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Read about recent developments and findings in procellariiform science and conservation relevant to the Agreement on the Conservation of Albatrosses and Petrels in ACAP Latest News.

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Acquiring individual strategies early in life: niche partitioning in Scopoli's Shearwaters

Scopolis Searwater John Borg

Scopoli's Shearwater at sea, photograph by John Borg

Laura Zango (Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Spain) and colleagues have published in the journal Animal Behaviour on niche partitioning in Scopoli's Shearwaters Calonectris diomedea.

The paper’s abstract follows:

“Niche partitioning among different age, breeding status or sex classes allows resource use to be maximized while reducing intraspecific competition. Individual specialization marks the finest scale of niche partitioning where, within a species, individuals differ in their realized niches. Despite having important implications in ecology, evolution and conservation, studies simultaneously addressing the occurrence of both phenomena are scarce. We studied niche partitioning and individual specialization in foraging behaviour in relation to age, breeding status and sex using breeding, nonbreeding adult and immature Scopoli's shearwaters, Calonectris diomedea, in Minorca (Balearic Is.) during chick rearing in 2017 with GPS loggers and stable isotopes. Compared to adults, immature birds seemed to exploit a larger area at the population level, possibly to avoid competition. We found similar levels of individual specialization in immature and adult birds, which suggests the former have well-defined foraging strategies prior to prospecting the colony. For breeding status, we did not find niche partitioning or differences in individual specialization, suggesting nest attachment and pair bonds also lead to central-place foraging in nonbreeding adults. Male breeders showed greater individual specialization than female breeders in trip characteristics. At the same time, individual specialization in isotopic diet was higher in females than in males. These opposite patterns are possibly driven by a greater use of fishery discards by males, which would underlie their individual strategies of following vessels, resulting in a highly variable diet, since discarded prey types vary more than naturally accessible prey. Our results suggest that seabirds acquire individual strategies early in life and, once they are sexually mature, breeding constraints do not result in differences in feeding behaviour between breeders and nonbreeders. Finally, we showed that sexual differences in individual specialization can apparently emerge even in slightly dimorphic species sharing breeding duties.”

Reference:

Zango, L., Navarro-Herrero, L., García-Vendrell, M., Safi, K. & González-Solís, J. 2020.  Niche partitioning and individual specialization among age, breeding status and sex classes in a long-lived seabird.  Animal Behavour doi.org/10.1016/j.anbehav.2020.10.001.

John Cooper, ACAP Information Officer, 10 December 2020

Post-fast faeces – Southern Giant Petrels practice coprophagy in Antarctica

Signy 3 Michael Dunn s 

White-phase Southern Giant Petrel in Antarctica, photograph by Michael Dunn

Denyelle Corá (Universidade Comunitária da Região de Chapecó, Curso de Ciências Biológicas, Brazil) and colleagues have published in the journal Polar Biology on coprophagy by breeding Antarctic Southern Giant Petrels Macronectes giganteus.

The paper’s abstract follows:

“Southern giant petrels (Macronectes giganteus) are opportunistic generalists whose feeding strategies include hunting, scavenging and fishing.  While seals are important for southern giant petrels as a source of carrion, we documented that live seals also provide feeding opportunities for southern giant petrels.  We tracked breeding southern giant petrels from Harmony Point, Antarctica, during incubation and chick rearing with solar-powered GPS-UHF devices.  Tracking results showed that animals often visited confirmed haul-out sites of seals, mainly Weddell seals (Leptonychotes weddellii).  Feeding on seal faeces was confirmed by direct observation. Southern giant petrels were more likely to visit haul-out sites during incubation than during chick-rearing.  This behaviour suggests that the birds fed on seal faeces mainly when fasting, which could last as long as 15 days.  Seal faeces could be a resource consumed to quickly recover from the fast before leaving for a longer trip.”

Reference:

Corá, D.H., Finger, J.V.G. & Krüger, L. 2020.  Coprophagic behaviour of southern giant petrels (Macronectes giganteus) during breeding period. Polar Biology 43: 2111–2116.

John Cooper, ACAP Information Officer, 09 December 2020

Plumage development influences heat loss in Wandering Albatross chicks

 Wandering Albatross chick South Georgia Kirk Zufelt

Floof!  Wandering Albatross chick in the South Atlantic, photograph by Kirk Zufelt

David Stone (Scottish Centre for Ecology and the Natural Environment, University of Glasgow, UK) and colleagues have published in the Journal of Thermal Biology on aspects of homeothermy in Wandering Albatross Diomedea exulans chicks.

