Steffen Oppel - Past Projects

Feral cat control on St Helena (2011 - 2013)
The St Helena Plover is the only endemic bird species remaining on St Helena, and it is threatened by cat and rat predation. We examined whether removing feral cats would increase breeding success of St Helena Plovers in a large scale experiment in 2011-2013 where we controlled feral cats in two important breeding areas. Breeding success increased dramatically in semi-desert habitat, but very little in pastures, where removal of feral cats led to an increase in rat abundance. The St Helena Plover will require ongoing control of rats and feral cats.

Ecology of the Montserrat Oriole (2009 - 2014)
The Montserrat Oriole is endemic to a small island in the Caribbean, and critically endangered due to a variety of threats. We studied the effects of rainfall and volcanic ash on the survival and fecundity of Montserrat Orioles for >10 years to understand fluctuations in population size. Montserrat Orioles can produce more young in years with heavy rainfall, but suffer periodic population setbacks after volcanic ashfalls. We established an annual monitoring based on repeated point counts to document annual changes in population size. Between 2010 and 2014 the Montserrat Oriole population was stable.

Conservation of Aquatic Warblers in Europe and Africa (2009 - 2013)
The Aquatic Warbler nests in wet sedge marshes in eastern Europe and migrates to sub-Saharan West Africa. In collaboration with BirdLife partners and researchers from several range states we investigated whether habitat conditions on breeding grounds may be enhanced by large-scale habitat management such as mowing of sedge fens and bush removal. Mowing had a beneficial effect in the second year after mowing, mostly because it attracted a larger number of singing males and a higher nest density. We also established a robust monitoring programme to document the population trajectory of Aquatic Warblers in Biebrza national Park in Poland.

Feasibility of mammal eradication to protect seabirds in the Azores (2009 - 2013)
In collaboration with the BirdLife partner in Portugal (SPEA) we investigated causes of nest mortality of Cory's Shearwater on the island of Corvo. We also studied the movements and density of cats, rats, and mice on the island to assess the feasibility of predator eradication. The project established a small reserve protected by a predator proof fence to establish colonies of shearwaters and petrels, but concluded that rat and cat eradication is currently not feasible.

Comparing species distribution models for seabirds in the Atlantic (2010 - 2012)
Using a large shipboard survey database collected by the BirdLife partner in Portugal (SPEA) we investigated the performance of several spatial distribution modelling techniques to predict the distribution and abundance of Balearic Shearwaters in the east Atlantic Ocean. Predicting distribution was reliable, but predicting abundance was complicated and unreliable.

Assessing the utility of sound recorders to estimate nest density of nocturnal seabirds (2010 - 2013)
Many shearwaters breed on steep inaccessible cliffs, making it very difficult to estimate population sizes. Together with collaborators at the University of California Santa Cruz (USA) and Otago University (New Zealand) we developed an approach that used automated sound recording devices to predict the nest density of nocturnal burrow-nesting seabirds. This may be a useful long-term monitoring tool for many remote islands.

Yelkouan Shearwater conservation in Malta (2009 - 2011)
From 2009 through 2010 I assisted the LIFE project for Yelkouan Shearwaters run by BirdLife Malta. The project aimed to improve survival and breeding success of Yelkouan Shearwaters in Malta by land-based conservation measures. During the project many birds were ringed and we used mark-recapture techniques to estimate adult survival probabilities for Yelkouan Shearwaters. The results showed that survival has increased since the 1970s and 1980s when shearwaters were being illegally shot, but mortality at sea still appeared too high to sustain stable populations.

Seasonal interactions of King Eiders in Alaska (2005 - 2009)
My PhD research focussed on seasonal interactions of King Eiders migrating between breeding grounds in Alaska and wintering areas in the Bering Sea. Birds were tracked with satellite transmitters, and feathers, eggs, and food sources were collected to examine carry-over effects using stable isotope analysis. The results indicated a remarkable level of individual variation in King Eider migration patterns, winter movements, and breeding strategies. King Eiders nesting in Alaska were not capital breeders as previously expected, but used a variety of nutrient allocation strategies that heavily depended on local food sources of arctic breeding grounds for egg production.

Bird and dragonfly research in Papua New Guinea (2003 - 2004)
As a volunteer research assistant for the Wildlife Conservation Society I conducted research on the frugivorous bird assemblage of a keystone tree species in montane rainforest. The project revealed that a large number of pigeons and doves consumed the fruit that was previously believed to attract mostly birds of paradise. During the work in remote parts of Papua New Guinea I also studied the largely unknown dragonfly fauna in two areas, collected species previously unknown to science, and documented the changes in dragonfly communities as a result of forest alteration.

Conservation of the Pale-headed Brush-Finch in Ecuador (2002 - 2003)
The Pale-headed Brush-Finch was considered extinct for 50 years until a tiny remnant population was re-discovered in 1999. Together with the local BirdLife partner Fundacion Jocotoco I examined the habitat requirements and breeding success of the species, and identified the brood-parasitic Shiny Cowbird as a main threat to the species. After conservation management was implemented in 2003, the species has increased from ~50 birds in 2002 to >350 birds in 2009.

Restoration of Ulva Island, New Zealand (2000 - 2002)
New Zealand has pioneered the restoration of islands by removing introduced predators and re-introducing native species. I assisted the Department of Conservation to study the translocation success of endemic bird species Robin, Mohua, and Saddleback to Ulva Island. These species were brought to Ulva Island and established healthy breeding populations that quickly colonised the entire island. Unfortunately, rats managed to re-invade Ulva Island in 2010, requiring a new eradication effort.

Research and conservation in the Wadden Sea, Germany (1995 - 2002)
The German Waddensea is one of the most important staging areas for wetland birds. I worked for two non-profit conservation organisations, Schutzstation Wattenmeer and NABU, as national park warden for several years. I was involved in many research projects of waders (Sanderling, Dunlin, Red Knot, Avocet), geese (Brent and Barnacle Geese), and songbirds (Twite, Snow Bunting, and Shorelark), as well as regular censuses and monitoring of breeding and migratory birds. I conducted several small regional ornithological projects, provided breeding bird inventories of saltmarshes, peatlands, and wetlands, and participated in research projects at the Institute for Avian Research, studying the ecology of breeding Common Terns, and wintering songbirds in the Wadden Sea.

Bird ringing in Sweden (1997 - 1998)
To learn and practise mistnetting and ringing of passerines I volunteered for two months each summer at Annsjön Bird Observatory and Kvismaren Bird Observatory. I also participated in wader, waterbird, and crane censuses and breeding surveys in peatlands.

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