Unfortunately, one of this year’s young peregrines died earlier this week following a collision with a building. The female PCA was found near Sainsburys, Ings Road and was cared for by Jean Thorpe, of Ryedale Wildlife Rehabilitation.
PCA being X-rayed
PCA was examined by Mark Naguib, a vet who has lots of experience in dealing with raptors. Mark found that the bird had dislocated an elbow joint at least 24 hours earlier. He tried to put the bones back into place but this proved to be impossible and the decision was taken to end the bird’s life whilst it was still under the anaesthetic.
The decision was not an easy one but it was based on the fact that peregrines rely so heavily on the use of their wings to hunt their prey. PCA would never again have been able to live freely and to hunt as a peregrine should.
Dislocated elbow joint
We are grateful to Jean and Mark for the time and effort that they have given to caring for PCA.
It’s always sad to hear of the death of a peregrine but we must stand back and look at the whole picture. The Wakefield peregrines have now fledged ten young. We know of four deaths, all caused by collisions, and this means that there are, potentially, six new peregrines out there somewhere. If fifty percent of young peregrines survive the first year, that should be considered to be a good result. In their lifetimes, our two adults need to produce only two new peregrines that go on to breed successfully to replace themselves. I think there is a good chance that they have succeeded in that task.
A big event on the peregrine calendar is the ringing of the peregrine chicks. This year’s ringing took place on Saturday, 27th May, when the youngsters were three weeks and four days old.
The youngsters were collected from the nestbox and ringing was carried out inside the spire, out of sight of the parents. This was done by members of the Sorby Breck Ringing Group. The ringers are licensed to ring birds such as peregrines, which are given special protection as “Schedule 1” birds.
Ringing a peregrine
The young birds were fitted with metal BTO (British Trust for Ornithology) rings. This type of ring carries a number which can be reported to the Natural History Museum if a bird is found dead or injured. Each peregrine was also given a plastic ring carrying just three letters. These letters can be read on live birds using binoculars or telescopes. The plastic rings provide the opportunity for receiving information about the movements of the peregrines in the future. The three rings used were orange and carried the letters PAA, PBA and PCA. PAA and PCA are females, whilst PBA is a male.
Taking measurements of a peregrine chick
The chicks were weighed and this was the key to deciding the sex of each youngster. Females are larger than males and the largest of the Wakefield chicks weighed 1.1 kg. The smallest chick, the male, weighed only 750g. As you can see form the picture, other measurements were taken.
Barn owl chick
Whilst they were in the area, the ringers arranged to ring four barn owl chicks which are growing well in a nestbox maintained by Danny Kirmond.
Little owl chicks
Danny also has a little owl box containing a brood of young little owls. The ringers were able to ring those. When they went to do this, they found an adult in the box, so they took the opportunity to ring that too.
Adult little owl
It was quite a productive day for the ringers and we are grateful to them for taking the time to deal with our peregrines.
The peregrines on Wakefield Cathedral have been incubating four eggs for almost five weeks. The first hatching was expected on Tuesday, 2nd May, 34 days after the laying of the third egg.
On Tuesday afternoon, it was clear that something was happening because the female fidgeted a lot and looked down towards the eggs frequently. She also refused to take anything when the male tried, several times, to make a food delivery. Eventually, she shifted position and we could see that at least one egg was hatching.
First Sighting of a Chick
Our first sighting of a chick came later on Tuesday evening, when the female left the chick and eggs briefly to relieve herself by reversing up to the edge of the nestbox. Judging by internet comments, a lots of people, including at least one in Australia, were glued to their screens as they waited to see how many eggs would hatch. For peregrines, it’s normal for most of the eggs to hatch almost simultaneously, whilst the remaining egg hatches a couple of days later.
It was the following morning when we saw that three eggs had hatched. The female fed the chicks and then, for the first time, allowed the male to go near them so that he could sit on them whilst she took a short break.
