Mariette Wheeler (Animal Demography Unit, University of Cape Town, South Africa) and colleagues published in the African Journal of Marine Science in 2013 on the effects of human disturbance on Grey-headed Albatrosses Thalassarche chrysostoma breeding on South Africa’s Marion Island.

The paper’s abstract follows:

“Nest monitoring is commonly used to gather important seabird demographic data, but monitoring itself can affect seabird behaviour and offspring survival.  The effect of monitoring on grey-headed albatrosses Thalassarche chrysostoma at Subantarctic Marion Island was investigated.  The behaviour of chicks close to fledging and of brooding adults was recorded in research and non-research sections of the colony.  This was done prior to, during and after researcher/s entered the research sections of the colony.  During disturbance, both chicks and adults in research sections were more likely to be standing and to be more responsive than during the pre-disturbance phase.  However, adults appeared to be more sensitised to disturbance and this is likely because of being previously handled.  Offspring survival in research sections was compared with survival in (a) sections less-frequently entered (2004/2005) and (b) sections monitored through fixed-point photography (2005/2006 and 2006/2007).  In February of each of the three years of study, offspring survival was 62.5%, 55.8% and 71.8% respectively.  Disturbance level, size of section and the interaction of these two factors did not explain significant amounts of the among-section survival variance, but rainfall explained almost all of the temporal variation in offspring survival in 2006/2007.  Although research activities influenced the short-term behavioural responses of chicks and adults in the research sections of the colony, it did not seem to influence the survival of offspring.  Nevertheless, fixed-point photography is recommended as a non-intrusive monitoring method.”

A Grey-headed Albatross study colony on Marion Island, photograph by Kim Stevens 

Click here for a related ACAP Latest News item on disturbance effects on albatrosses at Marion Island.

Selected Literature:

de Villiers, M.S., Cooper, J. & Ryan, P.G. 2005.  Individual variability of behavioural responses by Wandering Albatrosses (Diomedea exulans) to human disturbance.  Polar Biology 28: 255-260.

Wheeler, M., de Villiers, M.S. & Altwegg, R. 2013.  Effect of human disturbance on the behavioural responses and offspring survival of grey-headed albatrosses Thalassarche chrysostoma at Subantarctic Marion Island.  African Journal of Marine Science 35: 533-543.

Wheeler, M., de Villiers, M.S. & Majiedt, P.A. 2009.  The effect of frequency and nature of pedestrian approaches on the behaviour of wandering albatrosses at sub-Antarctic Marion Island.  Polar Biology 32: 197-205.

John Cooper, ACAP Information Officer, 13 February 2015

Each year since the early 1980s, a team of ornithological researchers at South Africa’s Marion Island in the southern Indian Ocean has undertaken a round-island hike to count incubating Wandering Albatrosses Diomedea exulans.

This year a combined group of five employed by the FitzPatrick Institute, University of Cape Town and Branch: Oceans & Coasts, Department of Environmental Affairs undertook the census over the last two weeks of January.  Teams of one to three persons headed out to field huts around the island and counted every occupied nest in 25 sectors to allow for year-to-year comparisons.

A total of 1787 incubating nests was found.  This compares with a range of 1760 to 2056 annually breeding pairs over the five years, 2010 to 2014.

Similar censuses of Wandering Albatrosses have been undertaken this year at other sub-Antarctic islands where the species breeds, such as Bird in the South Atlantic and Macquarie in the southern Pacific.

All occupied nests visited were checked for the presence of eggs and bands on the incubating birds.  Recording of GPS coordinates will help these banded birds being traced in future years.  A total of 119 banded birds was found outside three long-term demographic study colonies - where all breeding birds are both metal and colour-banded and nests are staked.  Of this total, eight incubating adults bore metal bands beginning with the prefix BS, denoting them as having been banded on Île de la Possession in the French Crozet Islands, some 1100 km to the east of Marion Island.

However, a previous study has shown that not all French-banded birds recorded at the Prince Edward Islands were necessarily bred on the Crozets, although some undoubtedly were, as explained in the following abstract.

“Exchange of 61 wandering albatrossesDiomedea exulans has been recorded between the French Crozet Islands and the South African Prince Edward Islands, 1 068 km apart in the Southern Ocean.  Most movements of banded birds (57) have been westwards, from the Crozets to the Prince Edwards.  In all, 18 fledglings banded at Possession Island, Crozets, have bred at Marion Island, Prince Edwards, but only one fledgling from Marion Island has been recorded breeding on Possession.  The wandering albatrosses of the two island groups form a metapopulation that ideally should be conserved as a single unit.  It is suggested that France and South Africa collaborate through the Agreement on the Conservation of Albatrosses and Petrels to effect [sic] an improved conservation status for the wandering albatrosses of the two island groups.”

