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Haslemere, United Kingdom

Feare C.J.,WildWings Bird Management | Dietrich M.,University of Reunion Island | Dietrich M.,University of Pretoria | Lebarbenchon C.,University of Reunion Island
Marine Ornithology | Year: 2015

On Bird Island, Seychelles, adult Sooty Terns are frequently found injured on the beach, usually with dislocated or broken wings, during the breeding season. By ruling out other possibilities we hypothesized that the injuries were caused by frigatebirds, and therefore predicted that (1) most attacks would take place in the late afternoon, when adult Sooty Terns normally return to the colony after feeding during the day; (2) most injuries would be inflicted during the late afternoon and so injured birds are most likely to be found on the beach the following morning, after they have swum ashore; and (3) frigatebird Fregata spp. attacks would be more frequent during chick rearing, when adults carry fish and/or squid for their chicks, than during incubation, when they carry only the food required for their own maintenance. At twoweek intervals during the 2014 breeding season we undertook early morning and late evening 5-d surveys of the number of beached Sooty Terns, of frigatebirds chasing seabirds visible from the beach, and of frigatebirds in the communal roost. The first two predictions were supported by the data but the third was not; this failure was considered to be due to frigatebirds parasitizing other species, especially Lesser Noddies Anous tenuirostris, when these were more profitable sources of regurgitates. Overall, we conclude that frigatebirds are responsible for the injuries that cause Sooty Terns to be found on the beach, and that the number found on the beach is probably only a small proportion of the mortality inflicted on the Bird Island colony. © 2015, Marine Ornithology. All rights reserved.

Feare C.J.,WildWings Bird Management
Marine Ornithology | Year: 2014

This study investigated the mechanism by which some Sooty Terns, which lay one egg, are found with two eggs in a nest. Trials in which eggs were placed at different distances from existing nests showed that eggs laid close to nests were sometimes adopted by the nest owner, the probability of adoption depending on the proximity of the new egg to the nest. Eggs placed further from existing nests were unlikely to be adopted and more likely to disappear, probably through predation. The adoption of second eggs appears to lead to prolonged incubation and compromises the success of the host's own breeding attempt. Eggs that have been adopted to form two-egg clutches appear to have been laid accidentally, but why this happens is not known.

This paper reviews outbreaks of Asian-lineage highly pathogenic avian influenza virus (HPAIV) H5N1 in wild birds since June 2006, surveillance strategies, and research on virus epidemiology in wild birds to summarize advances in understanding the role of wild birds in the spread of HPAIV H5N1 and the risk that infected wild birds pose for the poultry industry and for public health. Surveillance of apparently healthy wild birds ("active" surveillance) has not provided early warning of likely infection for the poultry industry, whereas searches for and reports of dead birds ("passive" surveillance) have provided evidence of environmental presence of the virus, but not necessarily its source. Most outbreaks in wild birds have occurred during periods when they are experiencing environmental, physiologic, and possibly psychological stress, including adverse winter weather and molt, but not, apparently, long-distance migration. Examination of carcasses of infected birds and experimental challenge with strains of HPAIV H5N1 have provided insight into the course of infection, the extent of virus shedding, and the relative importance of cloacal vs. oropharyngeal excretion. Satellite telemetry of migrating birds is now providing data on the routes taken by individual birds, their speed of migration, and the duration of stopovers. It is still not clear how virus shedding during the apparently clinically silent phase of infection relates to the distance travelled by infected birds. Mounting an immune response and undertaking strenuous exercise associated with long migratory flights may be competitive. This is an area where further research should be directed in order to discover whether wild birds infected with HPAIV H5N1 are able or willing to embark on migration. © 2010 American Association of Avian Pathologists.

Feare C.J.,WildWings Bird Management
Ringing and Migration | Year: 2011

Coloured Darvic rings fitted to Sooty Terns in the Seychelles became brittle and fell off. Where birds had been ringed also with Incoloy BTO rings, the extent of loss was quantified. Darvic rings are unsuitable for long-term studies of Seychelles Sooty Terns and may be unsuitable for long-term population studies of other tropical seabirds. © 2011 British Trust for Ornithology.

Feare C.J.,WildWings Bird Management | Doherty Jr. P.F.,Colorado State University
Marine Ornithology | Year: 2011

Age at first breeding and annual survival between fledging and first breeding were estimated from band recapture data, taking into account resighting probability, collected in a large colony of Sooty Terns Onychoprion fuscatus nesting on Bird Island, Seychelles. The model of age at first attempted breeding probability indicated that most young birds first bred when 5 years old, conforming with earlier estimates from other colonies. Annual survival between fledging and first attempted breeding was estimated for the first time for Sooty Terns, as 0.77, giving a probability of young birds surviving to breed at age 5 of 0.26. Implications of these findings for the exploitation of eggs from Seychelles Sooty Tern colonies are discussed.

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