Sexing and ageing Rose‐ringed ParakeetsPsittacula krameriin Britain

Abstract

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.

Biology and Impacts of Pacific Island Invasive Species. 15. Psittacula krameri, the Rose-Ringed Parakeet (Psittaciformes: Psittacidae)

“…Psittacula k. manillensis is a 38-42 cm long (body + tail) parrot, with its tail accounting for about half of its length (∼25 cm; Butler 2005). In Europe, adult RRP generally weigh about 140 g (Butler and Gosler 2004). RRP on Kaua'i averaged 133 g, but 12 of the 17 individuals weighed were juveniles; the four adult males averaged 139 g (Gaudioso et al 2012).…”

The breeding biology of Rose-ringed ParakeetsPsittacula krameriin England during a period of rapid population expansion

“…However, without carefully examining Rose-ringed Parakeets in the hand, it is not possible to separate sub-adult males from adult females (Butler & Gosler 2004) and so it is possible that multiple females were attending the nests. However, an examination of the Rose-ringed Parakeet specimens at the Natural History Museum, Tring reveals that there is a sub-adult specimen with a slightly enlarged testis, which may indicate that subadult male Rose-ringed Parakeets occasionally breed.…”

Invasive birds: global trends and impacts

“…The subspecies P. k. parvirostris, which ranges from parts of Sudan east through northern Ethiopia and north-west Somalia, is similar but has a smaller beak and a somewhat greener, less yellowish head and cheeks (Ali and Ripley, 1969;Forshaw, 1978Forshaw, , 2010Fry and Keith, 1988). Butler and Gosler (2004) found that for Ring-necked Parakeets in the UK, female birds were characterized by a higher number of yellow underwing coverts, while juveniles could reliably be identified on the basis of their more pointed primary feathers.…”