Studying penguins on one of the remotest islands in the world

Blog by Dr Antje Steinfurth, Conservation Scientist, RSPB Centre for Conservation Science

After seven days at sea and looking at shades of grey and blue, the sight of Tristan da Cunha stretching on the horizon, was a true feast for the eye. The island’s classic volcanic shape is roughly 12 km across, with its summit 2060 m in height seemingly rising straight from the ocean. As we approached the island, the morning light just highlighted the valleys and gullies on the volcano flanks and snow-capped St. Mary’s Peak sneaked through the clouds.

We had left Cape Town on the 7 September. For the fourth time I find myself onboard the SA Agulhas II on my way to Tristan da Cunha helping to protect one of the islands most iconic yet threatened species – the northern rockhopper penguin.

Photo: 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).

Travelling to the UK’s remotest overseas territory

Tristan da Cunha is the UK’s remotest overseas territory and home to some of the richest and most diverse concentration of seabirds in the world. From the compelling human history to the unique flora and fauna, these islands have captured the hearts of many visitors. The northern rockhopper penguin Eudyptes moseleyi, or pinnamin, as the locals call their penguins, is one of Tristan’s most iconic species.

Photo: Northern rockhopper penguin, Eudyptes moseleyi

The penguin’s bobbing yellow hairdo and braying call is a familiar sight and sound for the Tristanians and, since people settled on Tristan in the early 1800s, the penguins have played a key role in the island’s traditions. However, a 90% decline in the population since the 19th century, combined with the penguin’s small breeding range and vulnerability to land- and sea-based threats, meant that when the species was recognised as a full species in 2008, it was immediately listed as Endangered by the International Union for the Conservation of Nature (IUCN).

The northern rockhopper is one of the five Endangered penguin species, and more than 80% of the northern rockhoppers are found in the UK 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 when the cargo ship MS Oliva ran aground off the north-western coast of Nightingale Island on 16 March 2011. Approximately 1500 tons of fuel and heavy crude oil escaped from the ship, encircling Nightingale and nearby Middle (or Alex) Islands, the breeding sites of almost half the world’s northern rockhoppers.

Photo: Northern rockhopper penguins on Nightingale Island in March 2011 after the oil spill.

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 reveal and highlight in a most striking manner 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.

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 and understanding factors that are driving population trends and dynamics, which is crucial for any decision-making and design of an adequate conservation strategy. Northern rockhopper penguin numbers are in decline and it is our job to find out why.

Photo: Northern rockhopper penguins on Nightingale Island

Studying northern rockhopper penguins

Spurred on by the unthinkable prospect of losing these charismatic, much loved and ecologically important birds, in 2015, the RSPB partnered up with the Tristan Conservation Department, the British Antarctic Survey, the Royal Zoological Society of Scotland and the South African Department of Environmental Affairs to propose a comprehensive rockhopper monitoring scheme to the UK Government’s Darwin Plus Overseas Territories Environment and Climate Fund. In March 2016, coinciding with the 5th anniversary of the oil spill, funding was awarded and Project Pinnamin was born.

Keeping track

Using a mixture of traditional observation and high-tech tracking tools, Project Pinnamin aims to investigate the penguin’s marine ecology, breeding biology and population dynamics to help understand the potential impact of any natural and/or anthropogenic threats to this population. To do so, we have been gathering tracking data from Nightingale, Gough and Inaccessible islands during different years and phases of the penguin’s annual cycle to quantify marine temporal and spatial habitat preference and hence recognise marine Important Bird Areas for this species in the South Atlantic. In parallel, numbers of breeding birds and reproductive performance has been investigated on Nightingale and Gough islands. Furthermore, in 2016, as an exciting new addition to the monitoring scheme, the project set up a demographic study to monitor survival rates, an important driver of population trends. Three hundred adult penguins and a hundred fledglings were fitted with PIT tags (Passive integrated transponders aka microchips) that 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 estimate survival rates and subsequently incorporated into population models.

Photo: Northern rockhopper penguins on Nightingale Island crossing the PIT reader.

Going rockhopping

I have been studying northern rockhoppers since 2012, initially as a Postdoc at the University of Cape Town, and since 2016 as a Conservation Scientist with the RSPB embedded in Project Pinnamin. With (austral) spring in the air and the penguin’s breeding season in full swing, in September, it was time once again for me to start my annual migration back to the islands.

