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Article
Simon Foster, Auteur ; Ron W. Summers, Auteur ; R.L. (Bob) Swann, Auteur ; Tanya Scott, Auteur ; Les G. Underhill, AuteurEurasian Curlews Numenius arquata arquata which moult and winter in the Moray Firth, northern Scotland, had a mean start date of 24 June (95% range 18 May to 31 July) for primary moult, which then took a mean of 122 days, giving a mean completio[...]
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R.L. Swann, Auteur ; Ron W. Summers, Auteur ; Tanya Scott, Auteur ; Les G. Underhill, AuteurThe timing and duration of primary moult of Eurasian Oystercatchers Haematopus ostralegus that carry out post-nuptial moult and spend the winter in the Moray Firth, northern Scotland, varied according to their age and sex. There was also a long-[...]
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Itxaso Quintana, Auteur ; Salome Willemse, Auteur ; Karis Daniel, Auteur ; Trevor Hardaker, Auteur ; Les G. Underhill, AuteurData from five citizen science projects were used to document shifting ranges of two species of bulbul in South Africa. We show that African Red-eyed Bulbuls Pycnonotus nigricans steadily replaced Cape Bulbuls P. capensis in the lower Olifants R[...]
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Les G. Underhill, Auteur ; Tanya Scott, AuteurThe Underhill–Zucchini model of avian moult is a statistical simplification for the analysis of primary moult, a complex biological system in birds. As with all such models, conclusions can be biased if a subset of the data used to fit the model[...]
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Tanya Scott, Auteur ; Les G. Underhill, Auteur ; George D. Underhill, AuteurA new moult index, the relative duration index (RDI), was developed to quantify progress through moult using the Underhill–Zucchini model of primary avian moult, with the Laughing Dove Spilopelia senegalensis as a case study. The RDI weights ind[...]
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Taylyn C. Bate, Auteur ; Peter G. Ryan, Auteur ; Les G. Underhill, AuteurAfrican Oystercatchers Haematopus moquini are sedentary, intertidal foraging birds, range-restricted to Namibia and South Africa. Their annual cycle has two components: breeding and moult. The Underhill– Zucchini model estimated a primary moult [...]
Article
Magdalena Remisiewicz, Auteur ; Zephné Bernitz, Auteur ; Herman Bernitz, Auteur ; Marc S. Burman, Auteur ; Jacobus M. H. Raijmakers, Auteur ; Johannes H. F. A. Raijmakers, Auteur ; Les G. Underhill, Auteur ; Anna Rostkowska, Auteur ; Yahkat Barshep, Auteur ; Sergej A. Soloviev, Auteur ; Ilona Siwek, AuteurDans Ibis (161(4) 2019)Trade-offs between moult and fuelling in migrant birds vary with migration distance and the environmental conditions they encounter. We compared wing moult and fuelling at the northern and southern ends of migration in two populations of adult C[...]
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Magdalena Remisiewicz, Auteur ; Anthony J. Tree, Auteur ; Les G. Underhill, Auteur ; Marc S. Burman, AuteurTrans-equatorial avian migrants tend to breed, moult and migrate – the main energy-requiring events in their lifecycle – at different times. Little is known about the relationship between wing moult and pre-migratory fuelling in waders on their [...]
Article
Magdalena Remisiewicz, Auteur ; Anthony J. Tree, Auteur ; Les G. Underhill, Auteur ; Jaroslaw K. Nowakowski, AuteurGreenshanks Tringa nebularia show various patterns of primary moult in the northern hemisphere, but farther south moult patterns are known only fragmentarily. We identified geographical patterns in primary moult and pre-migratory fattening of Gr[...]
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Yahkat Barshep, Auteur ; Les G. Underhill, Auteur ; S. Balachandran, Auteur ; David J. Pearson, AuteurWe investigated the adaptations of primary moult to conditions on the non-breeding areas in the Curlew Sandpiper Calidris ferruginea, an Arctic breeding, long-distance migratory wader (shorebird). Parameters of moult (start date, duration, and s[...]
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Res Altwegg, Auteur ; Les G. Underhill, AuteurReliable estimates of survival rates of southern African bird species are still rare. Yet precise information on life history traits of birds from this southern Mediterranean-type climate would help in evaluating the generality of global pattern[...]
Article
Azwianewi B. Makhado, Auteur ; Robert J. M. Crawford, Auteur ; Lauren J. Waller, Auteur ; Les G. Underhill, AuteurDans Ostrich (84(3) 2013)At Dyer Island, South Africa, observations of predation of seabirds by Cape Fur Seals Arctocephalus pusillus pusillus were made during 2004 and 2006/07. It was estimated that seals killed about 7% of adult African Penguins Spheniscus demersus an[...]
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Les G. Underhill, Auteur ; Jan H. Hofmeyr, AuteurRooikrans Acacia cyclops is an invasive plant species in the coastal region of South Africa, especially the Fynbos Biome. It is endemic to southwestern Australia. Seeds are bird-dispersed, mostly by frugivores and granivores. We report that at o[...]
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H. Dieter Schadleus, Auteur ; Les G. Underhill, AuteurThe grassland biome in South Africa has a summer rainfall and Southern Red Bishops Euplectes orix, Fan-tailed Widows E. axillaris, White-winged Widow E. albonotatus, Red-collared Widow E. ardens and Long-tailed Widow E. progne breed from October[...]
