ACAP Latest News

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.

Mid-air attack on a Black-browed Albatross fledgling by skuas and giant petrels at Bird Island

Having developed from egg to fledgling over the last seven to eight months, the Black-browed Thalassarche melanophris and Grey-headed T. chrysostoma Albatross chicks at Bird Island, South Georgia (Islas Georgias del Sur)* have been departing recently on their inaugural flights over the Southern Ocean.  It is rare to see the precise moments of their first flights, but albatross zoological field assistant Lucy Quinn witnessed just such an event from one of the colonies near the research station, where the albatross populations have been monitored for more than 30 years.  She reports to ACAP Latest News:

"The first flight of one Black-browed Albatross fledgling was ungainly and, unfortunately, was to be its last.  It was not flying particularly strongly, flapping rapidly just to stay airborne, but was at least heading out to sea. However, within 10 seconds of take-off two Subantarctic Skuas Catharacta antarcticus appeared (based on their degree of coordination they were likely a pair), and took it in turns to harass the fledgling and peck at its back.  They were quickly joined in flight by three Northern Giant Petrels Macronectes halli.  Apparently trying to escape, the fledgling turned back towards land.  As the skuas continued to harass the albatross from above, one of the giant petrels came from below to seize its tail, eventually downing the bird.  The giant petrels landed, followed closely by the skuas.  In total, the entire predation event took less than six minutes from the time the chick left its nest.  The giant petrels then killed and consumed the fledgling.

A Black-browed Albatross chick close to fledging in a study colony on Bird Island, photograph by Lucy Quinn

A Subantarctic Skua feeds on the carcass of an albatross chick on Bird Island, photograph by Lucy Quinn

Giant petrels are the main predators of albatross chicks on Bird Island around the time of fledging, photograph by Alastair Wilson 

Another fledgling was seen being harried in flight later the same day.  This behaviour has not been reported before at Bird Island and begs the question as to how many albatross chicks are depredated shortly after fledging, either on their first flight or close to land before their flying skills are well developed."

With thanks to Andy Wood.

Lucy Quinn, British Antarctic Survey, Cambridge, United Kingdom, 17 May 2015

*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.

“Live long and prosper”. Northern Royal Albatrosses are doing well at New Zealand’s Taiaroa Head

Yvan Richard (Dragonfly Science, Wellington, New Zealand) and colleagues have published open access in the online journal PeerJ on aspects of the demographic rates of Northern Royal Albatrosses Diomedea sanfordi that breed on Taiaroa Head on New Zealand’s South Island.

The paper’s abstract follows:

“Demographic rates, such as annual survival rate, are generally difficult to estimate for long-lived seabirds, because of the length of time required for this kind of study and the remoteness of colonies.  However, a small colony of northern royal albatross (Diomedea sanfordi) established itself on the mainland of New Zealand at Taiaroa Head, making possible regular banding and monitoring of its individuals since the first chick fledged, in 1938.  Data on the presence/absence of birds, as well as on breeding outcomes, were available for the period from 1989–90 to 2011–12, and included 2128 annual resightings of 355 banded individuals of known age.  The main goal of the present study was to estimate the annual survival rate of juveniles, pre-breeders, and adults at Taiaroa Head.  These rates were estimated simultaneously in a single Bayesian multi-state capture-recapture model.  Several models were fitted to the data, with different levels of complexity.  From the most parsimonious model, the overall annual adult survival rate was estimated as 0.950 (95% CI [0.941–0.959]). In this model, adult survival declined with age, from 0.976 (95% CI [0.963–0.988]) at 6 years, the minimum age at first breeding, to 0.915 (95% CI [0.879–0.946]) at 40 years.  Mean annual survival of pre-breeders was 0.966 (95% CI [0.950–0.980]), and 0.933 (95% CI [0.908–0.966]) for juveniles.  There was no discernible difference in survival between males and females, and there was no apparent trend in survival over time.  Estimates of other demographic rates were also obtained during the estimation process. The mean age at first return of juveniles to the colony was estimated as 4.8 years (95% CI [4.6–5.1]), and the mean age at first breeding as 8.9 years (95% CI [8.5–9.3]).  Because all the birds of the colony were banded, it waas possible to estimate the total population size.  The number of northern royal albatross present annually at the Taiaroa Head colony has doubled since 1989–90, and the current total population size was estimated to be over 200 individuals.  The ratio of the total population size to the number of annual breeding pairs varied from5 to 12 among years, with an overall mean of 7.65 (95% CI [7.56–7.78]), and this high variability highlights the need for a sufficient number of surveys of seabird breeding populations before reliable conclusions on population trends can be made.  Although long-term data allowed estimates of demographic rates of northern royal albatross at Taiaroa Head, the location of the colony and the ongoing management by staff mean that the population dynamics may differ from those of the main population on the Chatham Islands.”

 

Nothern Royal Albatross and chick at Taiaroa Head, photograph by Lydon Perriman

With thanks to Barry Baker for information.

