Peregrines late hatching in the West Country

Like many other birds across the UK this year, Peregrines have been breeding later in some parts of the country. While pairs in the London area appear to be on time compared to previous years, those around Bristol are running a week or two later than they were in 2012. By now I would have normally ringed most of the Peregrine chicks available, but this year I am hoping to ring my first today! There are various reasons why this may be happening - it may relate to the condition of the adult birds after a cold winter; the availability of food (ie small birds); the cooler spring temperatures; and natural variation. Despite the late start, the chicks that hatched around three weeks ago appear to be doing well and are growing fast. More photos to follow of this year's young Peregrines. 

Eggs are cooking!

Just in the past week most Peregrines across the UK have been laying eggs (if they hadn't already!), and interestingly they have been incubating, or at least covering the eggs, from the outset. Usually Peregrines wait until the penultimate or final egg. However, with the recent cold weather Peregrines have been keeping their eggs warm and ensuring they don't freeze.

In Bath, the female Peregrine has laid four eggs over the past week (one every two days), and it will be about four weeks before they hatch. Both parents will help with incubating the clutch. The egg timer is running.....

 Peregrine eggs are smaller than that of a chicken, and covered in a brick-red mottled coating. Photo: Dave Pearce

Spring movements - little grebe eaten

Little Grebe. Photo: Hamish Smith

As waterbirds begin travel back to their breeding grounds, Peregrines are ready to snatch any on the move. Little Grebes are migrating across the UK at night, and many will be moving back to other parts of Europe. 

This head of a Little Grebe was found in Bath yesterday by Hamish Smith. It was probably a migrant, taken at night as it was flying over the city - city lights mean nocturnal migrants can be spotted by the falcons. Peregrines generally snip the heads off, although sometimes they will open the brain case and eat the brain which is full of nutritious fatty acids. 

What are the Bath Peregrines up to?

View from the Peregrine nest in Bath. Photo: Hamish Smith

Peregrines have been breeding in Bath since 2007 after the Hawk and Owl Trust (HOT) put up a nest box a few years earlier. The current breeding female is paired with her son who hatched in that first year.

Hamish Smith, who keeps an eye on the Bath Peregrines gave us the latest update as they prepare to lay eggs later this month.


"There hasn't been a huge amount of interaction between the pair in the past weeks, but more recently there have been some interesting behavioural changes.  

Both birds have been going through the motions of individually perch hunting from the church, but there has been little hunting activity in the vicinity.  It has become routine for the pair to head off in their favoured directions, and to return some time later with a kill.  In the time that I have been watching, there has been no evidence of prey sharing.

Fledged chick from 2011. Photo: Hamish Smith

In the past ten days, it has been clear that greater attention to detail is being paid to stamping ownership on the nestbox, the church and the surrounding airspace.  Within minutes of the HOT renewing the gravel in the nestbox a few weeks ago, the female entered the box and appeared to be shaping a scrape to her liking.

While the birds have in effect been ignoring one another in past weeks, in the week of Mon 11 March there were increased levels of activity:

• On a number of occasions with no birds initially on the church, the female flew in, landed on the roof of the nestbox and started calling.  She then has flown off.

• Wed 13th: Female spotted on the south side of the church on a gargoyle with a kill; male flew in, landed on the structure above her, and immediately started calling and looking down to her; she gave a cursory glance in his direction and carried on eating; female settled down on the gargoyle with a full crop, and the male headed off in the direction of Widcombe.

• Thu 14th: 08:00 to 09:00, female on north side of church, very alert and watching the wildlife go by; male sitting on the edge of the nest-box. 10:00-ish, female gone and male sitting inside the box. At 11:30 the top of a Peregrine head was visible in the box, assumed it to be the male.

Juveniles tassling in Bath in 2011. Photo: Hamish Smith

• Today, Sun 17^th: Male flew in to the church calling as he came in.  He flew off in the direction of Lansdown then circled over the Rec and returned to the church.  After preening and lightening the load he spent some time staring skyward and calling at a wolf-pack of gulls that were circling the tower.  He then lifted, scattered the pigeons on the church in so doing and headed off after one of the gulls.  They dropped below roof-top level and climbed on several occasions.  He either came very close or actually hit the gull then headed off towards Widcombe."

Teal wing feather, 5th March. Photo: Hamish Smith

Various prey items have been brought in over recent weeks - between us we have found  a fresh Snipe head, various pigeon legs, a pair of pigeon wings, Teal feathers, Brambling feathers and Skylark feathers. 

Sex on the Peregrines' minds!

