Friday, 29 February 2008

Ravens, Crows and Peregrines

Two black ravens are visible on the gargoyle ledge, whilst a peregrine hovers momentarily above, trying to dislodge them. Click to enlarge image. On Friday morning we saw clear evidence that a pair of ravens are still present around the tower of Derby Cathedral. The ravens were feeding on a stored corpse of a laA peregrine swoops down from above in an attempt to dislodge a pair of ravens. Click image to enlarge.pwing (we knew this because we'd seen snipe, golden plover and lapwing corpses on the upper ledge the previous day). Not surprisingly, this annoyed our peregrine, though not to the extent it had earlier in the week. From time to time the peregrines made repeated swoops in an attempt to drive the ravens away. They took little notice, even when one peregrine hovered right above them for some moments as can been seen in the left-hand picture.

Both ravens later moved off to the roof of a nearby building and started pestering a crow. You can clearly see how much larger they are then their smaller cousin as the picture below shows the crow perching on top of a satelite dish.
Notice how much large the ravens are than the crow which is perched on top of the satellite dish.
Ravens were seen on the roof of the building with a satellite dish, adjacent to Derby Cathedral.

New visitors to this blog you may wish to read an overview of the peregrine project, or add their names to our mailing list.)

Third camera takes a step closer.

I took a few hours off work yesterday to thread video cables up the four hundred and fifty year old spiral stone staircase of Derby Cathedral's tower. This done, it was a delight to be able to test out what everyone has been calling "Pudding Cam" - a dome camera generously donated to us by Acam Technology Ltd in Derby.
View down the spiral staircase inside Derby Cathedral during video cable installation
It was only a temporary installation, so there's no live images to show yet, but here's the first test picture. It is designed to sit on top of one of the lead gutters and should give us a great view across the "gargoyle ledge" at the very top of the tower. Our thanks go to Steve and the folks at Acam Technology who found us a camera that would fit through the tiny hole in the guttering. We only had to pay for the power supply and cabling, so the cost to the Peregrine Project was effectively halved. Follow this link to see more on our tests with Pudding Cam.

We also renewed our contract with Streamdays today, so broadband users should now be seeing pictures refreshing at least every six seconds. We hope that Streamdays might be able to speed this up a little more for us, though it could involve a reduction in image size - we'll see. Visitors do need to have Flash installed on their computers, and we hope to hear from dial-up users that they're still getting pictures OK. (Please remember to close your browser after watching, rather than leaving it running in the background.)

New visitors to this blog you may wish to read an overview of the peregrine project, or add their names to our mailing list.)

Wednesday, 27 February 2008

News Flash 2 - and now an Earthquake!

Just around 1am GMT this morning my house shook as if some giant hand was gently pulling off its roof. Clearly a minor earth tremor, I checked first on the family, then went outside into the street to - well, total silence. Was it imagination? There was not a sound to be heard. No alarms, no falling masonry. But eventually a call from a neighbour's window showed I wasn't alone in feeling the vibrations. Indeed, within half an hour BBC national news was announcing first reports of a widespread tremor felt across a wide area in the Midlands and northern England.
But actually all was not quiet outside. The night itself was still and calm, but all around there had been a gentle but constant sound of wings beating. Birds were flapping in the branches, having been disturbed in their roosts, and were settling back down again. Quite a number of these sounds seemed to be overhead, yet were invisible to me.

Perhaps our peregrines took advantage of this disturbance, who knows? Recent research has shown that peregrines are now adapting to hunt at night, using city lights to help them find their prey highlighted against the dark sky. Perhaps an earth tremor seems an unlikely cause of extra food becoming available to a peregrine. But already 2008 is proving to be an interesting year, and perhaps there are many more surprises still to come.

(New visitors to this blog you may wish to read an overview of the peregrine project, or add their names to our mailing list.)

Monday, 25 February 2008

News Flash - Ravens on the Tower!

News is coming in from Tony, the Head Verger at Derby Cathedral, to say that a pair of Ravens are fighting with our peregrines in the skies over Derby. (dateline Monday lunchtime -12.30pm GMT) It seems the Ravens are trying to bring nesting material to the south side of the tower, much to the consternation of the resident Peregrines who are trying to see them off. For those of you watching the blog in the Derby city centre area, you might wish to pop over and see if you can catch some of the action. We'll bring you a fuller update when we know more. Follow this link for more on Ravens. Check the comments to this post for the latest news from watchers in town.

Monday, 18 February 2008

Courtship Activity

Close-up of female peregrine standing in the nest scrape. Click image to enlarge. Welcome. If you're a first time visitor to this blog you may wish to read an overview of the peregrine project, or add your name to our mailing list (see below)

The courtship phase has now begun, although it does seem to involve a lot of standing around. Our peregrine falcons were quite unmoved by our recent abseil to prepare their nest ledge for 2008. Within a day they were back on the platform, bowing intently at one another. We should see more and more of this activity in the weeks ahead.
Courtship in most birds is triggered by increasing day-length, and peregrines are no exception. It usually begins with the male standing in the nest scrape that he (mostly) has made. The female arrives with loud and repeateThe smaller male does most of the work in maintaining the nest scrape. Click image to enlarge.d "ee-chupp" calls. With his head down, the male remains static for four or five minutes, stared at by the larger female on the far side of the nest ledge. Almost looking as if his nerve suddenly gives out, he flies off, leaving the female alone. A minute or two may pass before she plods over and stands in the empty nest scrape. Turning a few times, she may also give a few scrapes at the gravel herself, before eventually moving to the edge of the ledge where she may remain for some time.

The much larger female will move over to inspect the scrape after the male has finished his head-bowing display and has flown off. Click inage to enlarge. You may be lucky enough to see head-bowing or nest-scraping activity in the freeze-frame of our webcams. You may also witness the male pass food to the female - another important part of their courtship.

