Bird ringing in Britain and Ireland in 2000

Although Rose-ringed Parakeets Psittacula krameri over three years old can easily be sexed due to the males' rose-coloured neck-rings and black bibs, sexually immature males and females are considered impossible to separate in the hand. The biometrics of males and females overlap but males tend to be slightly larger than females in all measurements. We derived a discriminant function to separate the two sexes using wing length, bill length and the number of fully yellow underwing coverts. Biometrics were recorded for 235 individuals captured between February 2001 and May 2003. Feather and blood samples were taken from 45 of these birds to determine the sex by haplotyping. The measurements from these known-sex individuals (22 females and 23 males) were pooled with the measurements for adult males and a binary logistic regression function was derived which correctly separated 96.6% of the known sexes. The first data on moult patterns in Britain were obtained and are useful in ageing birds during the spring. In addition, it was found that the tips of primaries were rounder in adult birds than in juveniles, a result that agrees with other studies on parrots and some other bird species.

Section: Discussionmentioning

confidence: 76%

“…When ageing Rose-ringed Parakeets, only one fact is known for certain: adult males have a rose-coloured ring Up to the end of 2000, a total of 42 Rose-ringed Parakeets Psittacula krameri had been ringed in Britain (Clark et al 2002). However, accurate identification of age and sex classes of Rose-ringed Parakeets is a problem.…”

mentioning

confidence: 99%

Sexing and ageing Rose‐ringed ParakeetsPsittacula krameriin Britain

Butler

Gosler

2004

“…In total, approximately 4,600 Turtle Doves have been caught and ringed in Britain and Ireland between 1956 and 2000 (Clark et al 2002). Unfortunately our appeal to current members of the ringing scheme, the Bird Observatories and the BTO yielded biometric data from only 589 Turtle Doves, 13% of those that have been caught.…”

Section: Discussionmentioning

confidence: 99%

Temporal variation in the biometrics of Turtle DovesStreptopelia turturcaught in Britain between 1956 and 2000

Browne¹,

Aebischer²

2003

We analysed biometric data collected from 589 Turtle Doves Streptopelia turtur measured between 1956 and 2000 in Britain. Male wing length was on average 4 mm longer than females, which were on average 8 mm longer than juveniles. Wing length increased by approximately 5 mm over the period 1956 to 2000, probably owing to differences in measuring techniques over the years. Males were heavier than females by about 5 g, and females were in turn 10 g heavier than juveniles. Turtle Dove body weight varied with season, with birds being heavier by about 10 g in autumn. Using the ratio of wing length to body weight to represent body condition, we found no annual variation in body condition, but body condition was lowest in spring and highest in autumn. Because we were unable to detect a change in average body condition over time, the hypothesis that lowered body condition caused reduced breeding productivity in the 1990s is unsubstantiated.

Bird ringing in Britain and Ireland in 2001

Clark

Balmer

Adams

et al. 2002

Self Cite

This is the 65th annual report of the British Trust for Ornithology's Ringing Scheme covering work carried out and data received in 2001. As part of the BTO's production of the landmark Migration Atlas: movements of the birds of Britain & Ireland, which will review movements of birds using Britain & Ireland, novel approaches to the investigation of the movement patterns and distances were developed. These allow the objective comparison of whether different species are sedentary, short-distance or long-distance migrants and the investigation of differential migration between birds of different age and sex. The BTO continues to carry out a programme of work investigating the declines in bird populations. In 2001, an investigation of Song Thrush population dynamics showed that the survival rates of young birds was key in the population decline; reduction in survival rates also seemed to have driven the fall in numbers of Marsh Tits. Work on movements of waders between roosts on the Moray Basin showed little movement for most species; important information when the possible effects of disturbance are being considered. An investigation of the biometrics of the Redshank wintering on Severn Estuary found that the proportions of Icelandic and British breeders varied between sites; again an important factor in assessing the possible consequences of disturbance. A pilot project, which is investigating the collection of data on movements and demography of farmland passerines in winter is described. Data collected as part of the Constant Effort Sites (CES) Scheme showed significant changes in the numbers of seven species between 2000 and 2001. Of these, five resident species (Blackbird, Blue Tit, Great Tit, Chaffinch and Greenfinch) and one migrant (Whitethroat) showed increases. Only one species (Willow Warbler) decreased. By contrast, productivity tended to be low with 11 species, both residents (Dunnock, Robin, Blackbird, Long-tailed Tit, Blue Tit, Greenfinch and Reed Bunting) and migrants (Sedge Warbler, Reed Warbler, Blackcap and Chiffchaff) showing significant declines. Progress on the EURO-CES project, which aims to develop standard protocols for CES fieldwork and data capture across Europe is reported. Data sets for 86 studies of 42 species were submitted as part of the Retrapping Adults for Survival (RAS) Project. The first detailed analysis of Pied Flycatcher data from RAS-type studies showed that survival rates vary between different areas of the country and confirms the value of this project. The numbers of birds ringed in 2001 (648,936) was 16% below the mean of the previous five years (1996)(1997)(1998)(1999)(2000), largely as a result of Foot and Mouth Disease, which restricted the areas ringers had access to. The recovery total (10,692) was 6% lower than the five-year mean (1996)(1997)(1998)(1999)(2000). Recoveries of 195 BTO-ringed birds and 77 birds ringed abroad are presented in the report and include a number of unusual or significant movements. Of particular note are the first recovery of a Great White E...