Light-bellied Brent Goose Branta bernicla hrota (East Atlantic population) in Svalbard, Greenland, Franz Josef Land, Norway, Denmark, the Netherlands and Britain 1960/61 – 2000/01 Matthew JH Denny1, Preben Clausen2, Stephen M Percival3, Guy QA Anderson4, Kees Koffijberg5 & James A Robinson6 1 Vine Cottage, Middletown, Hailey, Witney, Oxon OX29 9UB, UK 2 National Environmental Research Institute, Kalø, Grenåvej 12, DK-8410, Rønde, Denmark 3 Ecology Consulting, 71 Park Avenue, Coxhoe, Durham DH6 4JJ, UK 4 Royal Society for the Protection of Birds, The Lodge, Sandy, Beds SG19 2DL, UK 5 SOVON, Rijksstraatweg 178, NL-6573 DG Beek-Ubbergen, The Netherlands 6 The Wildfowl & Wetlands Trust, Slimbridge, Glos GL2 7BT, UK Waterbird Review Series © The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee All rights reserved. Apart from any fair dealing for the purpose of private study, research, criticism or review (as permitted under the Copyright Designs and Patents Act 1988), no part of this publication may be reproduced, sorted in a retrieval system or transmitted in any form or by any means, electronic, electrical, chemical, optical, photocopying, recording or otherwise, without prior permission of the copyright holder. ISBN 0 900806 48 6 This publication should be cited as: Denny, MJH, P Clausen, SM Percival, GQA Anderson, K Koffijberg & JA Robinson. 2004. Light-bellied Brent Goose Branta bernicla hrota (East Atlantic population) in Svalbard, Greenland, Franz Josef Land, Norway, Denmark, the Netherlands and Britain 1960/61 – 2000/01. Waterbird Review Series, The Wildfowl & Wetlands Trust/Joint Nature Conservation Committee, Slimbridge. Published by: The Wildfowl & Wetlands Trust Joint Nature Conservation Committee Slimbridge Monkstone House Gloucestershire City Road GL2 7BT Peterborough PE1 1JY T: 01453 891900 T: 01733 562626 F: 01453 890827 F: 01733 555948 E: [email protected] E: [email protected] Design and typeset by Jim Broughton and Paul Marshall Cover design by Pyneapple Printed by Crowes Complete Print, 50 Hurricane Way, Airport Industrial Estate, Norwich, Norfolk NR6 6JB Front cover: Light-bellied Brent Geese by Dick Newell Back cover: Lindisfarne NNR (England) by Peter Wakely/English Nature ii CONTENTS Summary iv 1 The East Atlantic Light-bellied Brent Goose 1 1.1 Introduction 1 1.2 Background 1 1.3 Monitoring and population assessment 3 1.3.1 Counts 3 1.3.2 Productivity 3 1.3.3 Ringing 3 1.3.4 Population assessment 4 1.4 Annual cycle 5 1.4.1 Breeding season 5 1.4.2 Autumn migration 7 1.4.3 Winter distribution 7 1.4.4 Spring staging and migration 8 1.5 Conservation and management 9 1.5.1 Legislation and other conservation measures 9 1.5.2 Hunting 12 1.5.3 Agricultural conflict 12 2 Survey of areas used during the non-breeding season 13 2.1 Britain 14 2.1.1 England 14 2.1.2 Scotland 19 2.2 Denmark 20 2.3 The Netherlands 32 3 Survey of areas used during the breeding season 34 3.1 Svalbard 36 3.2 Greenland 38 3.3 Franz Josef Land 39 4 Future research needs 40 5 Acknowledgements 41 6 References 42 iii SUMMARY This review aims to assess the changes in status, the use of the previous main autumn staging area in abundance and distribution of the Svalbard/North the Danish Wadden Sea. By mid to late winter, most Greenland population of Light-bellied Brent Geese birds have moved from the wintering sites to spring Branta bernicla hrota throughout its range, focusing staging areas at Nissum Fjord, and increasingly at primarily on its winter range in England and Agerø and several other sites, in Denmark. In spring, Denmark since winter 1960/61, to collate gathered what appears to be the whole population is found in information prior to that winter, to review published Denmark. Evidence suggests that many Light-bellied and unpublished data on the ecology of this goose Brent Geese stage at non-breeding sites in Svalbard population, and to describe numbers, trends and site before moving to the breeding areas. use at the key resorts in the non-breeding range and during other periods of the annual cycle. In this The majority of the population breeds in Svalbard. review, this biogeographic population is referred to Breeding numbers have declined severely since the as the East Atlantic Light-bellied Brent Goose. beginning of the 20th century, when many birds were believed to nest on the westernmost islands. This population of Light-bellied Brent Geese breeds Today the main colonies are on Tusenøyane, in the in the High Arctic, primarily in Svalbard, east southeast, and Moffen, in the northwest, where Greenland and Franz Josef Land, and winters internationally important numbers nest. Productivity primarily in Denmark and at Lindisfarne, northeast is also highest in these areas. A recently discovered England. The geese stage in Denmark in the spring breeding area in northeast Greenland held 1,100 before embarking on the longest unbroken migration adult birds in 1998. The size of the population on