NOTORNIS Journal of the Ornitho1ogic:al Society of New Zealand Volume 26 Part 3 September 1979 OFFICERS 1978 - 79 President - Mr. B. D. BELL, Wildlife Service, Dept. of Internal Affairs, Private Bag, Wellington Vice-president - Mr. M. L. FALCONER, 188 Miromiro Road, Normandale, Lower Hutt Editor -Mr. B. D. HEATHER, 10 Jocelyn Crescent, Silverstream Treasurer - Mr. H. W. M. HOGG, P.O. Box 3011, Dwedin Secretary - Mr. H. A. BEST, Wildlife Service, Dept. of Internal Affairs, Wellington Council Members: Dr. BEN D. BELL, 45 Gurney Road, Belrnont, Lower Hutt Mrs. B. BROWN, 39 Red Hill Road, Papakura Dr. P. C. BULL, 131 Waterloo Road, Lower Hutt Mr D. E. CROCKETT, 21 McMillan Avenue, Kamo, Whangarei Mr. F. C. KINSKY, 338 The Parade, Island Bay, Wellington 5 Mrs. S. M. REED, 4 Mamaku Street, Auckland 5 Mr. R. R. SUTTON, Lorneville, No. 4 R.D., Invercargill Conveners and Organisers: Rare Birds Committee (Acting) : Mr. B. D. BELL Beach Patrol: Mr. C. R. VEITCH, Wildlife Service, Dept. of Internal Affairs, P.O. Box 2220, AucMand Card Committee: Mr. R. N. THOMAS, 25 Ravenswood Drive, Forest Hill, Auckland 10 Field Investigation Commiftee: Mr. B. D. BELL Librarian: Miss A. J. GOODWIN, R.D. 1, Clevedon Nest Records: Mr. D. E. CROCKETT Recording (including material for Classified Summarised Notes) : Mr. R. B. SIBSON, 26 Entrican Avenue, Remuera, Auckland Representative on Member Bodies' Committee of Royal Society of N.Z.: Mr. B. D. BELL Assistant Editor: Mr A. BLACKBURN, 10 Score Road, Gisborne Editor of OSNZ News: Mr P. SAGAR, 38A Yardley St., Christchurch 4 SUBSCRIPTIONS AND MEMBERSHIP Annual Subscription: Ordinary member $12; Husband & wife mem- bers $18; Junior member (under 20) $9; Life member $240; Family member (one Notornis per household) bein other family of a member in the same household as a member g6; institution $20; Overseas member $2.00 extra. Subscriptions are for the calendar year of first joining and are renewed by invoice each January. Please pay promptly to ensure receiving Notornis and OSNZ News. Applications for membership, changes of address and resignations should be sent to the Treasurer. Exchanges and library subscriptions should be sent to the Treasurer. Editorial matters ONLY should be sent to the Eritor. [Registered with the GPO Gisborne as a publication] ISSN 0029 .4470 CONTENTS WILLIAMS. MURRAY The Social Structure. Breedin and Population Dynamics of Paradise Shelduck in the ~istorne- East Coast District ............ ...... ...... ...... ...... 213 POWLESLAND. R . G . Pellet Casting by South Island Robins ...... 273 BEST. H . A . Observations on Habitat Selection hy South Island Fernbirds ...... ...... ...... ...... ...... ...... ...... 279 VEITCH. C . R . Kaipara Harbour - Easter 1978 ............ 289 Annual General Meeting Reports ............ ................. 297 Short Notes TUNNICLIFFE. G . A . Homing Behaviour in the Yelloweyed Penguin ...... ...... .................. ...... ...... 287 BROWN. B . LAWRIE. D . A . Masked (Blue-faced) Boobies in the Firth. of Thames ........................ ............ 304 WILLIAMS. M . Detecting the presence of Blue Duck from its Faecal Sign ...... ...... .................. ...... ...... 306 BERRUTI. A . The PIumages of Fledgling Phoebel'ria Albatrosses 308 CROUCHLEY. G . 8t D . Multiple Clutches by Welcome Swallows in the Wairarapa ....................... ............ 309 COCKREM. J . F . Starlings Bathing in Flocks ...... ...... ...... 312 BROWN. 3. Pre-migration Display by Mongolian Dotterel to Banded Dotterels ........................ ............ 312 BAWLOW. M . Antarctic Petrels around Foveaux Strait ...... ...... 313 JOHNSTON. A . Further Sighting of the White: Form of the Southern Giant Petrel ...... ............ ............ 314 MORRISON. K . Bird Observations on North Meyer Islet ..... 317 HATCH; J . H . Brood Size of the N.1. Kokako ...... ............ 318 DENNISON. M . D . Sharp-tailed Sandpiper Displays ............ 319 PLATES by M . F . Soper Aucklancl Islands Banded Dotterel on Enderby Island ...... 311 Wandering Tattler in non-breeding Plumage at Rarotonga in July .................. ...... 315 Grey-tailed Tattler ii"non:bieeding plumage at Norfolk Island in july .................. ...... ...... 316 THOMAS. R . N . White-tailed Tropic Birds on North Auckland West Coast Beaches ............ ............ ...... ...... 320 GORDON. AUDREY White-tailed Tropic Birds on North Auckland West Caost Beaches ...... ...... ...... ...... 320 Letters R . B. SIBSON .............................. ...... ...... 321 JOHN M . CLARK .............................. ...... ...... 321 R . B . LAVERS ...... ............ ".... ...... ...... ...... 322 Reviews R . J . SCARLETT The Dromornithidae (Rich) ............ ...... 