 432 Index (Part B) 434 238 13. Introduction to Part B Part A of Action Plan for Seabird Conservation in New Zealand dealt with the conservation needs of threatened seabird taxa. Part B covers those taxa that are not listed as threatened using IUCN criteria (see Appendix 1). The seabird taxa in Part B are arranged in alphabetical order on their scientific names. An index of scientific and common names is provided at the back of this document to help locate the text about each seabird taxon. These remaining seabird taxa fit into four distinct groups. The first group (Table 7) includes seabird taxa that are at lower risk of extinction than threatened species but are close to falling into the IUCN Vulnerable category. These taxa are listed as Near Threatened by IUCN criteria. Examples include seabirds which may be declining in part of their range but are stable or increasing elsewhere, or where threatening processes are pushing population size and distribution closer to meeting the criteria listed in Appendix 1. The second group (Table 8) are those taxa considered locally threatened using Molloy & Davis (1992) criteria, i.e. they have small population sizes or a restricted breeding range in New Zealand. These taxa are at risk of disappearing from New Zealand but have large secure breeding populations elsewhere in the world. The third group (Table 9) includes taxa that are culturally significant to one or more iwi. While most seabird species are important to iwi (including the species already discussed in Part A), the two species in Table 9 have a long tradition of being used by iwi for harvest of chicks. These are the only species of seabirds currently available for this purpose under the Wildlife Act 1953. Neither species is considered threatened by IUCN criteria. The fourth group (Table 10) includes all remaining taxa listed as Least Concern by IUCN criteria. These are seabird taxa that have large population sizes, widespread breeding distributions, and no evidence of recent declines. Some of these seabirds may have local populations at risk, especially mainland breeding populations, but in general there is little risk of extinction in the foreseeable future. Note: taxa with equal IUCN and Molloy & Davis rankings are listed in taxonomic order. 239 TABLE 7. LIST OF ‘NEAR THREATENED’ SEABIRD TAXA SPECIES COMMON NAME IUCN RANK MOLLOY & DAVIS RANK Macronectes halli Northern giant petrel Near Threatened Category C Sterna caspia Caspian tern Near Threatened Category O Thalassarche melanophrys Black-browed albatross Near Threatened not listed Puffinus carneipes Flesh-footed Near Threatened not listed shearwater Eudyptula minor iredalei Northern blue penguin Near Threatened not listed Eudyptula minor Cook Strait blue Near Threatened not listed variabilis penguin Eudyptula minor minor Southern blue penguin Near Threatened not listed Eudyptula minor Chatham Island Near Threatened not listed chathamensis blue penguin TABLE 8. LIST OF ‘LOCALLY THREATENED’ SEABIRD TAXA SPECIES COMMON NAME IUCN RANK MOLLOY & DAVIS RANK Pelecanoides georgicus South Georgian Least Concern Category B diving petrel Anous stolidus pileatus Brown noddy Least Concern Category O Gygis alba candida White tern Least Concern Category O TABLE 9. LIST OF CULTURALLY IMPORTANT SEABIRD SPECIES (NOT THREATENED UNDER IUCN CRITERIA) SPECIES COMMON NAME IUCN RANK MOLLOY & DAVIS RANK Puffinus griseus Sooty shearwater Least Concern not listed Pterodroma macroptera Grey-faced petrel Least Concern not listed gouldi 240 TABLE 10. LIST OF NON-THREATENED SEABIRD TAXA (LEAST CONCERN) SPECIES COMMON NAME IUCN RANK MOLLOY & DAVIS RANK Puffinus pacificus Wedge-tailed Least Concern not listed shearwater Puffinus gavia Fluttering shearwater Least Concern not listed Puffinus assimilis elegans Subantarctic little Least Concern not listed shearwater Pelecanoides u. urinatrix Northern diving petrel Least Concern not listed Pelecanoides urinatrix Southern diving petrel Least Concern not listed chathamensis Pelecanoides urinatrix Subantarctic diving Least Concern not listed exsul petrel Daption capense australe Snares Cape pigeon Least Concern not listed Pachyptila turtur Fairy prion Least Concern not listed Pachyptila desolata banksi Antarctic prion Least Concern not listed Pachyptila vittata Broad-billed prion Least Concern not listed Pterodroma nigripennis Black-winged petrel Least Concern not listed Pterodroma n. neglecta Kermadec petrel Least Concern not listed Pterodroma lessonii White-headed petrel Least Concern not listed Pterodroma m. mollis Soft-plumaged petrel Least Concern not listed Pterodroma inexpectata Mottled petrel Least Concern not listed Oceanites nereis Grey-backed storm Least Concern not listed petrel Pelagodroma marina New Zealand white- Least Concern not listed maoriana faced storm petrel Fregetta t. tropica Black-bellied storm Least Concern not listed petrel Phaethon rubricauda Red-tailed tropicbird Least Concern not listed roseotincta Morus serrator Australasian gannet Least Concern not listed Phalacrocorax carbo Black shag Least Concern not listed novaehollandiae Phalacrocorax sulcirostris Little black shag Least Concern not listed Phalacrocorax Little shag Least Concern not listed melanoleucos brevirostris Stictocarbo p. punctatus Spotted shag Least Concern not listed Stictocarbo punctatus Blue shag Least Concern not listed steadi Catharacta antarctica Brown skua Least Concern not listed lonnbergi Larus d. dominicanus Southern black-backed Least Concern not listed gull Larus scopulinus Red-billed gull Least Concern not listed Anous minutus minutus Black noddy Least Concern not listed Procelsterna a. albivitta Grey ternlet Least Concern not listed 241 14. Conservation actions required for each non-threatened seabird taxon This section provides a detailed account of priority conservation actions that are needed for each of the 43 non-threatened seabird taxa breeding in New Zealand. The conservation status, distribution, population size, known and potential threats, and past conservation actions are summarised for each taxon. The future management actions, survey and monitoring needs, and research needs are prioritised for each taxon into categories H, M, and L as described below. Actions and needs within each category are further prioritised, e.g. H1 and H2. High (H) This category includes actions that protect seabird taxa from the risk of local extinction or help to