Author: davidwoodsbsg

An Eventful Quiet Week

The month of incubation is generally a quiet time, but the first of the ‘quiet’ weeks has been anything but…  As I mentioned in the previous post, it’s always a roller coaster and I did wonder if (yet) another cold snap would give cause for concern.  Well, the start of April did indeed bring such a cold snap, and with it a quite substantial fall of snow, waking up to some 10 cm on the western side of Sheffield on the morning of Monday 2nd (Easter Monday).    A quick check of the webcam showed that the eggs were safe, thanks to the devotion and commitment of the parents, particularly the male, which sat tight through the worst of the snow.

April 2 2018 snow male

Once the snow had stopped, he changed position and shook himself off before settling back down.

April 2 snow male 2

Fortunately, the temperature wasn’t too low and the snow began to melt fairly quickly, and by the time the female took over incubation duties later in the morning it was already starting to go.

April 2 snow female

When analysing the two eggs that failed to hatch in 2015, Dr Nicola Hemmings (of the University’s Department of Animal and Plant Sciences) commented that early-stage embryos tend to be fairly resilient to changes in environmental conditions, such as cold temperatures or delayed incubation, but the risk to the developing chicks is real.  Hopefully the committed efforts of the adults will mean that risk has been averted.

The other excitement of the week came when we learned that the team at Wakefield Cathdral have been able to read the ring of the male of their pair, and the ring number confirms that he was ringed at St George’s on 16th May 2014, one of the four chicks that fledged that year.  We’ve suspected that the ringed Wakefield male could be from Sheffield, and it is absolutely fantastic to know that this is the case.  How wonderful to know that the St George’s birds are contributing to the growing urban Yorkshire population, especially when birds in rural settings continue to struggle as a result of illegal persecution.

Great too to know that the ringing carried out by Sorby Breck Ringing Group is helping to build a picture of what happens to the Sheffield chicks once they’ve fledged.  This is the first definite proof of successful breeding of any of the Sheffield offspring and it’s really interesting that it should have set up in another urban environment.  And how fitting that we were able to advise the team in Wakefield on their plans to support Peregrines and provide them with their first nestbox, an exact copy of the St George’s model.  They’ve since moved on to a different nestbox, but the pair there have fledged 10 chicks and are on course for another successful season too.  A real snowball effect.

We’ve still not managed to read the entire ring number of the St George’s male, so if anyone fancies a challenge over the weeks ahead, it would be terrific to be able to find out where and when he was ringed.  What odds he’s also from an urban nest?

June 2014 4 chicks

It seems only fitting to close with an image of the 2014 chicks shortly before they fledged, with the Wakefield male somewhere among them.  Perhaps this is him below, taking one of his first flights and grappling with a sibling back in June 2014.  What a week!

June 2014 grappling two

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2018 season up and running

With little time to devote to the blog this year, my first post is to celebrate the laying of the fourth egg today, which should complete the clutch.  Below is a screengrab of the male settling back down to incubate this evening, with the four eggs visible and a good idea of how a clutch of four is about the limit of his brooding capacity.

Male and 4 eggs 29 March 2

The news that the pair had started to lay eggs has generated a good deal of interest, and the University’s digital media team, Andy Kershaw of BBC Radio Sheffield and the Sheffield Star have all done interviews over the last couple of days.  It’s always great to know that there’s so much interest in the birds and great too to be able to spread the word and share some knowledge about them.

Spending an hour with Andy Kershaw at St George’s in the early morning sun was especially fun as it coincided with a good deal of activity.  With the female on the corner of the Arts Tower and the male on incubation duty, a Crow mobbed the female, shortly followed by another bird that didn’t look like a Crow, even with the naked eye.  A quick check with the bins confirmed it was a third Peregrine, which made repeated passes within feet of the female.  The pictures below were taken from St George’s, so at some distance…

PG fem and imm March 29 2018

PG fem and imm March 29 2018 3

The female eventually flew off in pursuit, although made no effort to attack the interloper, instead engaging in some half-hearted chasing.

PG fem and imm March 29 2018 2

The size difference and heavy streaking below on the bird to the left in the image above indicate that this third bird is a young male, fledged last year.  The images below also shows that it is quite brown above still, confirming it’s around a year old.

PG fem and imm March 29 2018 4

PG fem and imm Arts Tower March 29 2018

My immediate thought was that it could be one of last year’s chicks, which were fitted with orange plastic rings to aid identification and track their movements.  However, a few pictures snapped when it dropped its talons as it passed the female didn’t show any obvious ring of that kind, which I’d expect to see, even at that distance.

PG fem and imm March 29 2018 5

It could be that the plastic ring has dropped (or been pecked) off, or it could possibly be an immature male that fledged elsewhere and has moved away from its nest site to find Sheffield to its liking.  Seems a bit of a long shot, especially given the female’s relative acceptance of the immature, although we may never know for sure.