322 .R. J . SCARLETT Hind Limb Musculature of the Brown Kiwi (McGowan) ...... .................................... 323 Notice to Authors ............................. ...... ...... 324 Printed by TE RAU PRESS LTD., Peel Street. Gisborne REGIONAL REPRESENTATIVES FAR NORTH: D. E. Crockett, 21 McMillan Ave., Kamo, Whangarei. NORTHLAND: { Ph. 50954. AUCKLAND: Mrs S. Reed, 4 Mamaku St., Auckland 5. Ph. 547784. SOUTH AUCKLAND: Mrs Beth Brown, 39 Red Hill Rd., Papakura. Ph. 2988157. WAIKATO: Mrs B. Seddon, 11 Grey Street, Cambridge. Ph. 7761. BAY OF PLENTY: R. M. Weston, 250 River Road, Kawerau. Ph. 8357. VOLCANIC PLATEAU: R. W. Jackson, 9 Kenrick Road, Rotorua. Ph. 86907. GISBORNE/WAIROA: J. C. Henley, 9 Mason St., Gisborne. Ph. 85181. TARANAKI: R. E. Lambert, Taranaki.Museum,.Box.315,.New Plymouth. MANAWATU: Dr L. J. Davies, DSIR, Private Bag, Palmerston North. Ph. 87680. HAWKES BAY: N. B. Mackenzie, Wildlife Trust, Main Road, Westshore, Napier. Ph. 59451. WAIRARAPA: D. Sim, Lake Ferry, R.D. 2, Featherston. Ph. 828 Pirinoa. WANGANUI: L. C. Edlin, 5 Poutini St., Wanganui East. Phone 32452. WELLINGTON: A. H. Gollop, 6 Dawn Grove, Akatarawa, Upper Hutt. Phone 268749. NELSON: Mrs J. Hawkins, 772 Atawhai Drive, Nelson. Ph. 520151. MARLBOROUGH: Mrs P. Jenkins, 30 Maxwell Road, Blenheim. , Phone 83775. CANTERBURY: P. M. Sagar, 38A Yardley Street, Christchurch 4. WEST COAST: C. S. Lauder, 9 Winnie Street, Greymouth. Ph. 6349. OTAGO: M. R. R. Foord, 39 Park St., Dunedin North. Phone. 776213. SOUTHLAND: R. R. Sutton, Lorneville, No. 4 R.D., Invercargill. Ph. 358230. LITERATURE AVAILABLE From all bookshops: A field guide to the birds of New Zealand, by R. A. Falla, R. B. Sibson and E. G. Turbott, new ed. $13.95 From B. D. Heather, 10 Jocelyn Crescent, Silverstream: A biology of birds, by B. D. Heather. $1.50 From Mrs H. Hagen, 53 Minnehaha Street, Tifirangi, Auckland 7: Back numbers of ' Notornis ': Parts of Vol. 1, 50c each; Vols. 2-13,$1.00 per part; Vols. 14-21,$1.50 per part; Vols. 22-, $2.00 per part; all plus 10% postage. Reports and bulletins (1939-1942) $2.00 OSNZ Library catalogue (1976 ed) 17 pp. $0.55 Banding reports, Nos 8-14,55c each. Kelmadec Expedition, 1964, by A. T. Edgar. $0.50 Guide to Identification of Shearwaters and Petrels in New Zealand waters (Auckland Museum), J. P. Croxall $0.55 From P. C. Harper, Dept of Extension Studies, University of Canterbury, Chrisfchurch: Southern albatrosses and petrels: an identification guide, by P. C. Harper & F. C. Kinsky, 1978 edition $5 .OO From P.O. Box 1239, Wellington North: Bird distribution in N.Z. A provisional atlas. $6.00 From B. D. Bell, 9 Ferry Road, Seatoun, Wellington: OSNZ tie (mid-grey with Notomis motifs). $6.00 NOTORNIS is the journal of the Ornithological Society of New Zealand (Inc.) Editor: B. D. Heather, 10 Jocelyn Crescent, SILVERSTREAM VOLUME 26 PART 3 SEPTEMBER, 1979 THE SOCIAL STRUCTURE, BREEDiNG AND POPULATION DYNAMICS OF PARADISE SHELDUCK 1N THE GISBORNE-EAST COAST DISTRICT By MURRAY WILLIAMS ABSTRACT The breeding biology of the Paradise Shelduck (Tadorna variegata) was studied on hill-country farmland west of Toko- maru Bay, New Zealand, during 1973-1976. Throughout the breeding season the shelduck population comprised territorial pairs, which occupied areas of pasture surrounding stock ponds or other water bodies, and flocks, which were mostly of juveniles and which remained at specific sites on river terraces or hillsides. Breeding was attempted only by the territorial pairs. Prospecting for nest sites started in late June and 62% of 47 nests found were in hollow logs on the ground'. Laying began in August and the mean size of 36 clutches was 9.4. Of 282 eggs, 5% were infertile and 87% of the fertile eggs hatched. Only 20% of the pairs which lost their clutches re-nesited. Ducklings were reared on stock ponds, in streams or rivers, and in swampy soaks on hillsides. About 60% of the ducklings reaching the rearing areas survived the 8-week fledging period. The main causes of duckling mortality were bad weather and predation by feral cats. During their first week, ducklings fed mostly on aquatic insects, and thereafter on plant material. Of 67-7 ducklings which fledged, 54.7% were males, and, after fledg- ing, males dispersed more widely than females . 21 4 WILLIAMS NOTORNIS 26 Ten (13%) of the 78 territorial pairs studied during 1973- 1975 did not attempt to breed, 46 (59%) appeared with duck- lings, and the nesting attempt of 22 (28%) failed. Each pair of territorial shelducks which attempted breeding produced 2.6-2.8 ducklings annually. The mean percentage annual survival of territorial shelducks was 64%, while about 50?b of the flock birds survived their first year and 55% their second. In most cases, birds first attempted to breed when two years old. The number of flock birds doubled each