GREAT news in the run-up to Easter – a fourth egg in the peregrine nest on Salisbury Cathedral.
The cathedral authorities think the peregrine female may now be incubating – this doesn’t start until the last egg is laid, but given that a normal clutch is three or four, they are pretty certain she has started.
Incubating takes around 29-30 days, which would mean chicks in early May. When a female incubates she uses a special bare area on her underside that is rich in blood supply (called the brood patch) to warm the eggs. If you watch her (via the cathedral’s peregrin-cam) she regularly shifts position to give each egg time next to the brood patch.
The first egg was laid on 22nd March, the second on the 25th, the third on the 27th and the fourth on the 29th.
Salisbury Cathedral has an historic bond with peregrines. There were nine fully authenticated sightings between 1864 and 1953, details of which are held in the Wiltshire archive. They disappeared from the tower in 1953 returning in 2014 when a pair bred successful on the south side tower balcony. Three peregrine chicks were hatched, ringed and fledged from the base of the spire that year.
In 2014, three chicks hatched, in 2015 there were four, in 2016, two hatched and both died, and in 2017 thee was one chick that was joined by an orphaned chick. There were no chicks in 2018 after the resident peregrine held her territory but lost her mate. No-one knows where he is or if he is alive. Last year there was a new pair, and there were four chicks.
All chicks are ringed with a distinctive wide blue leg ring that denotes they are a peregrine ringed in the south west. If people are out walking and spot a peregrine, look for the ring initials and let the cathedral know – www.salisburycathedral.org.uk