23 Result(s)
within
Peter G Ryan
Ecology
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Article
Open AccessFirst evidence of mouse predation killing adult great albatrosses
Invasive rodents threaten native species in numerous ecosystems, especially oceanic islands. The House Mouse Mus musculus is the only introduced mammal species on sub-Antarctic Gough and Marion Islands. Ample evi...
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Article
Cryptic speciation and population differentiation in the yellow-nosed albatross species complex
The two species of yellow-nosed albatross, Atlantic (Thalassarche chlororhynchos) and Indian (T. carteri), are morphologically similar, but they differ in breeding behaviour and distribution. Both species are lis...
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Article
Extent and symmetry of tail moult in Amur Falcons
Amur Falcons Falco amurensis undergo one of the most extreme migrations of any raptor, crossing the Indian Ocean between their Asian breeding grounds and non-breeding areas in southern Africa. Adults are thought ...
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Article
Open AccessA juvenile Tristan albatross (Diomedea dabbenena) on land at the Crozet Islands
Albatrosses and other seabirds are generally highly philopatric, returning to natal colonies when they achieve breeding age. This is not universal, however, and cases of extraordinary vagrancy are rare. The Tr...
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Open AccessShort-term movement patterns, population estimates and breeding biology of an island endemic bird, the Tristan Thrush
The Tristan Thrush Turdus eremita is the only land bird that survived human colonisation of the main island of Tristan da Cunha and is listed as “Near Threatened”. Population estimates are confounded by the thrus...
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Article
Plumage and bill abnormalities in albatross chicks on Marion Island
Accessible colonies of Grey-headed Albatross Thalassarche chrysostoma chicks on Marion Island have been inspected for chicks presenting mouse wounds from 2015, and during these inspections we found several cases ...
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Article
The effects of weather, group size and type of nest on the timing of egg-laying in the Southern Ground-hornbill Bucorvus leadbeateri
The timing of breeding in birds has important consequences if food availability varies seasonally. Optimal timing of the most energetically demanding stages of breeding to coincide with peaks in food availabil...
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Article
First evidence of mouse attacks on adult albatrosses and petrels breeding on sub-Antarctic Marion and Gough Islands
Invasive house mice Mus musculus are significant predators of seabird chicks on islands where they are the only introduced mammal, but there are very few records of attacks on adult birds. We report the first evi...
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Article
The foraging range of Great Shearwaters (Ardenna gravis) breeding on Gough Island
Ardenna shearwaters have among the most extreme foraging trips of any central place forager, yet little is known about the foraging range of the largest member of the genus, the Great Shearwater (Ardenna gravis)....
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Article
Status and trends of albatrosses in the French Southern Territories, Western Indian Ocean
Today albatrosses are threatened worldwide, especially by fishing activities, and many populations are currently in decline. Albatrosses breeding at the French Southern Territories in the south-western Indian ...
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Article
Westward range extension of Short-tailed Shearwaters Ardenna tenuirostris in the Southern Ocean
Short-tailed Shearwaters Ardenna tenuirostris are transequatorial migrants that breed at islands in southern Australia and spend the austral winter in the North Pacific. Adults feeding chicks undertake long forag...
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Article
Wandering Albatross Diomedea exulans breeding phenology at Marion Island
South Africa’s Prince Edward Islands support a large proportion (44 %) of the global Wandering Albatross Diomedea exulans breeding population, yet most breeding phenology data are recorded from smaller and geogra...
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Article
Modest increases in densities of burrow-nesting petrels following the removal of cats (Felis catus) from Marion Island
Introduced predators are one of the main threats facing seabirds breeding on oceanic islands. Cats (Felis catus) were introduced to subantarctic Marion Island (290 km2) in 1949, and by the 1970s some 2000 cats we...
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Article
Cranes and Crops: Investigating Farmer Tolerances toward Crop Damage by Threatened Blue Cranes (Anthropoides paradiseus) in the Western Cape, South Africa
The Western Cape population of Blue Cranes (Anthropoides paradiseus) in South Africa is of great importance as the largest population throughout its range. However, Blue Cranes are strongly associated with agricu...
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Article
The role of eddies in the diving behaviour of female southern elephant seals
As the Antarctic Circumpolar Current crosses the South-West Indian Ocean Ridge, it creates an extensive eddy field characterised by high sea level anomaly variability. We investigated the diving behaviour of f...
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The effect of parental age, experience and historical reproductive success on wandering albatross (Diomedea exulans) chick growth and survival
Growth and survival of altricial young are influenced by their parents’ abilities to invest in a breeding attempt. As a result, chick growth and survival in one breeding season may be indicative of their paren...
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Article
The occurrence of two bill morphs of prions Pachyptila vittata on Gough Island
Prions Pachyptila are abundant seabirds in the Southern Ocean that have been used to infer environmental change, but this relies on an understanding of their morphological diversity. Species limits among prions a...
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Giant petrels as predators of albatross chicks
Giant petrels Macronectes spp. are not thought to be important predators of albatross chicks, although they are known to kill pre-fledging Thalassarche and Phoebetria albatrosses. We report the first records of p...
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Article
Diving patterns of female macaroni penguins breeding on Marion Island, South Africa
Despite the large biomass of macaroni penguins Eudyptes chrysolophus in the Southern Ocean, their feeding ecology is poorly known at some important breeding localities. We investigated the diving behaviour and di...
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Molecular provenance analysis for shy and white-capped albatrosses killed by fisheries interactions in Australia, New Zealand, and South Africa
Shy and white-capped albatrosses, Thalassarche cauta and T. steadi, respectively, are phenotypically similar and are known to suffer fisheries-related bycatch mortality across their foraging range. Assessments of...