Reference:

Richard, Y., Perriman, L., Lalas, C. & Abraham, E.R. 2015.  Demographic rates of northern royal albatross at Taiaroa Head, New Zealand.  PeerJ 3:e906.  DOI 10.7717/peerj.906

John Cooper, ACAP Information Officer, 17 May 2015

Wandering Albatrosses are decreasing on a South Atlantic Island

The following shortened report by Jennifer Lee gives preliminary news of a recent survey of breeding Wandering Albatrosses Diomedea exulans on South Georgia (Islas Georgias del Sur)*.

“In early January a team of intrepid scientists and tourists embarked on a unique collaborative expedition to survey South Georgia’s outlying wandering albatross colonies.  The last island-wide survey took place in 2004 and showed a 30% decline since the survey in 1984.

The aim of the expedition was to visit all the known wandering albatross breeding sites outside of the large colonies at Bird Island and Annenkov Island.  The population at Bird Island is surveyed each year but it is important to periodically visit smaller colonies to understand the trends in abundance and distribution on South Georgia as a whole.  Logistic constraints meant it was not possible to visit Annenkov Island this year but a survey is planned for 2016.

Between January 9th and 20th 2015, scientists visited 25 sites from the Bay of Isles to Cape Disappointment.  Counts ranged from having 34 wandering albatross nests with eggs at Cape Alexandra, to just a single pair at Mollyhawk Island.  In the coming months the survey data from the South Georgia mainland will be combined with survey data from Bird Island and analysed more fully, but early indications are that populations are down approximately 15% from the survey in 2004.  The decline matches with the annual trends that have been seen on Bird Island and give a clear indication that more work to save the wandering albatross is needed.

A major component of the population decline of this great ocean nomad is likely to be due to mortality associated with fisheries.  Although in the last decade, no wandering albatross have been killed by vessels in South Georgia waters, the wide foraging range of this species means it is vulnerable to fisheries operating elsewhere in the South Atlantic and beyond.”

Wandering Albatross on Prion Island, photograph by Anton Wolfaardt

Click here to access the full news item and here for an earlier report in ACAP Latest News on the survey.

John Cooper, ACAP Information Officer, 15 May 2015

*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.

Breeding of the Wedge-tailed Shearwater in the Freeman Seabird Preserve, Hawaii

Harrison Pravder (Department of Biology, Washington University in St. Louis, USA) and colleagues have published in the Journal of the Hawai‘i Audubon Society 'Elepaio on the breeding phenology of the Wedge-tailed Shearwater Puffinus pacificus on the Hawaiian island of Oahu.

Although it has no abstract the full paper is available free-access on line. "The goal was to document the timing of egg laying and chick hatching, to obtain more up to date breeding phenology data, and to estimate the duration of incubation for the species at this breeding location."

 

Wedge-tailed Shearwater, photograph by Alan Burger

Reference:

Pravder, H., Prestridge, C. & Hyrenbach, K.D. 2015.  Wedge-tailed Shearwater breeding phenology at the Freeman Seabird Preserve, Oʻahu, Hawaiʻi.  'Elepaio 75: 17-21.

John Cooper, ACAP Information Officer, 14 May 2015

Bait trials on tropical islands: how best to eradicate rodents?

Madeleine Pott (Island Conservation, Santa Cruz, USA) and colleagues have published in the journal Biological Conservation on bait trials for rodent eradications on tropical islands.  One of the islands studied in the paper is Wake Atoll, a marginal breeding site for Laysan Albatrosses Phoebastria immutabilis (click here).

The paper’s abstract follows:

“Rodent eradications undertaken on tropical islands are more likely to fail than eradications undertaken at higher latitudes.  We report on 12 independent rodent eradication projects undertaken on tropical islands that utilized the results of an in situ bait availability study prior to eradication to inform, a priori, the bait application rate selected for the eradication.  These projects also monitored bait availability during the eradication.  The results from our analysis verified the utility of bait availability studies to future rodent eradication campaigns and confirmed the influence of two environmental factors that can affect bait availability over time: precipitation prior to the study and the abundance of land crabs at the study site.  Our findings should encourage eradication teams to conduct in-depth assessments of the targeted island prior to project implementation.  However, we acknowledge the limitations of such studies (two of the projects we reviewed failed and one removed only one of two rodent species present) and provide guidance on how to interpret the results from a bait availability study in planning an eradication.  Study design was inconsistent among the twelve cases we reviewed which limited our analysis.  We recommend a more standardized approach for measuring bait availability prior to eradication to provide more robust predictions of the rate at which bait availability will decrease during the eradication and to facilitate future comparisons among projects and islands.”

A breeding Laysan Albatross

With thanks to Mike Brooke for information.

Reference:

Pott, M., Wegmann, A.S., Griffiths, R., Samaniego-Herrera, A., Cuthbert, R.J., Brooke, M de L., Pitt, W.C., Berentsen, A.R., Holmes, N.D., Howald, G.R., Ramos-Rendón, K. & Russell, J.C. 2015.  Improving the odds: assessing bait availability before rodent eradications to aid in selecting bait application rates.  Biological Conservation 185: 27-35.

John Cooper, ACAP Information Officer, 13 May 2015

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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