of any Western Palearctic goose population to Franz Josef Land is difficult to gauge because of the breeding grounds farther north than those of any lack of surveys, but is likely to be small and relatively other goose population. Post-breeding and non- unproductive. Sparse data suggest that moulting breeding birds moult in the Arctic, before migrating areas are highly dispersed, with internationally direct to Denmark or England. important numbers found at eight sites in Svalbard and one in Greenland. The moulting grounds of The population size was in the region of 50,000 over half the population, however, remain unknown. individuals before a wasting disease in Zostera marina, a principal food, and/or human over-exploitation Traditionally, Light-bellied Brent Geese used only caused a massive decline in the first half of the 20th what might be regarded as natural habitats, feeding century. The population, then wintering mainly in on intertidal and subtidal seagrass (Zostera spp. and Denmark, decreased to a low of 1,600–2,000 in the Ruppia spp.) and algal (Enteromorpha spp. and Ulva years 1967–71. The population has since grown lactuca) beds and saltmarshes. Since 1991, however, slowly, to over 6,600 by 2001, around half of which birds have started feeding on agricultural land at regularly winters in Britain. many of their winter and spring sites, using autumn- sown cereals, pastures and spring-sown cereal seeds, This population of Light-bellied Brent Goose has a which leads to conflicts with agricultural interests. restricted non-breeding distribution. Recent counts Breeding birds are known to feed on tundra herbs, demonstrate that 11 non-breeding sites are mosses and lichens. internationally important: 10 in Denmark and one in Britain, four of which regularly hold over 50% of the Further basic research into the distribution and population. There is much interchange of individuals ecology of breeding, moulting and migrating birds between these sites. Traditionally, the main wintering should help to fill existing gaps in knowledge that are sites were Mariager & Randers Fjords in Denmark, vital for the effective conservation of this but Lindisfarne has become increasingly important population. Continued monitoring, ringing and with numbers increasing from around 200 ecological studies at the winter and spring staging individuals in the 1950s to 2,500–3,000 in the 1990s. sites will mean that changes in the population can be During the late 1990s, Nibe & Gjøl Bredninger in detected and allow the development of individuals- Denmark was also a key wintering site. Occasionally, based models, a population viability analysis and, during severe weather in Denmark, up to 80% of the ultimately, a flyway management plan. This work population uses Lindisfarne, and flocks scatter to should focus particularly on possible environmental alternative coastal sites around the North Sea, perturbations, such as climate change, that may especially in the Netherlands. adversely affect the conservation status of the population, as well as on direct conflict with human Birds have been arriving at wintering sites activities. increasingly early, with a corresponding decrease in iv East Atlantic Light-bellied Brent Goose 1 THE EAST ATLANTIC LIGHT-BELLIED BRENT GOOSE from the Svalbard Goose Conference papers collated 1.1 Introduction in Norsk Polarinstitutt Skrifter No. 200 (1998). Additional information from other papers and This flyway population of Light-bellied Brent Geese unpublished material is presented here, giving an up- Branta bernicla hrota breeds on Svalbard, Franz Josef to-date account of our knowledge of this goose Land and northeast Greenland (Clausen et al. 1999), population. winters in northwest Europe (Fig. 1) and is known as the ‘Svalbard/North Greenland’ or ‘East Atlantic’ The second section presents site-specific monitoring Light-bellied Brent Goose. In this review it will be data for wintering and spring staging sites, in some referred to either as the ‘East Atlantic Light-bellied cases from as early as winter 1960/61, to at least Brent Goose’ or simply the ‘Light-bellied Brent 1999/2000. Annual maxima are illustrated for Goose’. internationally important sites, i.e. those that regularly support over 1% of the flyway population The first reliable estimate for the size of this (presently 50 individuals; Wetlands International population was published in the early 1950s 2002), and spatial and temporal changes in (Salomonsen 1958). Co-ordinated counts of the abundance and distribution are examined. The use of whole population began in 1980 – but scattered occasional wintering sites is summarised. The third information from the Danish spring staging areas section summarises the known status and from the 1960s and 1970s gives fairly reliable distribution of breeding and moulting birds in the information about the population size in that period Arctic and follows a format similar to the second.