Photo: Conservation Scientist Antje Steinfurth on Tristan da Cunha

On 13 September we arrived on Tristan da Cunha. Nightingale Island, my final destination, was already visible through binoculars only about 28 km away, so near but still far. While the next two days the crew was busy taking the passengers safely to Tristan and offloading the cargo I had to stay a little bit more patient. But I was in best company. Two Tristanians, Simon Glass and Matthew Green, came onboard to join me on my trip and during my time on Nightingale. On 15 September we finally set sail and steamed across. With the lobster fishing boat, the MFV Geo Searcher, nearby the water around the ship was now full of hopeful spectators. Giant Petrels, incessantly jeering and croaking, were bobbing expectantly on the water surface, waiting their chance to scavenge for scraps. Black-browed, sooty and yellow-nosed albatrosses, great shearwaters, broad-billed prions and smaller cape petrels were soaring the sky and amongst them the rare Tristan albatross, majestically flying by on broadsword wings. Occasionally rockhopper penguins popped up, looking simultaneously comical but furious due to the unruly tassels of yellow crest feathers above their eyes. It was difficult not to smile and indeed a grin split my face from ear to ear at the prospect of soon stepping foot onto the island.

Photo: Nightingale Island with Alex (Middle) and Stoltenhoff islands (from left to right)

While penguin colonies often resemble a bustling hive of activity, upon our arrival, life in the penguin colony was very quiet. Most eggs had been laid, males had left onto their forging trip and females were taking the first shift of incubating the eggs.

Photo: Northern rockhopper penguins incubating eggs

Where the wild birds go

Determining where penguins go during their winter migration has proved to be a difficult task with the main obstacle being attaching devices with enough battery life and memory capacity that will last sufficiently long to cover the entire period of migration. Miniature GLS technology enables us to use the changing light intensities associated with sunrise and sunset, coupled with an accurate clock, to determine locations for up to three years.

Usage of this technology however entails retrieving the devices in order to obtain the information and so the penguin has to be captured not only once, but twice. Crested penguins are known for a high nest-site and pair fidelity and therefore breeding birds have become the perfect target. In 2016 we equipped 20 males and 20 females in a small colony, individually marking birds (PIT tags) and nests (pegs) and one of my tasks for this year’s field season was to retrieve these devices. However, as so often, theory does not match practice and rest assured the penguins had us up for a good surprise: the whole colony was gone! We were lucky enough to learn that it hadn’t vanished but (only) moved. While this of course was a relief, truth be told, to the human eye, penguins do look quite alike, and so this blessing in disguise did come with a new challenge: Who is who in the new colony?

Who is who?

Fortunately, “our” penguins were bar coded (PIT tagged) so that “a scan of every single bird was all we had to do” she thought naïvely. While the multitude of adventure usually begins with embarking on the voyage the true challenge is summarized in only one sentence: on Nightingale Island, the penguins breed in tussock.

Photo: Tussock Grass, Spartina arundinacea dominates most of Nightingale Island

From the penguin’s point of view, being nestled into the depths of the high grass proves to be a wonderful protection not only against the elements but also against predation from the air. However it poses a logistical challenge for the field worker, who has to follow the penguins into their nesting grounds.

Photo: Fieldworker crawling through the penguin colony

The colony contains about 400 breeding pairs on a jam-packed 300 m² and we managed to find 13 out of 20 females. Our reader system later confirmed that four females had not returned to the island (yet) after winter migration while males only returned from their (incubation) foraging trip shortly after my departure. But I was lucky enough to have colleagues on the island who were able to retrieve another 13 devices few weeks later. And the breeding season is not over yet! Weather turned and far too quickly our pick up from Nightingale Island had to be arranged.

Project Pinnamin is coming to an end in March 2018 and after the Tristanians will take over from here. To wrap up the project I spent another two weeks on Tristan da Cunha to share my experience and knowledge with the local community, have meetings with the Island administration and conservation department and my personal highlight, to talk to the kids at school.

Conserving nature, preserving cultures

After having spent more time on Nightingale Island than any of the islanders, Tristan da Cunha has truly become my home away from home and, once again, I am deeply indebted to the islanders’ 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, by the uniqueness of this place.

The islands face different challenges today than in the past. Without doubt, science and research plays a key role in the conservation of species, habitats and ecosystems. Nevertheless, it is only the local community who can achieve lasting conservation success.