The webcams have now been readjusted, with camera 1 set to the centre of the scrape. We hope to upgrade the webcam service for 2008 so as to give a much faster image refresh, plus a photo archive facility. We'll keep you informed of all these developments in the months ahead.

Mailing List
Would you like to receive a direct mail-shot of any key events? If so, please send an email to with your name, nearest town and your country, and we'll add you to a new mailing-list. Please tell us if you're a teacher who uses (or would like to use) the webcams in class , as we may be able to send you more specific information to meet your needs. (We may share the list between the project partners to inform you of related events, and you can request removal at any time.)

Note: We've now moved the overview of our Peregrine Project to be the first entry for January 2008.

Monday, 11 February 2008

Dem Bones, Dem Bones, Dem Dry Bones.

What a lot of excitement around Derby Cathedral recently!

First we hear that during landcaping work on the once grassy area outside the Cathedral workmen dug up a human skull last Friday. Work stopped for a time whilst police carried the bones away for investigation. But it resumed again today, though local newspapers suggest it could be halted again if the ancient remains turn out to be Anglo-Saxon in age. We might then end up with a full-scale archaeological investigation. As you can see, the once green Green is now a more muddy brown, but should be ready finished sometime in the summer.

And then we ourselves had our hands full, Nick Evans adjusts camera 2, having just helped scrape up many bird bones and feathers from the peregrine nest ledgequite literally, with the bones and feathery remains of quite a few past peregrine meals, which we collected from the Cathedral roof and scraped from the peregrine's nest ledge during a routine abseil for camera maintenance earlier today. Shown here is Nick Evans, dangling from a rope whilst adjusting the camera, having first donned mask and gloves to help clear up the grizzly remains of lapwing legs, woodcock wings and pigeon parts. These are now being frozen to kill off any blowfly eggs, before being passed for identification to Bristol Museum's bird expert, Ed Drewitt who joins us later in the week to inspect our set-up.

We were surprised by how much young grass was sprouting from the nest ledge until we realised it wasn't grass - it was wheat. And there were peanuts too, though these weren't germinating. Surprised at first, it soon became clear that these must have come from the crops of seed-eating birds which our peregrines had brought back to the tray. Meanwhile up on top of the tower there were a couple of fresh Golden Plover corpses, and a bit of old Lapwing, proving that our birds are still active. We had two film crews today, both watching our progress as we lowered ourselves over the side of the tower, and some of this footage should appear in the new peregrine DVD to appear later in the year.

Thanks to everyone's efforts, our cameras are now back, pointing the right way and with clean lenses, though we're still struggling with night-time focus on camera 2, which seems to prefer the street below than the ledge itself. Because it's a fixed-focus camera we have a choice between a clear daytime picture in natural light, or a clear one at night under infra-red. It's hard to get both, it seems. This unusual view of camera 1 shows the anti-perching spikes we had to place on our cameras to keep the weighty birds from knocking them out of alignment. These were donated to us by our Council's Pest Control Team. Below the camera is a small infra-red illuminator. We hope our adjustments will prevent the cameras switching from day to night mode every few minutes whilst the tower floodlights are in use.

Exciting News

The BBC and Delta Echo Media both film our peregrines on Monday morning with Derbyshire Wildlife Trust's Nick Brown.As we begin to approach the 2008 breeding season, we have some great news items to announce.

Firstly, work started today on the filming of a DVD on "The Peregrines of Derby Cathedral". We were approached by a commercial company, Delta Echo Media, to help them produce a documentary on Derby Cathedral's peregrine falcons. This fitted in perfectly with our aim to promote awareness of these incredible urban predators, as well as raising funds for the partners to put towards our conservation efforts. The DVD should be available for purchase by April and, for the moment, forgive us if we hold back on the news of the major BBC TV presenter we hope is agreeable to contributing to our film.

Also today we had BBC TV's East Midlands Today coming to Derby to film. (So we ended up filming the filmers!) BBC TV had picked up on the national news story that peregrine falcons around the world are now beginning to use the lights of our big cities to help them see their prey when they hunt at night. Follow this link to read more on this story. Here's a clip we captured in summer 2007 of what we thought at the time was a Snipe, but opinion is now mixed, and it could conceivably be a Green Sandpiper. Notice the light underbelly in the infra-red illumination, which would make it stand out at night against a dark sky, making it easy prey for a fast-flying falcon. It was brought to the platform at 1am, but of course it could have been brought from a cache elsewhere on the tower. What we really need is a thermal-imaging camera!

Ed Drewitt from Bristol Museum & Art Gallery is one of the pair who published the article on peregrines hunting at night in "British Birds". We're looking forward to welcoming Ed to Derby later in the week when he comes to have a closer look at our webcam set-up.

"Pudding-cam" has now been ordered for the top of the tower from Acam Technology, and we hope to be able to quickly run a cable up the 400 year-old spiral stone staircase to do a short test before making a proper install in the next month or so. We're all looking forward to seeing how well we can view the peregrines on top of the Cathedral's gargoyles, and perhaps capture more intimate footage from a really close vantage point.

And finally, the weather stayed fine to allow us to abseil down the side of the Cathedral today to re-adjust our cameras and check and clean the platform. We forgot to take the camera feed offline whilst we did this, so our apologies for any weird pictures or close-ups of dangling legs you may have seen around noon (GMT). We were pleased to have had Nick Evans helping us again, as he's the man who built the peregrine ledge for us, and he report that it's still in perfect condition. (Our thanks to Mary, a Museum volunteer, who also helped us out on the day)

Tony, Nick & Nick
Derby Cathedral Peregrine Project