Seabird research

Coordinator

Assoc. Prof. Peter Ryan

Research team

Ms Viviane Barquete (PFIAO)
Dr Jacqueline Bishop (Zoology Department, UCT)
Ms Justine Braby (Animal Demography Unit, UCT)
Ms Mia Cerfonteyn (PFIAO)
Dr Timothée Cook (PFIAO)
Mr John Cooper (Centre for Invasion Biology, University of Stellenbosch)
Dr Rob Crawford (Marine and Coastal Management)
Dr Richard Cuthbert (Royal Society for the Protection of Birds, UK)
Dr Jacob Gonzalez-Solis (University of Barcelona, Spain)
David Grémillet (PFIAO & CNRS, Montpellier, France)
Dr Akiko Kato (CNRS, Strasbourg, France)
Alistair McInnes (PFIAO)
Ms Lisa Nupen (PFIAO)
Dr Samantha Petersen (WWF-SA)
Dr Lorien Pichegru (PFIAO)
Dr Richard Phillips (British Antarctic Survey, Cambridge, UK)
Dr Rob Ronconi (Dalhousie University, Canada)
Dr Yan Ropert-Coudert (CNRS, Strasbourg, France)
Mr Jean-Paul Roux (ADU & Ministry of Fisheries and Marine Resources, Namibia)
Dr Rob Simmons (PFIAO, UCT)
Prof. Les Underhill (Animal Demography Unit, UCT)
Mr Rowen van Eeden (PFIAO)
Dr Ross Wanless (BirdLife South Africa).

Programme overview

As a group, seabirds are among the most threatened birds in the world, with almost one third of all species included on the global Red List. Seabirds also dominate the list of globally threatened species at a regional level in southern Africa. They are vulnerable to human activities both at sea and at their breeding sites. Consequently, the Seabird Research Programme has a strong applied focus, assessing the magnitude of threats faced by various seabird species, and attempting to provide practical management solutions to mitigate against these threats. However, because many seabirds are easily observed and caught at their breeding colonies, they also provide excellent models for testing ecological and evolutionary theories. The programme thus includes several studies of a more academic nature. It forms the bulk of Peter Ryan’s research activities, and overlaps to some extent with the Island Conservation programme.

Foraging ecology and conservation of African Penguins

Research team: Lorien Pichegru, Peter Ryan, Rob Crawford, Ross Wanless & David Grémillet

Numbers of African Penguins Spheniscus demersus have fallen dramatically in the last decade, decreasing by up to 60% in the last five years. The main cause of this decline apparently is the lack of food close to breeding colonies. Since the late 1990s, stocks of small pelagic fish (anchovies and sardines), which form the main prey of African Penguins, have shifted progressively south and east away from the west coast of South Africa. To counter these trends, Marine and Coastal Management (MCM) closed some key breeding localities to the competitive industrial fisheries. Post-doc Lorien Pichegru is monitoring intensively the impact of this closure on the success of the birds. This entails studying the foraging behaviour of breeding adults, by equipping them with GPS and depth recorders, and investigating their diet, their chicks' growth and body condition, and breeding success. The study compares the performance of penguins at St Croix (closed to fishing since 2009) and Bird Islands (open to fishing) in Nelson Mandela Bay. In the first year of closure, after only 3 months, the birds from St Croix reduced their foraging effort by 30%. We also investigate other aspects that could influence penguin population trends, such as the impact of Kelp Gull predation and the efficiency of artificial nests. Related studies include an assessment of the extent to which penguins use olfaction to find their prey and the impact of human disturbance on breeding penguins by recording their heart-rate in response to human activities. This is a collaborative project with MCM, and relies on the support of South African National Parks for permission to work at the islands in Nelson Mandela Bay.

At-sea behavioural responses of African Penguins Spheniscus demersus in relation to small-scale variability in prey distribution: implications for Marine Protected Areas

Research team: Alistair McInnes, Lorien Pichegru & Peter Ryan

This study will build on four years of existing data on African Penguin movements at two of the largest breeding colonies of this species in Algoa Bay, St Croix and Bird islands. The research is primarily aimed at determining the ecological processes that are responsible for the movements of these birds during their breeding season. It will also look at the impact of purse-sein fishery activity on the availability of prey for these birds and the implications of these and other anthropogenic impacts on the conservation status of this species.