The paper’s abstract follows:

“Young birds in cold environments face a range of age-specific thermal challenges. Studying the thermal biology of young birds throughout ontogeny may further our understanding of how such challenges are met. We investigated how age and environmental parameters influenced surface temperature gradients across various body regions of wandering albatross (Diomedea exulans) chicks on Bird Island, South Georgia. This study was carried out over a 200 d period during the austral winter, from the end of the brood-guard period until fledging, bridging a gap in knowledge of surface temperature variation and heat loss in developing birds with a long nestling stage in severe climatic conditions. We found that variation in surface temperature gradients (i.e., the difference between surface and environmental temperature) was strongly influenced by chick age effects for insulated body regions (trunk), with an increase in the surface temperature gradient that followed the progression of plumage development, from the second set of down (mesoptiles), to final chick feathers (teleoptiles). Environmental conditions (primarily wind speed and relative humidity) had a stronger influence on the gradients in uninsulated areas (eye, bill) than insulated regions, which we interpret as a reflection of the relative degree of homeothermy exhibited by chicks of a given age. Based on biophysical modelling, total heat loss of chicks was estimated to increase linearly with age. However, mass specific heat loss decreased during the early stages of growth and then subsequently increased. This was attributed to age-related changes in feather growth and activity that increased surface temperature and, hence, metabolic heat loss. These results provide a foundation for further work on the effects of environmental stressors on developing chicks, which are key to understanding the physiological responses of animals to changes in climate in polar regions.”

Reference:

Stone, D.W., Gunn, C., Nord, A., Phillips, R.A. & McCafferty, D.J. 2020.  Plumage development and environmental factors influence surface temperature gradients and heat loss in wandering albatross chicks.  Journal of Thermal Biology  doi.org/10.1016/j.jtherbio.2020.102777.

John Cooper, ACAP Information Officer, 08 December 2020

Wisdom is back! The world’s oldest known albatross is incubating once more on Midway Atoll

 2020 Nov. Wisdom incubating Jon Brack Friends of Midway Atoll NWR

Wisdom incubates her latest egg last month, with her red Z333 colour band visible; photograph by Jon Brack, Friends of Midway Atoll NWR

Following taking a ‘gap year’ in the 2019/20 breeding season, Wisdom, the world’s oldest known Laysan Albatross Phoebastria immutabilis, and her current mate Akeakamai, have returned to Midway Atoll and are incubating an egg.

Extracts from a post by the U.S. Fish and Wildlife Service: Pacific Islands follow:

“Wisdom, is a Mōlī (Laysan Albatross) and the world’s oldest known, banded wild bird has returned to Midway Atoll National Wildlife Refuge and Battle of Midway National Memorial.  At least 69 years old, the first observation of Wisdom at her nest site took place on November 29, 2020.  Biologists have confirmed that she has laid an egg.  Each year millions of albatrosses return to Midway Atoll in Papahānaumokuākea Marine National Monument to nest and raise their young.   Culturally, albatross species are kinolau (body form) of the Hawaiian deity Lono.  The birds’ return to land for mating coincides with the beginning of the makahiki season [Hawaiian New Year] occurring between October and November, and an important aspect to some practitioners’ ceremonies and practices during that time.

“Every year that Wisdom returns, she is rewriting what we know about albatross longevity — and inspiring the next generation,” said U.S. Fish and Wildlife Service Monument Superintendent Jared Underwood. “Wisdom helps us better understand how long these birds live and how often they breed. This knowledge informs our management actions to ensure a future for albatrosses that rely on the Refuge and Monument.”

“Wisdom and her mate have met on Midway Atoll to lay and hatch an egg almost every year since 2006.  Wisdom has laid between 30–36 eggs in her lifetime.  In 2017, the chick that she fledged in 2001 was observed just a few feet away from her current nest, marking the first time a returning chick of hers has been documented.”

Access the many posts to ACAP Latest News featuring Wisdom; and read more on her breeding activity over the last decade.

John Cooper, ACAP Information Officer, 07 December 2020

An unreported use: yellow-nosed albatross wings adorned a Cape Town rickshaw puller in the 1900s

 Rickshaw albatross wings

“A jinrickshaw in Cape Town”, from the Cape of Diab Facebook group

In the past albatrosses and their eggs were exploited in various ways, mainly for food, but also for cultural purposes, as notably occurred in Hawaii (to be covered in a future post).

A hitherto unreported cultural (or at least decorative) use is depicted in an old postcard that has recently come to light.  Thought to be from around 1900 (late Victorian/early Edwardian), the photo from South Africa’s Cape Town shows a rickshaw puller with a pair of yellow-nosed albatross wings (not identifiable to species) strapped to his upper arms.  This is the only known case of such a use found.  Perhaps he found them washed up on the shore, or obtained them from a fishing vessel. In the same era, rickshaw pullers in South Africa tended to a cow horn head dress, presumably as an aid to attracting clients.  Just a few rickshaws survive in the country in Durban, aimed at the tourist trade.

Durban rickshaw pullers

 Durban rickshaw cow horns colour

Headdresses worn by Durban rickshaw pullers: past and present

With thanks to Michael Fortune and Peter Ryan.

John Cooper, ACAP Information Officer, 04 December 2020

The Agreement on the
Conservation of Albatrosses and Petrels

ACAP is a multilateral agreement which seeks to conserve listed albatrosses, petrels and shearwaters by coordinating international activity to mitigate known threats to their populations.

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