Antarctic Petrel Thalassoica Antarctica Research Articles

Sex determination of Antarctic Petrels Thalassoica antarctica by discriminant analysis of morphometric characters

We present data on sexual dimorphism in some morphological measurements (wing length, head length, bill depth and bill length) in the Antarctic Petrel Thalassoica antarctica. Males were on average larger than females for all measurements. Sexual dimorphism was on average largest for bill depths whereas wing lengths discriminated least between the sexes. A discriminant function including bill depth, head length and wing length correctly sexed 92% of the sample. Due to between-measurer variation it is recommended that morphometric measurements obtained by others on sexed birds are compared with ours before proceeding with the use of the discriminant function on unsexed individuals.

A further contribution on the biology of the Antarctic flea, Glaciopsyllus antarcticus (Siphonaptera: Ceratophyllidae)

Experiments showed that adult Antarctic Fleas Gladopsyllus antarcticus preferred dark over light conditions, dry over wet conditions, and fine substrate over coarse substrate. Examination of seabird chicks and collections of nest material indicated that the Southern Fulmar Fulmarus glacialoides, is the major host species of the Antarctic Flea, while Snow Petrels Pagodroma nivea, Cape Petrels Daption capense, Antarctic Petrels Thalassoica antarctica, and Wilson's Storm-Petrels Oceanites oceanicus are minor hosts. This is the first report of Antarctic Fleas occuring on either Antarctic Petrels or Wilson's Storm-Petrels. No fleas were found associated with Southern Giant Petrels Macronectes giganteus, Antarctic Skuas Catharacta maccormicki, or Adelie Penguins Pygoscelis adeliae. No live fleas were found in Southern Fulmar nest material during their period of dispersal over the winter months, supporting the hypothesis that Antarctic Fleas survive the winter period by remaining on their seabird host.

The stomach contents of Antarctic petrels Thalassoica antarctica feeding young chicks at Scullin Monolith, Mawson Coast, Antarctica

Antarctic petrels (Thalassoica antarctica) brooding young chicks at Scullin Monolith (67°7′S, 66°42′E), Antarctica, fed fish and crustaceans (87% and 13%, respectively, on a mass basis) to their young. Amounts of solids fed were equivalent to 6.6% of the body mass of adult birds with an empty stomach. The prey comprised species known to occur in the surface layers of the Antarctic ocean in the east wind drift, such as Pleuragramma antarcticum, Notolepis coatsi and Euphausia superba, consistent with the surface feeding habits of Antarctic petrels.

Census of breeding Antarctic Petrels Thalassoica antarctica and physical features of the breeding colony at Svarthamaren, Dronning Maud Land, with notes on breeding Snow Petrels Pagodroma nivea and South Polar Skuas Catharacta maccormicki

Only about a dozen breeding colonies of the Antarctic Petrel Thalassoica antarctica are known, all confined to the Antarctic continent. In 1985 one of the largest colonies, situated in Muhlig-Hofmannfjella, Dronning Maud Land, c. 200 km from the open sea and at an elevation of 1600 m a.s.l. was censused around the time of hatching. The colony size was estimated at about 207,000 breeding pairs. Three minor colonies were discovered at Jutulsessen, Gjelsvikfjella.Microclimatic measurements were made to evaluate the physical environment experienced by the breeding petrels and their chicks in the hostile Antarctic climate. The temperatures measured and energy budget made for the hillside, where the colony was located, showed that the nests of the Antarctic Petrel are placed at relatively favourable places. The northeast facing slope with the Antarctic Petrel colony absorbed large quantities of shortwave radiation during the birds’breeding season and provided suitable microclimatic conditions for breeding.

Census of breeding Antarctic petrels Thalassoica antarctica and physical features of the breeding colony at Svarthamaren, Dronning Maud Land, with notes on breeding snow petrels Pagodroma nivea and south polar skuas Catharacta maccormicki

Only about a dozen breeding colonies of the Antarctic Petrel Thalassoica antarctica are known, all confined to the Antarctic continent. In 1985 one of the largest colonies, situated in Muhlig-Hofmannfjella, Dronning Maud Land, c. 200 km from the open sea and at an elevation of 1600 m a.s.l. was censused around the time of hatching. The colony size was estimated at about 207,000 breeding pairs. Three minor colonies were discovered at Jutulsessen, Gjelsvikfjella.Microclimatic measurements were made to evaluate the physical environment experienced by the breeding petrels and their chicks in the hostile Antarctic climate. The temperatures measured and energy budget made for the hillside, where the colony was located, showed that the nests of the Antarctic Petrel are placed at relatively favourable places. The northeast facing slope with the Antarctic Petrel colony absorbed large quantities of shortwave radiation during the birds’breeding season and provided suitable microclimatic conditions for breeding.

Interrelationships between egg dimensions, pore numbers, incubation time, and adult body mass in Procellariiformes with special reference to the Antarctic Petrel Thalassoica antarctica

Interrelationships between egg dimensions, pore numbers, incubation time, and adult body mass in Procellariiformes with special reference to the Antarctic Petrel Thalassoica antarctica

Interrelationships between egg dimensions, pore numbers, incubation time, and adult body mass in Procellariiformes with special reference to the Antarctic petrel Thalassoica antarctica

Dimensions of eggs and eggshells and pore density are reported for eggs of the Antarctic Petrel Thalassoica Antarctica (as well as eggs of the Snow Petrel Pagodroma nivea). Allometric relationships are used to estimate the initial egg mass, total number of pores and incubation time. The initial egg mass for Antarctic Petrel was estimated to 83 g, and the incubation time to 55 days. The total pore number in Antarctic Petrel was estimated to 4212 and in Snow Petrel 2654 pores per egg. Using data from 8 species of Procellariiformes, the relationship between total pore counts, initial egg mass and incubation time is described.

Behaviour of Antarctic Petrels and Antarctic Fulmars Before Laying

Antarctic Petrels Thalassoica antarctica and Antractic Fulmars Fulmarus glacialoides nest in adjoining areas on Odbert and Ardery Islands, Wilkes Land, Antarctica. Observation of their arrival, nesting location, courtship displays and copulation revealed similarities but also some marked differences between the species. Antarctic Petrels deserted the nesting area before laying, whereas Antarctic Fulmars probably remained at their nests. The full sequence of arrival, courtship and copulation was much more compressed in the Antarctic Petrels than in the Fulmars. Courtship and copulation are described and discussed.