Foraging ecology and conservation of Cape Gannets

Research team: David Grémillet, Lorien Pichegru, Rob Crawford & Peter Ryan

Like African Penguins, Cape Gannet Morus capensis population trends are linked to the availability of small pelagic fish (anchovies and sardines). For the past eight 8 years we have used GPS and depth loggers to study the foraging behaviour of gannets breeding on Malgas Island in relation to their diet and the distribution of their prey. During our study, their favoured prey of pelagic fish shifted away from the gannets' colony, forcing the birds to travel further in pursuit of their prey, until the fish moved effectively out of range, and the gannets switched to a diet of discards from hake trawlers. Unfortunately gannet chicks struggle to grow on such a lipid-low diet. In 2009, sardines returned to the west coast, and the gannets rapidly responded to this change. Monitoring the at-sea behaviour of Cape Gannets from Malgas Island helps us to understanding the responses of these birds to the variability in the distribution and abundance of their prey, and ultimately will help to inform the management of fisheries in the region, as required in terms of the Ecosystem Approach to Fisheries. This is a collaborative project with MCM, and relies on the support of South African National Parks for permission to work at Malgas Island.

Foraging ecology and conservation of southern African marine cormorants

Research team: Timothee Cook, Peter Ryan, Lorien Pichegru, Rob Crawford, Yan Ropert-Coudert & David Grémillet

Cape, Crowned and Bank Cormorants are endemic to the coasts of southern Africa. Although their status is cause for concern (near-threatened, near-threatened and endangered, respectively), little is known of their foraging ecology. Before considering a conservation plan for these species, it is important to understand their foraging strategies, in particular their spatial use of the marine environment and their diving behaviour and eco-physiology. This project characterises the foraging niches of southern African marine cormorants, using state-of the art electronic data-loggers (GPS and time-depth recorders), estimates of resource abundance, bird counts and satellite-derived physical oceanographic data. The study is longitudinal, as it compares the foraging ecology of birds from different colonies across several years, thus taking into account environmental variability. This project is based on an international collaboration and is funded locally by a Centre of Excellence post-doctoral fellowship (Department of Science and Technology/National Research Foundation) and a Claude Léon Foundation post-doctoral fellowship. Permission to work on cormorants at their breeding islands is granted by Cape Nature, South African National Parks and the Robben Island Museum.

Conservation genetics of southern African seabirds

Research team: Lisa Nupen, Peter Ryan & Jacqueline Bishop

The application of molecular techniques in the field of conservation provides a deeper understanding of the evolutionary patterns and processes that have produced the observed distributions of species. Conservation genetic studies also give insight into population connectivity and the distribution of genetic diversity within and between threatened populations over time and space. There are no baseline data on genetic diversity and patterns of gene flow between colonies of the threatened endemic seabirds that breed in the Benguela upwelling region. African Penguins, Cape Gannets and Cape Cormorants have undergone massive population declines since the early 1900s, but the genetic consequences of this are unknown. PhD student Lisa Nupen is collecting data on genetic diversity and investigating hypotheses relating to the evolutionary history of these species, patterns of dispersal, phylogeography, breeding site fidelity and mate choice. The results will provide novel insights regarding their responses to recent changes in the abundance and distribution of their preferred prey (sardines and anchovies) and hopefully give an indication of their adaptive abilities in the face of environmental change. This project would not be possible without funding from the Percy FitzPatrick Institute, the National Research Foundation (South African Biosystematics Initiative) and the University of Cape Town. The assistance and cooperation of SANParks, Cape Nature, the Namibian Ministry of Fisheries and Marine resources (MFMR) and SANCCOB also has proved invaluable.

