Phoebetria Palpebrata Research Articles

Comparison of gonadal steroids and LH in biennially and annually breealbatrosses at South Georgia

The relative importance of genetic vs. environmental factors in determining the pattern of avian post-embryonic development is much debated. Previous cross-fostering of albatrosses suggested that although inter-specific variation in growth rate was determined primarily by differences in dietary energy content, species-specific constraints might have evolved that could limit maximal growth, even in chicks fed at similar rates and on similar diets. This study aimed to determine whether intrinsic differences in resting metabolic rate were apparent during the linear phase of growth in chicks of three species (black-browed, grey-headed and light-mantled sooty albatrosses). There was a gradual increase in absolute, and a reduction in mass-specific metabolic rate from 5.0 W kg−1 during the earliest part of linear growth, to 3.5 W kg−1 by the time chicks reached peak mass. These values are considerably higher than in resting adults of comparable or lower mass, presumably reflecting the large size and high metabolic demand of organs involved in rapid nutrient processing and tissue synthesis by chicks. The lack of any detectable inter-specific variation in the pattern of metabolic rate changes casts some doubt on the existence of fundamental differences in growth rate that cannot be attributed simply to differences in dietary energy or nutrient delivery rate.

Breeding biology of the Light‐mantled sooty albatross (Phoebetria palpebrata) at South Georgia

Aspects of the breeding biology of the Light‐mantled sooty albatross Phoebetria palpebrata were studied at South Georgia. Its breeding distribution there is summarized and an annual breeding population of c. 5000 breeding pairs estiamted. Laying, hatching and fledgine dates are given, together with egg measurements and data on the duration of incubation and brooding shift. Chick growth in weight and wing length from hatching to fledging was followed in detail.Breeding season adaptations of P. palpebrata are compared with those of the other three albatrosses at South Georgia. The slow chick growth of P. palpebrata results in a nestling period even longer than those of the two larger mollymawks and is attributable mainly to the lower frequency of feeding resulting from the highly pelagic existence of adult P. palpebrata.Comparisons are made with other breeding populations and especially with that on Marion Island. This is basically very similar and differences in chick growth patters are suggested to relate to differences in diet and particulartly to the frequency with which chicks receive food.

The Food and Feeding Ecology of the Light-Mantled Sooty Albatross at South Georgia

SUMMARYTHOMAS, G. 1982. The food and feeding ecology of the Light-mantled Sooty Albatross at South Georgia. Emu 82: 92–100The diet of the Light-mantled Sooty Albatross Phoebetria palpebrata breeding at South Georgia is described on the basis of quantitative analysis of thirty-seven food samples from chicks and nine from adults. Squid and krill Euphausia superba were the main components by weight and by frequency of occurrence, although fish were also taken.Identifiable fish were chiefly myctophids; measurable krill were mature individuals. Of the eleven species of squid recorded, the most important were Mesonychoteuthis sp A (by numbers) and?Discoteuthis sp (by weight). These species are hardly taken at all by the other two squid-eating albatrosses at South Georgia. There are few detailed similarities between the squid taken by P. palpebrata at South Georgia and those recorded in an analysis of regurgitated pellets at Marion Island.Frequency of feeding of chicks and observations of birds at sea suggest that P. palpebrata can forage more widely during the breeding season than Black-browed and Grey-headed Albatrosses. Ecological segregation from these is thought to be achieved by a combination of differences in foraging range and area and by differences in the detailed composition of the diet.

DISPLAYS OF THE SOOTY ALBATROSSES PHOEBETRIA FUSCA AND P. PALPEBRATA

Summary Berruti, A. 1981. Displays of the sooty albatrosses Phoebetria fusca and P. palpebrata. Ostrich 52: 98–103 The displays of the Sooty Albatross Phoebetria fusca and the Lightmantled Sooty Albatross P. palpebrata which breed sympatrically at Marion Island (46 54S; 37 45E) are described. No hybridization or courtship display has been recorded between P. fusca and P. palpebrata. Possible isolation mechanisms at Marion Island are partial segregation of nest sites, a two-week difference in the initiation of breeding, and the ability of each species to recognize the other. Should courtship display start between individuals of the two species, the performance of the first mutual display by one bird would be inappropriate to the other, and would probably prevent pair formation. The first mutual display viz Bill Clashing in P. fusca and Bill Thrusting in P. palpebrata, is the major qualitative difference in the display repertoire of the two species. Other differences in morphology, voice and posture do exis...