With thanks to Alexis Osborne, Liezl Pretorius and Peter Ryan for information and photographs

References:

Cooper, J. & Weimerskirch, H. 2003.  Exchange of Wandering Albatrosses Diomedea exulans between the Prince Edward and Crozet Islands: implications for conservation.  African Journal of Marine Science 25: 519-523.

Ryan, P.G., Jones, M.G.W., Dyer, B.M., Upfold, L. & Crawford, R.J.M. 2009.  Recent population estimates and trends in numbers of albatrosses and giant petrels breeding at the sub-Antarctic Prince Edward Islands.  African Journal of Marine Science 31: 409-471.

John Cooper, ACAP Information Officer, 12 February 2015

Following on the activities of BirdLife International’s Albatross Task Force tackling the problem of seabird bycatch in Southern African and South American countries, the European Seabird Task Force has been established this month to work in a similar with fishers in Europe (click here).

The current focus is on demersal longlines and set gillnets, two fishing gears thought to be responsible for high numbers of seabird bycatch in Europe.  Activities are concentrating in the Baltic Sea in Lithuania (where gill nets drowning sea ducks and other diving species is the issue) and in the Spanish Mediterranean, where longlines kill shearwaters, including the ACAP-listed and Critically Endangered Balearic Shearwater Puffinus mauretanicus and the Vulnerable Yelkouan Shearwater P. yelkouan, a potential candidate for ACAP listing (click here).

Balearic Shearwater at sea

Although recently published information suggests a larger population of Mediterranean-endemic Balearic Shearwaters than was previously thought (click here), concern is still expressed in a press release by SEO (BirdLife partner in Spain) on its conservation status, with its global population decreasing in size (click here).

Click here for the Spanish version of the press release.

With thanks to Pep Arcos for information

John Cooper, ACAP Information Officer, 11 February 2015

News from the Mainichi newspaper’s website of problems facing Streaked Shearwaters Calonectris leucomelas from feral Domestic Cats Felis catus on a Japanese island follows.

Streaked Shearwater on Mikura Island, photograph courtesy of Nariko Oka

“A Chiba Prefecture-based research institute is looking for cat lovers to adopt kittens of feral cats inhabiting a Tokyo island in a bid to protect seabirds that nest there.

Some 90 percent of the streaked shearwater, a species of seabird, is found in Japan, and Mikura Island, a Tokyo island about 5 kilometers in diameter, is the largest home to the species. They inhabit the island from around March to November each year. In recent decades, the seabird's numbers have been falling mainly as feral cats living on the island feed on them.

Senior researcher Nariko Oka at Yamashina Institute for Ornithology expresses concern over the safety of the species, saying that seabirds like the streaked shearwater that breed in groups may face risk of drastic decline in number if we overlook possible causes, in the way the albatross was driven to become an endangered species.

In a Tokyo Metropolitan Government study conducted in 1978, the number of the streaked shearwater living on Mikura Island was estimated to be between 1.75 million and 3.5 million. According to an Environment Ministry study in 2007, however, the figure had dropped to 880,000, and then to 770,000 in 2012, meaning that the figure has been falling by some 20,000 a year.

Experts believe that feral cats on the island are the main cause of the declining streaked shearwater population. The number of feral cats has grown as more people started moving in and out of the island since the 1990s, and people sometimes abandoned their domesticated cats. Oka estimates the number of feral cats on the island to be around 500.

Since fiscal 2005, the municipal government of Mikura Island has captured a total of 389 feral cats, neutering or spaying them to reduce their numbers, but most of them are released on the island after their operation.”

A feral kitten captured on Mikura Island, photograph courtesy of Nariko Oka

“Oka says, ‘Leaving feral cats that have high hunting ability will put numerous kinds of wild animals on the island in danger of extinction.’

The institute is using measures taken on the Ogasawara Islands, a UNESCO world heritage site, as an example, and is looking for people outside Mikura Island who can offer new homes to those feral cats.

According to the Environment Ministry, feral cats feeding on wild animals has become a serious concern on remote islands across the country, including Teuri Island in Hokkaido, Kagoshima Prefecture's Amami Oshima islands and Tokunoshima Island, as well as the northern part of the main island of Okinawa Prefecture.

Oka says feral cat adoption is scheduled to begin on Mikura Island this fall with cooperation from the municipal government, the Tokyo Veterinary Medical Association and other parties. As a trial, the institute is looking for homes off the island for kittens as they adapt to living with humans relatively easily.”

Click here to access other items in ACAP Latest News on Streaked Shearwaters.

John Cooper, ACAP Information Officer, 10 February 2015