A Southern Giant Petrel chick begs for food, watercolour by ABUN artist Shary Weckwerth; after a photograph by Michelle Risi

Ted Lownie (Department of Biology, Dalhousie University, Halifax, Canada) and colleagues have published in the journal Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology on oxygen-carrying capacity of breeding giant petrels Macronectes spp,

The paper’s abstract follows

“Reproduction, and parental care in particular, are among the most energy-demanding activities within the annual cycle of adult birds. Parents that cannot meet the metabolic demands and other physiological costs of raising offspring may opt to abandon chicks in favour of self-maintenance and future reproduction. Recent work examining reproductive trade-offs in birds revealed an important role of oxygen carrying capacity in mediating variation in parental effort. This study explores the aerobic factors underlying the success or failure of parental care in two closely-related petrel species during their breeding season on Bird Island, South Georgia: northern giant petrels (Macronectes halli) and southern giant petrels (M. giganteus). Failed breeders of both sexes and species had significantly lower hematocrit levels (by 5.48 ± 0.64%) than successful breeders, and reticulocyte counts also tended to be lower in failed males, consistent with the hypothesis that parental care and workload depend on aerobic capacity. We discuss these results in relation to differences in the foraging ecology of both species and sexes.”

With thanks to Richard Phillips, British Antarctic Survey.

Reference:

Lownie, T., Jubinville, I., Williams, T.D., Phillips, R.A. & Crossin, G.T. 2022.  Varying aerobic capacity in relation to breeding stage and reproductive success in giant petrels (Macronectes spp.).  Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology  266. 111155.

John Cooper, ACAP Information Officer, 24 January 2022

 
Age-related variation in the plumage of Short-tailed Albatrosses

NOTE:  This post continues an occasional series that features photographs of the 31 ACAP-listed species, along with information from and about their photographers.  Here, Naoki Tomita illustrates the Vulnerable Short-tailed Albatrosses Phoebastria albatrus that he studies on Torishima, the species’ main breeding locality.  Naoki is a Researcher in the Division of Avian Conservation at the Yamashina Institute for Ornithology in Japan.

Naoki Tomitsa on Torishima; photograph by Masayoshi Kamioki

Torishima, home of the Short-tailed Albatross

Landing and unloading on Torishima; photograph by Masayoshi Kamioki

On the island we stay in a weather station that was used until 1965 and is being repaired

The crater of Mount Iwo-yama, an active volcano on Torishima.  There were pyroclastic flow eruptions in 1902 and 1939, and a recent small eruption in 2002

The Short-tailed Albatross was recently described as a species complex comprising two genetically and morphologically distinct populations (Torishima and Senkaku types), with assortative but incomplete mating between birds of both types on Torishima. (from left to right: a female and a male of the Torishima type, two females of the Senkaku type).  The Torishima type is larger in overall size than the Senkaku type.  Read more here; photograph by Miwa Konno

The Tsubamezaki Colony in the distance where Short-tailed Albatrosses were rediscovered breeding in 1951.  It is necessary to descend the cliff using a rope

The Tsubamezaki Colony.  Because of the steep slope, eggs and chicks can roll out of the nest; in addition, heavy rains cause scoria to flow down from the cliff

Young Short-tailed Albatrosses gather at sea near Torishima

Two Short-tailed Albatrosses engage in a courtship display

Researchers (Naoki Tomita second left) with their World Albatross Day 2020 banner.  The Hatsunezaki Colony shown here was artificially established in 1995 by attracting birds using decoys and audio devices; photograph by Miwa Konno

Photographs by Naoki Tomita unless stated.

Selected Publications:

Eda, M., Yamasaki, T., Izumi, H., Tomita, N., Konno, S., Konno, M., Murakami, H. & Sato, F. 2020.  Cryptic species in a Vulnerable seabird: short-tailed albatross consists of two species.  Endangered Species Research . 43: 375-386.

Nishizawa, B., Thiebot, J.-B., Sato, F., Tomita, N., Yoda, K., Yamashita, R., Takada, H. & Watanuki, Y. 2021.  Mapping marine debris encountered by albatrosses tracked over oceanic waters.  Scientific Reports  doi.org/10.1038/s41598-021-90417-x.