Unfortunately, one egg was damaged at some point during the incubation period. The damage was first noticed a few days before the hatching. It looks like a puncture caused by a talon. In the picture, you can see that the female has relaxed the toes of her left foot so that they curl up. This is what the birds do instinctively as they approach the eggs to avoid causing damage. However, accidents do happen and it isn’t unusual for an egg to be damaged. As three chicks hatched together, the damaged egg must have been the last one to be laid.
This year’s clutch was completed with the laying of a fourth egg just after 3 a.m. on 1st April. The birds have, therefore, been incubating for a little over two weeks and they are well into their usual routine. The female incubates throughout the night and the male takes over for an hour or two early in the day. He usually returns to do another shift – often lasting 2 to 4 hours – in the afternoon.
Peregrines begin incubation with the laying of the penultimate egg, which was on Wednesday, 29th March. Last year, the first hatching was 34 days after the laying of the third egg. Using this as a guide, I would expect the first hatching this year to be on Tuesday, 2nd May. Factors such as the outside temperature can affect incubation time, so this date is only a guide and hatching could begin a day or two either side of this date.
The first three eggs should hatch very close to each other and the fourth egg should hatch a couple of days later.
The peregrines remained on the cathedral throughout the winter, holding onto their nest site and chasing away intruders regularly. They have spent recent weeks preparing to breed by carrying out ledge displays and making a nest scrape.
First sighting of the new egg.
Last year’s first egg appeared in the early hours of the 25th March and the female has been remarkably true to this day by laying her first egg of 2017 late on 24th March, not long before midnight.
A watcher in Texas saw when the egg was fully uncovered for the first time and I wonder how many other people were watching in countries around the world.
It was daylight when the male got his first look at the egg but the female soon arrived to keep her eye on it.
We expect eggs to be laid every two and a half days, approximately, until there is a clutch of three or four. The female will start to incubate when the penultimate egg has been laid.
The young peregrines are now roaming quite freely and there was a report, two days ago, of a juvenile seen chasing a black-headed gull at Wintersett, This could well have been a Wakefield bird. Although the juveniles are spending increasing lengths of time away from the cathedral it is still possible to see them, with a little patience.
Visitors to Wakefield showing a keen interst in the peregrines.
A group of Chinese visitors joined me for a while yesterday as I spent an hour or two seeing how many I could locate. It was quiet for a while but 5Z visited the nestbox. I have found, when I have reviewed recorded footage, that 5Z is the one youngster that does this regularly. It usually searches the box for scraps of the food but during yesterday’s visit, it was clear that it had just fed because its crop was bulging and there was blood on one of its feet.
5Z visiting the nestbox.
3Z also dropped in but it chose to sit high on the spire. It was obviously on the lookout for food because it searched the larder on the north side of the spire and kept gazing up at the female parent expectantly.
3Z sitting high on the spire.
Arriving in Wakefield shortly after 5 a.m., I was just in time to see the female peregrine circling above the precinct with prey in her talons. I did not get there early enough to see whether the male had brought this for her. The female took the prey to the feeding post on the north side of the spire and fed for a while before taking it to the nestbox to feed the young. The following clip shows her leaving the box at the end of the feed.
The male then went into the box immediately to brood the young but the female allowed him to do this for only a few minutes before she returned to take over again.
With approximately ten days of incubation remaining, it is interesting to see a change in the behaviour of the male peregrine.
During the first three two weeks of incubation, he stopped bringing food to the box. However, in recent days he has increased the frequency of his visits to the box and he has started to bring in offerings of food. In the image shown below, the male simply visits the box and then departs. He might have stashed food for the female before offering to take over incubation. This was his habit last year.
The male pays a visit to the nestbox.
Yesterday, he took what appeared to be a pigeon to the box and the female flew away with this to feed as the male took over incubation. A couple of hours later, after the female had returned to the eggs, the male made two attempts to deliver a small prey item – possibly a house sparrow – but his offer was declined.
Peregrines are equipped with sharp talons and they can, occasionally, cause damage to an egg as they step into or out of the nest scrape. To reduce the chance of this happening, the birds move very carefully , particularly when settling down on the eggs. In addition, they instinctively curl their toes to put the talons out of harm’s way.