Breeding performance of Ring-necked ParakeetsPsittacula krameriin small introduced populations in southeast England

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

“…Although second clutches have been reported in other populations (Hossain et al 1993), no second clutches were found over the course of this study. Mean clutch size (3.7 ± 1.2 eggs) during this study was similar to the mean clutch size reported elsewhere (Lamba 1966, Simwat & Sidhu 1973, Shivanarayan et al 1981, Hossain et al 1993, Pithon & Dytham 1999a). The estimate of 1.4 young fledged per nest during 2001-2003 was comparable to that found in Bangladesh and southern India (Shivanarayan et al 1981, Hossain et al 1993, but considerably lower than that reported elsewhere in India (Lamba 1966).…”

“…The estimate of 1.4 young fledged per nest during 2001-2003 was comparable to that found in Bangladesh and southern India (Shivanarayan et al 1981, Hossain et al 1993, but considerably lower than that reported elsewhere in India (Lamba 1966). The estimate of 1.4 young fledged per nest during [2001][2002][2003] was nearly twice the 0.8 birds fledged per nest (in the UK) reported previously (Pithon and Dytham 1999a). It is not clear whether reproductive output in the UK had increased during the years of our study or whether the low estimate by Pithon and Dytham (1999a) was a consequence of the small sample size (n = 12).…”

“…The estimate of 1.4 young fledged per nest during [2001][2002][2003] was nearly twice the 0.8 birds fledged per nest (in the UK) reported previously (Pithon and Dytham 1999a). It is not clear whether reproductive output in the UK had increased during the years of our study or whether the low estimate by Pithon and Dytham (1999a) was a consequence of the small sample size (n = 12). It has been noted however, that reproductive output may be density-dependent in some introduced species, with low reproductive output at low densities (i.e.…”

“…In contrast, only 0.6% of nestboxes were used (one out of 175) in the Greater London area during 1998 (Pithon and Dytham 1999a). Nestbox design and positioning was similar in the two studies which suggests that suitable nesting sites may be a limiting factor for parakeets breeding at the Isle of Thanet, but not for parakeets breeding in the Greater London area.…”

“…In addition, 34 nestboxes were placed in six public areas on the Isle of Thanet during June and July of 2002. The nestboxes were based on the same measurements as those in a previous study in 1997 (Pithon and Dytham 1999a). As per the Pithon and Dytham (1999a) study, nestboxes were placed approximately eight metres above the ground.…”