It is that time of the year again - Peregrines are thinking about sex.

Bristol Peregrines: Sam Hobson

Peregrines in urban areas have already been spotted mating, although eggs won't be laid until the middle or end of March. In Bristol, Sam has spotted the city centre pair mating over the past few weeks. It is a great way for the pair to strengthen their bond, and for the male to make sure that when the eggs are laid, he is the daddy! 

While Peregrines usually nest in pairs, they will sometimes nip off to mate with other Peregrines - this is known as extra pair copulations, and is common in the bird world from Great tits to Swallows. So, a female's clutch of eggs may not always be fathered by her mate.  For her, it is a great way of making sure her young have the best genes possible, while also having a devoted partner to help her rear them!

Bristol Peregrines in the act: Sam Hobson

On sunny days, Peregrines will also be displaying overhead - lots of soaring, circling, and spectacular dives may be in the offering. While at the nest, the female may be testing things out by shuffling around where the eggs will be laid. You may also hear the pair calling to each other - recently described as 'ee-chupping' by the Derby Peregrines Project, the pair may cheap away, giving the odd light grunt in between.

In terms of prey, the Bristol Peregrines have been feasting on Feral Pigeons, Woodpigeons, and the odd Teal throughout February. As we get into March, prey species migrating back to their breeding grounds, such as Redwings, Woodcock, and Water Rail, will begin to appear in the diet again. The male may even impress the female by bringing her some food, and transferring it to her in the air. It is his way of telling her that he is a good provider, and that he will make sure her and the chicks will be taken care of when they need to be fed. 

Waders on the menu for Bristol peregrines

Since the temperature has dropped in the last week or so, the Peregrines that are often seen around Bristol city centre appear to have become increasingly active. They must have been hunting and caching around the clock, as recently I have found the remains of a much wider variety of prey species under their perches than I have for months - many of which, would have only been flying over the city under the cover of darkness.

Last Sunday, it was a bumper haul, with Dunlin, Snipe, Little Grebe, Teal, and plenty of more common urban birds like Starling, Redwing, Goldfinch, and Feral Pigeon. Mid-week, I found some Lapwing tail feathers, and this weekend, a male Teal, alongside some nice Golden Plover and Woodcock feathers.

It might be that the cold snap has prompted the increased hunting frequency, and they are busy caching extra food, or it could be that the drop in temperature has caused some movement of waders and ducks.

The only other explanation could be that there is a new bird in town, who is more expert at hunting nocturnally. As Ed mentioned in the previous post, it is important to keep an eye on who’s who at this time of year. 

Just recently, I have noticed that a juvenile Peregrine that has been hanging around with the two adults in the centre of Bristol has no colour ring on its left leg. If this was the city centre pair's offspring from this year, we would expect it to be sporting a colour ring on its left leg with the letters FP, clearly visible here. Therefore, this young bird is either FP, and has lost his ring, perhaps after a high-speed strike, or it is a roaming juvenile that has temporarily taken up residence in Bristol. It’s hard to be sure without getting a look at the BTO metal ring on its right leg, but watching its behaviour - particularly its choice of perches that I’ve never seen FP use before - I’m inclined to agree with Ed that it is not a local bird. Frustrating situations like this illustrate why colour-ringing is so important to urban Peregrine studies

Peregrines wintering in Bristol and Bath

These days you are more likely to see a Peregrine in an English city thank you are a Kestrel or Sparrowhawk. 

As we are head in to winter, urban-dwelling Peregrines are spending plenty of time hunting and roosting over towns and cities. Here in Bristol, various Peregrines are using different buildings as their base throughout the city. One pair which raised one chick in the centre of Bristol this year are still around - just the other day they were spotted by Peregrine watcher Sam Hobson.

During the winter, Peregrines will stay close to their breeding territories, but many younger birds (known as satellite birds) will be roam around the UK, and may turn up in areas where during the summer they would normally get chased off very quickly by territorial birds. 

Over the next few months we will be reflecting on the 2012 breeding season and some of the interesting results we have received from some of the young birds we have colour-ringed over the past few years. I have been studying Peregrines in the Bristol and Bath region since 1998, and with the help of others who watch, study and photograph Peregrines, we are developing a bigger and more detailed picture of how these birds live in our towns and cities. 

I am linking to our previous blog below which followed some of the comings and goings of the Peregrines in recent years throughout the west region in England. We will now put postings on this current blog but didn't want to lose the stories and information shared on the blog below. 

http://swperegrinestudygroup.blogspot.co.uk/

Ed Drewitt November 2012
eddrewitt.com