Six weeks on from the fledging of the juvs, the new colour rings are proving their value, allowing easy identification of their coming and goings.
The pictures above show the ringing on May 18th, the three juvs ringed with silver BTO rings and the orange plastic rings labelled PRF, PSF and PTF respectively. Since they fledged, there have been various sightings of PRF and PTF, but none reported of PSF.
Both PRF and PTF have continued to visit the nest platform at St George’s on a regular basis, roosting there quite often and receiving food drops from one or other of the parents, which seem to be fully tolerant of their presence. On the basis of some of the other urban sites monitored by webcams, this is not typical, and does not follow the pattern of previous years in Sheffield, where the juvs have dispersed from St George’s within a few weeks of fledging.
When the chicks were ringed, PSF was a little smaller than its two siblings, in wing length as in tarsus length. With no subsequent confirmed sightings, it may be that it has succumbed to illness or infection, or perhaps it has move further afield: fingers crossed for the latter, although mortality rates are high, at around 60-70% in the first year. About half of those that do not survive are thought to die from infectious disease, parasitism or other organic diseases. Known causes of death include trichomoniasis (better known for killing large numbers of Greenfinches and other finches), botulism and myiasis (fly maggot infestation).
On a happier note, an early morning visit to St George’s revealed the male and PTF to be present. They were content to sit unmoved, even when a couple of Feral Pigeons decided to land either side of the nest platform.
One of them then took off and flew right in front of the male, landing on the turret opposite. Even then he showed no sign of action beyond an interested stare.
So two of the Sheffield juvs are doing well, and if anyone has any sightings of PSF (as well as of PRF and PTF) do please share them, either via the twitter feed or by e-mail to firstname.lastname@example.org