Back to the eggs, the sequence of laying dates is now probably complete, and was March 22nd, March 24th, March 26th and March 29th.  This pattern of laying the four eggs across the space of a week fits perfectly with previous years, but they have come a couple of days later than in recent years, which have seen the first egg laid on 19th or 20th March for the last four years.  Given the weather we’ve been having recently, and especially the overnight temperatures, perhaps this delay isn’t surprising.  On the basis of previous years, we can expect the first egg to hatch in late April, probably 29th, with fledging likely to occur around June 6th.  In the meantime, there will no doubt be a roller coaster to enjoy/ endure.  Will we have another cold snap that threatens the development of the embryos?  Will one of the adults puncture an egg with its talons (as appears to be imminent in the screengrab below from this evening)?

Male and 4 eggs 29 March 2018

And finally, if you do go down to St George’s to see the Peregrines (and you should!), keep your eyes open for other species too.  Woodpigeons, Magpies, Blue Tits, Blackbirds, Starlings and Mistle Thrushes are all busy with their breeding seasons around the church.  This Pied Wagtail was also there, busy catching insects around the church’s ledges this morning, under the gaze of the Peregrine above.

Pied Wag and PG March 29 2018

Blog updates won’t be as regular as in previous years given various other commitments, but I’ll try to keep on top of major developments.

Summer sign-off

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.

Juv PTF Aug 6 2017

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.

PGs and pigeons Aug 6 2017

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.

PG male and pigeon Aug 6 2017

PG male and pigeon Aug 6 2017 2

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 chairman@sbsg.org

First Flight!

Friday night’s public talk, attended by some 140-150 people, was great, with very informative contributions from Dean Rea (Sorby Breck Ringing Group) and Deborah Dawson and Natalie dos Remedios (Dept of Animal and Plant Sciences her at Sheffield University).  Dean explained the thinking behind the colour ringing of the young birds this year (details to follow) and Natalie’s finale was to reveal that all three of this year’s young birds are… male! So that makes three years of males only.

The weather ahead of the talk was damp and far from ideal for watching the birds, let alone for them to make their first flights, although a good crowd enjoyed fine views of the birds through the telescope available.  On Thursday evening (1st June) a trip to St George’s proved exciting, with plenty of activity.  Most notable was the female’s visit to the church tower with some prey that she brought to the corner of the ledge a couple of metres from the nest platform (in the photo below), but did not take into the box.  She seemed to be clearly trying to encourage the young birds to move beyond the nest, but despite their loud protests and obvious desire to reach the food, they did not budge!

June 1 no feed

Yesterday (Saturday) evening was fine and sunny so a visit to check on progress seemed in order.  The three juvs were very active on and around the box, with two of them ably going up on to its roof and one flapping/ hopping out onto the webcam housing.

June 3 flapping

There’s obviously not much room on top of the box, and the more adventurous juv clambered over its brother en route to the webcam housing: those talons must have been uncomfortable!

June 3 clambering

Both adult birds were close to hand, with all five on and around the nest site on occasion.  The female landed on the webcam at one point, and when she dropped away there was a sense of the juvs watching and learning.

June 3 all 5

The amount of downforce generated by the vigorous flapping undertaken by the young birds as they exercise ahead of their first flight was apparent when one gave it a good go on the edge of the box, raising a cloud of down (which they are rapidly losing completely) and small feathers, some presumably from inside the box.

June 3 feathers flying

By the end of the evening, the moon rose behind the tower and provided a photo opp that was too good to resist as the birds settled down for the night.

June 3 moon

This afternoon, one of the juvs was on the corner of the ledge having made its first excursion from the nest.

June 4 one on ledge

And this evening, news from Andy J that one of the juvs hopped/ flapped up onto the castellations behind the box, only to slip down and take flight, circling the tower and landing back on the roof in reasonably controlled fashion.  So we have lift off!!

 

 

Friday 2nd June

This Friday is a day of a definite and a possible: the definite is the Peregrine talk at St George’s from 7-8 (p.m.!), with contributions from Dr Deborah Dawson and Dr Natalie dos Remedios (Animal and Plant Sciences at the University of Sheffield), Dr Dean Rea (Sorby Breck Ringing Group) and Professor David Wood (Sheffield Bird Study Group).  We will cover the different key aspects behind the Peregrine project, and from 6:00 p.m. there will be telescopes on hand for the chance to watch the Peregrines and ask questions.

May 29 1

The possible is the young birds taking their first venture out of the nest, which is expected over next weekend, but could come on Friday.  As is apparent in the picture above (and can now be seen when watching from below), they are giving their wings some good exercise, building up their flight muscles ahead of the big day.  With less than a week to go until then, the young birds are taking an increasing interest in the world around them, and life beyond the nest platform.

