16/05/2017 in Conservation
Above: Tristan da Cunha - photo by Antje Steinfurth
Tucked away in the South Atlantic Ocean, mid-way between South Africa and South America, lies Tristan da Cunha, a true haven for seabirds and home of the endangered northern rockhopper penguin (Eudyptes moseleyi), or ‘pinnamin’, as the locals endearingly call their penguins.
The archipelago comprises three main islands: Inaccessible, Nightingale and Tristan da Cunha itself, with Tristan being the only island with a permanent settlement, Edinburgh of the Seven Seas. Nestled at the base of the volcano on the island’s north west coast, the village is home to about 270 inhabitants – the Tristanians. Gough Island, 380 km south southeast of the Tristan group, is a UNESCO World Heritage Site (together with Inaccessible Island) and the only breeding site for this penguin south of the Subtropical front.
Above: Rockhopper penguins on Alex Island with Nightingale Island in the background - photo by Antje Steinfurth
Approximately 85% of the world’s northern rockhopper penguins are found in the islands, which makes the species’ stronghold fall within the boundaries of the UK remotest overseas territory. This claim to fame, however, comes with some responsibility as it means that just one single catastrophe could prove disastrous to the global population.
This message was driven home in March 2011 when the cargo ship MS Oliva ran aground off the north western coast of Nightingale Island. Approximately 1,500 tonnes of fuel and heavy crude oil escaped from the ship, encircling Nightingale and adjacent Middle (or Alex) islands, the breeding sites of almost half the world’s northern rockhopper population.
Even though the oil spill had nothing to do with past population declines, nor might it be responsible for the fluctuations that followed, what the catastrophe did highlight was how little is known about this endangered species, and that basic but vital information on the species’ general ecology had been almost totally lacking.
Above: Rockhopper penguins Tristan da Cunha in the distance - photo by Antje Steinfurth
It goes without saying that regular surveys carried out by the Tristan Conservation Department have been providing an important and valuable tool to estimate annual population sizes, but are of little help identifying factors and understanding the mechanisms that are driving population trends and dynamics.
Northern rockhopper penguin numbers are in decline and it is our job to find out why. To do so, in 2015, the RSPB partnered up with the Tristan Conservation Department, the British Antarctic Survey, the Royal Zoological Society of Scotland (RZSS) and the South African Department of Environmental Affairs (DEA) to propose a comprehensive rockhopper monitoring scheme to the UK Government’s “Darwin Plus” Overseas Territories Environment and Climate Fund. In March 2016, funding was awarded and Project Pinnamin was born.
Project Pinnamin is a study of the marine ecology, breeding biology and survival of the northern rockhopper penguin, to identify the potential impact of any natural and/or anthropogenic threats to this population, allowing authorities to effectively tackle those issues.
With spring in the air and the penguin’s breeding season in full swing, the first field season of Project Pinnamin started in September 2016. To catch a glimpse of the penguin’s marine life, we use logger technology to investigate where the penguins are foraging, how deep they dive and what they eat.
During the field season from September to December 2016, 84 birds were deployed with devices at different phases of the penguin’s breeding and annual cycle to quantify marine habitat preference and recognise marine Important Bird Areas (mIBAs). Also, for the first time ever, ten females were equipped with GPS tags on nearby Inaccessible Island during chick rearing. In parallel, numbers of breeding birds and reproductive performance were monitored on Nightingale Island.
As an exciting new addition to the monitoring scheme, the project set up a demographic study to estimate survival rates, an important driver of population trends. Three hundred adult penguins and a hundred fledglings were microchipped which will be detected by sensors each time the penguins commute along their traditional routes to their colonies. Their presence or absence during successive years can then be used to compare year-on-year survival and mortality rates.
Conserving nature, preserving cultures
Last but not least, this was my third time in the islands and once again I was deeply indebted to the islanders for their unwavering support. Anybody who has ever been to Tristan knows it is unlikely that you leave the islands without being moved by the generosity and hospitality of the Tristanians, and by the uniqueness of this place.
The islands face, of course, different challenges today than in the past. Without doubt, science will play a key role in their conservation; however, we must not forget that in the main it is only with local community support that we can achieve long-term change. While some threats can be addressed by boots-on-the-ground conservationists on location, others like climate change cannot.
The protection and preservation of biological diversity is ultimately a shared mission - not only within the local community but on an international scale. It is incumbent on the international community to play an increasingly active role.
Conservation Scientist at the Royal Society for the Protection of Birds, Cambridge, UK
All photos © Antje Steinfurth