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Kathy M. Calf, Auteur ; G. Henk Visser, Auteur ; Les G. Underhill, Auteur
Article
Ron W. Summers, Auteur ; Les G. Underhill, Auteur ; Manfred Waltner, Auteur ; Robert L. Swann, AuteurWe describe the migration, biometrics and moult of Red Knot Calidris canutus canutus in southern Africa and compare them with the biometrics and moult of Calidris canutus islandica in northern Europe to examine possible adaptations to different [...]
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Les G. Underhill, Auteur
Article
Shannon L. Hampton, Auteur ; Peter G. Ryan, Auteur ; Les G. Underhill, AuteurConcerns have been expressed over the impact of flipper banding on the survival and reproductive performance of penguins. This study compared the breeding success of banded and unbanded African Penguins Spheniscus demersus at Boulders Beach, Sou[...]
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Peter J. Barham, Auteur ; Les G. Underhill, Auteur ; Robert J. M. Crawford, Auteur ; Res Altwegg, Auteur ; T. Mario Leshoro, Auteur ; Duncan A. Bolton, Auteur ; Bruce M. Dyer, Auteur ; Leshia Upfold, AuteurSome 2,000 orphaned chicks of African Penguins Spheniscus demersus were hand-reared and released back into the wild on Robben and Dassen Islands following the Treasure oil spill in June 2000. Of these chicks, 1,787 were flipper banded. This pape[...]
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Les G. Underhill, Auteur ; G. Henk Visser, Auteur
Article
Magdalena Remisiewicz, Auteur ; Anthony J. Tree, Auteur ; Les G. Underhill, Auteur ; Anna Gustowska, Auteur ; P. Barry Taylor, AuteurMigrant waders using freshwater habitats are hypothesized to have slower primary moult than waders using coastal habitats. We chose the Wood Sandpiper Tringa glareola as a representative species using the freshwater habitats and compare its moul[...]
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Les G. Underhill, Auteur ; Philip A. Whittington, Auteur ; Robert J. M. Crawford, Auteur ; Anton C. Wolfaardt, AuteurThe world population of the African Penguin (Spheniscus demersus), a vulnerable species confined to South Africa and Namibia, is estimated to be 180 000 birds; 10 000 were oiled in the "Apollo Sea" spill in June 1994. Of the 5000 penguins that s[...]
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Res Altwegg, Auteur ; Robert J. M. Crawford, Auteur ; Les G. Underhill, Auteur ; A. Paul Martin, Auteur ; Philip A. Whittington, AuteurDifferent populations of a species tend to vary in survival and reproduction, but the extent and scale of such spatial variation are poorly known. We estimated survival and clutch size of kelp gulls Larus dominicanus vetula across their entire A[...]
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Albert Schultz, Auteur ; Les G. Underhill, Auteur ; Roy A. Earle, Auteur ; George Underhill, AuteurOver a two-year period, 945 adult Cape Weavers Ploceus capensis were mist-netted with a bias towards 632 male and 308 female birds. Blood smears presented avian haemosporidia in 58.79% of males and 61.90% of females, representing five species fr[...]
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Robert J. M. Crawford, Auteur ; Peter J. Barham, Auteur ; Les G. Underhill, Auteur ; Lynne J. Shannon, Auteur ; Janet C. Coetzee, Auteur ; Bruce M. Dyer, Auteur ; T. Mario Leshoro, Auteur ; Leshia Upfold, AuteurFrom 1989 to 2004, the breeding success of African penguins Spheniscus demersus at Robben Island, South Africa was significantly related to estimates of the abundance of both their main prey species, anchovy Engraulis encrasicolus and sardine Sa[...]
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Les G. Underhill, Auteur ; Richard B. Sherley, Auteur ; Bruce M. Dyer, Auteur ; Robert J. M. Crawford, Auteur
Article
Res Altwegg, Auteur ; Robert J. M. Crawford, Auteur ; Les G. Underhill, Auteur ; A. Williams, AuteurAfter oil spills, oiled wildlife are regularly cleaned at considerable cost. Yet the conservation value of this intervention has been questioned, mostly because cleaned animals appear to have poor post-release survival. However, reliable long-te[...]
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Anne Voorbergen, Auteur ; Willem F. de Boer, Auteur ; Les G. Underhill, AuteurTo develop conservation strategies for vulnerable seabird species that need attention, it is important to know which factors influence their breeding productivity. Predation of eggs and chicks can have large influences on seabird reproduction, e[...]
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Yahkat Barshep, Auteur ; Clive Minton, Auteur ; Les G. Underhill, Auteur ; Magdalena Remisiewicz, AuteurThe population moult parameters, yearly onset of moult and sex-specific schedule of moult in relation to breeding success, and pattern of feather mass growth were examined in a population of Curlew Sandpipers Calidris ferruginea that migrate to [...]
Article
Magdalena Remisiewicz, Auteur ; Anthony J. Tree, Auteur ; Les G. Underhill, Auteur ; P. Barry Taylor, AuteurImmature migrant waders have more complex patterns of primary moult than adults, but these have been described only fragmentarily. The Wood Sandpiper Tringa glareola breeds in the taiga region of the Palearctic and part of the population migrate[...]