Using stable isotopes to help conserve African seabirds

Research team: Viviane Barquete, Peter Ryan & Ross Wanless

Seabird biologists increasingly are using stable isotope (SI) markers, usually of carbon and nitrogen, to estimate the diet and movements of seabirds. Simplistically, the concentrations of heavy isotopes change as you move up food webs, and also vary regionally. By sampling blood and feathers of seabirds we can get some idea of their recent diet (blood) as well as their diet and location when they replaced their feathers (because feathers trap the SI signal of the bird when they are formed). PhD student Viviane Barquete is using SI data to test various hypotheses about the biology of both resident and migrant seabirds visiting southern African waters.

Estimating the impacts of longlining and trawling on southern African seabird populations

Research team: Peter Ryan, Bronwyn O'Connell, Samantha Petersen & Ross Wanless

Many seabirds are threatened as a result of interactions with fishing gear. Fisheries observers record the numbers of birds caught on South African longline and trawl fisheries, and carcasses of birds killed are returned to port for examination. We confirm the identity of birds killed, and age and sex them, to estimate the demographic impacts of these fisheries on seabirds. Analysing changes in catch rates gives a measure of the effectiveness of mitigation measures in reducing seabird mortality in these fisheries. This is a collaborative project with BirdLife International’s Albatross Task Force and WWF-SA.

Individual variation in reproductive output among albatrosses

Research Team: Genevieve Jones, Peter Ryan & Mareile Techow

This project attempts to understand the factors underpinning the marked reproductive skew among albatrosses. Despite having very conservative life history traits (delayed maturity and raising at most one chick per year), only a small proportion of breeding pairs are responsible for fledging the majority of chicks. PhD student Genevieve Jones is attempting to identify correlates of success, and to tease apart the relative importance of genetic and phenotypic quality through a series of cross-fostering experiments. The project builds on studies of colonies of individually marked Wandering Diomedea exulans and Grey-headed Albatrosses Thalassarche chrysostoma at Marion Island and Atlantic Yellow-nosed Albatrosses T. chlororhynchos at Gough Island. All three species are listed as threatened, mainly due to fishery mortality and the impacts of global change. A key component of the study is to assess sex allocation of chicks and to confirm paternity among pairs. We will test whether extra-pair fertilisations are the result of female choice or forced copulations. The project is funded by the Department of Environment Affairs and Tourism through the South African National Antarctic Programme, with additional support from the Fitztitute’s Centre of Excellence.

Tracking pelagic seabirds at sea

Research team: Peter Ryan, Richard Cuthbert, Richard Phillips, Rob Ronconi, Frances Taylor, Ross Wanless & Jacob Gonzales-Solis

Understanding where seabirds forage is crucial for managing the impacts of fisheries and marine pollutants on these birds, many of which are threatened species. We have deployed satellite transmitters and geolocator loggers onto a range of species breeding at islands in the African sector of the Southern Ocean, including Wandering and Grey-headed Albatrosses and Grey and White-chinned Petrels at Marion Island, Tristan, Yellow-nosed and Sooty Albatrosses, Southern Giant Petrels, Great Shearwaters and Subantarctic Skuas at Gough Island, and Yellow-nosed and Sooty Albatrosses, Great Shearwaters and Spectacled Petrels at Tristan da Cunha. The project is funded by numerous agencies, including BirdLife International and the NRF, and is supported the Department of Environment Affairs and Tourism through the South African National Antarctic Programme, with additional support from the Fitztitute’s Centre of Excellence.

The Conservation and Biology of the Damara Tern Sterna balaenarum in Namibia

Research Team: Justine Braby, Rob Simmons, Les Underhill, Jean-Paul Roux

This study was first initiated by the Namdeb Diamond Company, the ADU and the Fitz to look at the possible effects of diamond mining on the breeding productivity of the Damara Tern. Since then the thesis has been upgraded from an MSc to a PhD and is now a cross-section of the species. The Damara Tern is a globally Near-threatened seabird breeding along the desert coastline of Namibia, Angola and South Africa. The survival of the species is at risk due to increasing coastal development and off-road driving in Namibia. The thesis provides the first detailed information of breeding biology, demography and threats, re-assesses the global population, and makes recommendations for the conservation of the species. Justine's work has taken her to Nigeria, to survey migrant Damara Terns in their non-breeding grounds and to the Atacama Desert in Chile, to join a team or researchers on the study of the ecologically equivalent Peruvian Tern Sterna lorata.