It never fails to amaze how quickly they transform from essentially white and fluffy ‘squatters’ to scruffy versions of their parents in terms of overall appearance.  The screengrab on the left was from May 25th, and just four days later their feathers have continued to grow through the down, which is also being plucked out as they preen.

May 29 5

However, they still look very un-adult like when they huddle together to rest, lying flat with their heads down.  If you didn’t know there were three Peregrine chicks in the nest, working out what that pile in the corner is could be quite a puzzle!

May 29 6

By Friday most of the remaining white down will have been lost or pulled out and the young birds may well be flapping their wings on the edge of the nest, making us wonder if they’re about to go…

Hope you can join us on Friday, and spread the word!

 

Four Weeks Old

Today marks four weeks since the first chick hatched, and the three young birds continue to grow and develop well.  As is always the case at this stage, they are changing their appearance rapidly as their feathers grow through.

May 25 4 weeks

They will carry on changing over the next 10 days before leaving the nest, which may even coincide with next Friday’s talk in St George’s church.  It’s hard to believe it’s that close given how they look at present, but the down will soon be lost, they will stand (rather than rest on their ‘ankles’) and start to exercise their wings with increasing regularity and vigour.

May 24 night feed

The screengrab above shows one of the feeding sessions and the poor quality is explained by the time it was taken – 10:15 p.m.!  This is unusually late in the day for the Sheffield pair, which was not observed to engage in night feeding in the extensive footage that Esther Kettel reviewed as part of her PhD, though some pairs did (as she reported in the Journal of Raptor Research).  A couple of minutes later, the webcam switched to its night mode, almost exactly an hour after sunset, so perhaps we can count this as a night feed for the St George’s pair.  Unfortunately, I couldn’t make out the prey, as Peregrines are known to take bats!  For an urban pair, the presence of city lights may provide additional opportunities to hunt at night, thought there has been little evidence of this here in Sheffield.

May 24 night feed 2

Perhaps worth keeping an eye out for any further examples of this uncommon behaviour if you find yourself suffering from insomnia!  And a couple of minutes later again, the female hopped out onto the perch and the chicks settled back down for the night.

May 24 night

 

 

Ringing the changes and a diary date

With the chicks now in the ideal window for ringing, this morning’s good forecast provided the perfect opportunity to ring the chicks.  It’s always a slightly nervy time, but thanks to the expertise of our friends from Sorby Breck Ringing Group, very ably led by Steve (who has the necessary license to ring Peregrines), everything passed off very safely and smoothly.  Also important is the collaboration of colleagues in the University’s Estates Department, with special mention to Phil R and Steve H for their part in making it possible for this to take place.

May 18 ringing 2

In addition to Steve, Dean and Simon (the intrepid climber who goes over the wall to gather the chicks from the nest, securely roped of course), in picture above is Natalie from the University’s Department of Animal and Plant Sciences, who gathered material for analysis in their laboratories.  This is part of the developing involvement of the team there, who are contributing to our understandings of the birds both locally and within the national context.  As well as collecting pellets and faecal samples, we also took swabs to enable DNA analysis (as below), which will hopefully serve various purposes.

May 18 ringing swab

As the chicks were being processed for ringing, Steve took a series of detailed measurements, recorded by Natalie, that will help to build the picture for Peregrine chicks, for which there are few data nationally.

May 18 ringing 3

Another innovation this year was to fit unique colour rings to the chicks, which will make it possible to track their individual movements after they leave the nest, and potentially leave Sheffield.  Details of the identifying features of the rings to follow!

May 18 ringing

Being able to do this is a direct result of the funding raised through the kind donations to the Peregrine project; do please keep the donations coming so that we can do as much as possible with the material gathered today and taken to the labs for analysis.

May 18 ringing 5

As ever, the only downside to this is the brief disturbance caused to the adult birds.  Both were in the vicinity throughout, and while the male circled at quite a distance the female circled the tower, calling frequently.

May 18 4

May 18 3

The up side was seeing how some local residents came across to check what was happening, concerned at the disturbance to the birds.  It really is terrific to know that people in the area have taken the birds to heart and look out for them.  By the time we got back down to the bottom of the tower, the female was back on the nest and things quickly settled down to normal again.

May 18 5

With the webcams switched back on the chicks are now sporting their BTO silver rings and the colour rings, which will be more visible when they begin to stand, rather than shuffle as the do at present.  That will be one of the next developmental steps, as will the appearance of their feathers, which you can occasionally already see starting to come through when they move around or stretch in the nest.

And the diary date?  On Friday 2nd June we’ll be having a public talk on the Peregrines in St George’s from 7:00-8:00, when we aim to be able to share some of the findings from the data and materials collected today.  That will also be very close to the date that the chicks take their first flight, so from 6:00 there will be the chance to see the birds from the church grounds through telescopes and binoculars, and to ask questions.  Hope to see you there!

May 18 8