Senzaki, M., Terui, A., Tomita, N., Sato, F., Fukuda, Y., Kataoka, Y. & Watanuki, Y. 2019.  Long-term declines in common breeding seabirds in Japan.  Bird Conservation International: 30: 434-446.

Thiebot, J.-B., Nishizawa, B., Sato, F., Tomita, N. & Watanuki, Y. 2018.  Albatross chicks reveal interactions of adults with artisanal longline fisheries within a short range.  Journal of Ornithology 159: 935-944.  (video of metal detector in use in supplementary material).

Tsukamoto, S., Nishizawa, B., Sato, F. & Tomita, N. & Watanuki, Y.  2019.  Determination of on-water and feeding activities of Black-footed Albatrosses using acceleration and images.  Japanese Journal of Ornithology 68: 29-41.

Naoki Tomita, Division of Avian Conservation, Yamashina Institute for Ornithology, Abiko, Chiba, Japan, 21 January 2022, updated 22 January 2022

From the publication giant petrel skull at the top

Mariana Mazzochi and Caio Carlos (Laboratório de Sistemática e Ecologia de Aves e Mamíferos Marinhos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil) have published in the journal Polar Biology on the morphology of the skulls of fulmarine petrels, including giant petrels Macronectes spp.

The paper’s abstract follows:

Fulmarine petrels are top predators in the Antarctic region preying mostly on squid, fish, and carrion. Their diets have been widely studied, but less is known about the role of skeletal structures in the processes they use to obtain food. Here, we comparatively describe the skulls of fulmarine petrels, namely, the Giant Petrels (Macronectes), the Southern Fulmar (Fulmarus glacialoides), and the Cape Petrel (Daption capense), emphasizing those structures associated with the muscles responsible for opening/closing the jaws. The skull is dorsoventrally flattened and the bill is hooked-tipped and elongated in the studied species, but we found significant differences for relative bill length and relative cranium depth among them. These characteristics can be related to surface seizing and streamlining for diving and pursuing/capturing prey underwater. Longer bills also indicate that the mandible muscles are more posteriorly positioned relative to the bill tip, an adaptation for a fast bite, which is more pronounced in Giant Petrels. Nevertheless, there are broad areas of origin for the mandible muscles in the fossa musculorum temporalium and in the Os palatinum, especially in Giant Petrels. We thus infer that those muscles are well developed and hypothesize that, despite the adaptation for fast movements, their jaws are still capable of a relatively powerful bite. The Giant Petrels and Cape Petrel present a similar pattern of dorsoventral flattening of the skull, an adaptation for diving in pursuit of prey. In Giant Petrels, a flattened skull with a hooked-tipped bill also facilitates their feeding behavior of inserting the bill and head into carcasses for tearing flesh. We conclude that fulmarine petrels present variable morphological characters adapted to the different feeding strategies they employ in the Antarctic and the Southern Ocean.”

Reference:

Mazzochi, M.S. & Carlos, C.J. 2022.  Skull morphology of four Antarctic fulmarine petrels (Aves: Procellariiformes): insights into their feeding biology.  Polar Biology  doi.org/10.1007/s00300-021-02983-5.

John Cooper, ACAP Information Officer, 20 January 2022

 
Wandering Albatross tracks in blue, White-chinned Petrel tracks in red

Satellite transmitters have been deployed this month on White-chinned Petrels Procellaria aequinoctialis (Vulnerable) on Cooper Island and on Wandering Albatrosses Diomedea exulans (Vulnerable) on Prion Island, as part of a project on the spatial segregation of seabirds at South Georgia (Islas Georgias del Sur)*.  The project is being led by Vicky Warwick-Evans of the British Antarctic Survey and is funded by Darwin Plus.

Wandering Albatross and White-chinned Petrel at sea in the South Atlantic; photographs by Kirk Zufelt

This is stated to be the first tracking of any flying seabird species at South Georgia (Islas Georgias del Sur)* from a colony other than those on Bird Island (where both species are also being tracked this year).  The project aims to determine the degree of overlap in distribution of birds from different colonies, and the implications for fisheries overlap and population trends.

To read more about the project and view the tracks in near real-time and compare distributions click here.  Click on the “Data” tab to see an animation.

With thanks to Richard Phillips, British Antarctic Survey.

John Cooper, ACAP Information Officer, 19 January 2022

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.