The Breeding Biologies of the Sooty Albatrosses Phoebetria Fusca and P. Palpebrata

The breeding biologies of the Sooty Albatross Phoebetria fusca and the Light-mantled Sooty Albatross P. palpebrata were studied at Marion Island (46°54′S, 37°4.5′E), Prince Edward group of islands, one of only two (possibly three) groups where they breed sympatrically. Phoebetria fusca is far more abundant than P. palpebrata at Marion Island. The breeding biologies of the two species were similar; the pre-egg, egg and nestling periods of the breeding cycle are compared. There is an overlap in selection of nest sites but interspecific competition for nest sites is probably not sufficiently intense to limit either species. Giant-petrels Macronectes may be important predators of nestlings, specially those of fusca. Differences in the pelagic distribution of the two albatrosses and in the composition of their cephalopod prey suggests that palpebrata feeds mainly south of the Antarctic Convergence and thus has farther to fly to obtain food than fusca because the Antarctic Convergence lies south of Marion Island. Interspecific differences in shifts of brooding and incubation may be related to the greater distance that palpebrata must fly to obtain food. Elsewhere the nestling period of palpebrata is shorter than that of fusca. This is discussed in relation to the availability of food to the two species according to season. Phoebetria palpebrata may have difficulty supplying the nestling with sufficient energy to fledge, at least partly because palpebrata must fly farther than fusca to obtain food.

The composition, energy content and function of the stomach oils of petrels (order, procellariiformes)

The stomach oils of Diomedea epomophora Lesson, D. melanophris Temminck, D. chrysostoma Forster, D. bulleri Rothschild, Phoebetria palpebrata (Forster), Macronectes halli Mathews, Fulmarus glacialis (L.), Daption capense (L.), Pagodroma nivea (Forster), Pterodroma inexpectata (Forster), P. mollis (Gould), P. lessoni (Garnot), Procellaria aequinoctialis L., Puffinus tenuirostris (Temminck), P.griseus (Gmelin) and Hydrobates pelagicus (L.) have been analysed for lipid classes and energy contents. All oils contained 39–41 kJ/g. Triglycerides composed > 25 % of the oils in eleven species, whilst ten species contained comparable amounts of wax esters. Squalene comprised 28 % of the oil from Diomedea epomophora. Major lipid classes were not associated with any particular genera. A wide variety of fatty acid, fatty alcohol and glyceryl ether compositions were identified for the main components of each oil. That from Daption capense contained a unique composition of wax ester in which no C 14 or C 16 alcohols were present but significant proportions of myristic and palmitic acids were detected. The origin and function of the oils are discussed in terms of diet, preserving properties, water and energy stores, and defence.

Populations of Surface-nesting Seabirds at Marion Island, 1994/95–2002/03

During the 1990s and early 2000s, populations of surface-nesting seabirds at Marion Island showed different trends, but for the majority of species numbers decreased. Reduced numbers of gentoo penguins Pygoscelis papua, eastern rockhopper penguins Eudyptes chrysocome filholi, Crozet shags Phalacrocorax [atriceps] melanogenis and probably macaroni penguins E. chrysolophus are most plausibly attributed to an altered availability of food. Decreases in numbers of dark-mantled sooty albatrosses Phoebetria fusca, light-mantled sooty albatrosses P. palpebrata, southern giant petrels Macronectes giganteus and possibly northern giant petrels M. halli may have resulted from mortality of birds in longline fisheries. However, populations of wandering Diomedea exulans and grey-headed Thalassarche chrysostoma albatrosses fluctuated around a stable level. Numbers of Subantarctic skuas Catharacta antarctica and kelp gulls Larus dominicanus breeding at Marion Island also decreased. Kerguelen Sterna virgata and Antarctic S. vittata terns remain scarce at the island. Trends for king penguins Aptenodytes patagonicus were not reliably gauged, but numbers probably remained stable or increased. There were large fluctuations in numbers of king penguin chicks surviving to the end of winter.