Puffinus Griseus Research Articles

The Breeding of the Sooty Shearwater on Courts Island, Tasmania, and Montagu Island, N.S.W.

The Breeding of the Sooty Shearwater on Courts Island, Tasmania, and Montagu Island, N.S.W.

NOTES ON THE MOTTLED PETREL PTERODROMA INEXPECTATA AND OTHER PETRELS

SummaryField work by the author on petrels began in 1936 and finished in 1957, many of the results of which have already been published. The Mottled Petrel was not studied in detail, as were the other species concerned, and this paper brings together those observations which were made on the Mottled Petrel and compares them with the other species studied. In the main the timing of the breeding season and the breeding behaviour of the Mottled Petrel appear to be much the same as for the Sooty Shearwater.

THE PELAGIC DISTRIBUTION OF THE SOOTY SHEARWATERPROCELLARIA GRISEA

Summary.The breeding distribution of the Sooty Shearwater and the dates of its breeding season are briefly reviewed.Records from the Southern Ocean are summarised. It is concluded that they are accounted for by non‐breeding birds feeding off the ice‐edge in the Australian sector of the Antarctic during the latter part of the breeding season.The great majority of Sooty Shearwaters spend the southern winter in the Pacific Ocean. Birds from the New Zealand colonies are probably mostly found on the feeding grounds off Japan: some may make a “circular” migration around the Pacific. Birds from the Cape Horn colonies spend the southern winter in the rich areas off the western coast of North America.Some Sooty Shearwaters spend the southern winter off the South African coasts. A number of non‐breeding birds remain there throughout the summer.The Sooty Shearwaters “wintering” in the North Atlantic are probably numbered in tens of thousands only. The distribution of records is reviewed month by month and the records from Atlantic transects are summarised. The migrations in the North Atlantic are discussed in relation to prevailing meteorological and oceanographic conditions, and food supply. It is concluded that most Sooty Shearwaters in the North Atlantic make a “circular” migration, crossing the North Atlantic from west to east in June and July, and re‐crossing about September further south in the northeast trades.

BIOLOGY OF THE SOOTY SHEARWATER PUFFINUS GRISEUS

On a small half‐acre island at the southern end of New Zealand a study was made of a complete community of Sooty Shearwaters from the end of 1940 to the beginning of 1957. In the season 1953–54, when the greatest emphasis was put on an estimate of the population, 551 marked birds were known to have been alive. This indicated a population of around 600 adult birds. Up to the end of January or a little later, unemployed birds constituted some two‐thirds of the community. There were about 300 burrows available each year, but in about one‐third no bird was found.Three biological points stand out above all others. The first is the periodic nestling mortality, which suggests one chick is all the parents can rear even if things go well, which does not always happen. The second is the tight fit of the breeding season, with pressure to migrate near the end of it. This probably means the parents find it hard to food themselves, lot alone a chick, in the last stages, as otherwise the migratory urge would not develop so early. The third is the low annual mortality, which may be as little as 6 per cent. If so, the average expectation of further life would be around 16 years.

Sixth annual report of the Australian Bird-Banding Scheme, July 1959 to June 1960

During 1959-60, 34,996 birds of 238 species were banded, and there were 6813 recoveries of 122 species, including 3539 individuals not previously recovered. Although the total number banded this year was 2000 below last year's total, there was an increase of nearly 3000 in the number of free-flying birds banded, a result fbr which mist-netting was largely responsible. Since 1953, 138,672 birds of 298 species have been banded, and 14,296 (10.3%) have been recovered 24,618 times (17.7%). The silver gull, Larus novae-hol2andiae Stephens, accounted for 10,737 of the birds banded. Full data for 65 selected recoveries are given. This year was notable for the first recoveries from Papua-New Guinea: a white ibis, Threskiornis molucca (Cuvier), banded in Victoria, and a little egret, Egretta garzetta (L.), banded in New South Wales; other striking recoveries were a sooty shearwater, Pufinus griseus (Gmelin), which migrated from Lion Island, New South Wales, to Japan, and a starling, Sturnus vulgaris L., banded in Tasmania, and recovered 29 days later at Brisbane.

First Specimens of Sooty Shearwater for Delaware

First Specimens of Sooty Shearwater for Delaware

Another Victorian Specimen of the Sooty Shearwater

Another Victorian Specimen of the Sooty Shearwater

DURATION OF PARENTAL ATTENTIVENESS IN THE SOOTY SHEARWATER.

SUMMARYParental attentiveness in. the Sooty Shearwater Puffinus griseus was studied on Whero Island, near Stewart Island, New Zealand, in 1951‐52 and 1952‐53. In the first year 30 chicks were watched from 18 March until they left the burrow, and in the second year 57 chicks from 10 February (i.e. for practically the whole of the chick stage).The chief feature of the pre‐desertion period is the irregularity of parental attention (with wide individual variation). Inattentive periods range from 1 to 25 days (mean 4‐3), attentive from 1 to 11 days (mean 2–4).From 10 February to 31 March 1953, 13%‐65% (mean 37‐2%) of the chicks were visited nightly by parents; from 1 April to 18 April, 13%˜46% (mean 27'5%); and from 19 April to 4 May, 0 %–11 % (mean 3%). In the second period 43 chicks (76‐8%) were deserted by their parents, and in the third period all the remaining 13 chicks.Of 83 chicks which survived to leave the burrow in the 1951‐52 and 1952‐53 seasons, 58 (70%) left weighing more than 455 grams and 25 (30%) weighing less. Only the former group of chicks was believed to survive.Parents desert the breeding area in any given season apparently in answer to a migration urge, irrespective of the chick's age. Chicks hatched late therefore have little chance of survival.The length of time a chick remains in the burrow varies from 86 to 106 days (mean 97). The chicks leave the burrow apparently in answer to an internal urge, irrespective of the degree of parental attention.Before finally leaving the burrows, chicks may emerge at night and then return. Chicks more than 455 grams at departure emerged from 0 to 14 nights (mean 5–9 nights).The length of the desertion period is much shorter than we have been led to believe. For 58 normal chicks the period ranged from 0 to 27 days (mean 12 days). Chicks have been known to be fed just before departure and birds assumed to be parents have been known to enter the burrow after the chick has departed. If so, this means that these chicks departed in an inattentive period by the parent.The presence or otherwise of a desertion period in petrels depends on whether or not the species concerned is migratory. For example, as far as is known, migratory shearwaters have a short desertion period, but the non‐migratory Royal Albatross and other species have not.

The Sooty Shearwater in Australia

The Sooty Shearwater in Australia

Sooty Shearwater in Tasmania

Sooty Shearwater in Tasmania

Migration of the Sooty Shearwater off the Washington Coast

Migration of the Sooty Shearwater off the Washington Coast

The Sooty Shearwater in New Zealand

The Sooty Shearwater in New Zealand

Sooty Shearwater and Audubon's Shearwater in North Carolina

Sooty Shearwater and Audubon's Shearwater in North Carolina

The Sooty Tern and Audubon's Shearwater in South Carolina

The Sooty Tern and Audubon's Shearwater in South Carolina