Friday, 8 November 2013

Fly by night.....and teal and woodcock updates

A quick trip to the top of the tower today (8th November) hoping to find some prey remains looked like being a bit of a wash out (it was raining too by the time I got up there).
There was very little on the roof (someone had been cleaning up I suspect) and also the tops of the 'grotesques' on which the peregrines often sit and leave prey remains were also almost devoid of anything except for the head of a teal - well out of my reach.
However tucked away in the lead spout at the far end of the east side (as seen from the 'pudding' camera that looks across the ledge), there was the corpse of a recently taken wader.
I managed to pull it out and quickly identified it from its size, grey colouring and wing pattern as a knot, a small wading bird.
Left wing of knot showing its wing bar
Knots breed in the arctic but travel south in autumn. British estuaries and bays such as the Wash, Morecambe Bay and the Severn Estuary host thousands of knot (and other arctic waders) during the autumn and winter.
The knot's leg  (tarsus) and foot
This is a common and widespread species occurring in North America as well as Europe and Asia.
In summer the breeding birds turn red underneath which explains their american name - red knot. It's scientific name is Calidris canutus, named after King Canute who famously tried to defy the incoming tide. These waders run along the tide edge and hence the connection.
The link below shows a knot in winter plumage in flight so the wing pattern can be compared:

http://ibc.lynxeds.com/photo/red-knot-calidris-canutus/flight

(More photos and videos of knots can be found at http://ibc.lynxeds.com/species/red-knot-calidris-canutus and on a BBC site at http://www.bbc.co.uk/nature/life/Red_Knot )

The corpse did not smell but wasn't completely fresh so I would guess it was caught the night before last (5th-6th) but obviously I can't be sure. I've not checked to see yet it that ties in with any observations reported to the blog.
Knot are very rarely seen on the ground in Derbyshire and since they migrate at night, I would be confident that this bird flew over Derby after dark perhaps on its way from The Wash to the east to somewhere on the west coast - an easy overnight journey for such a bird. Sadly for the knot, it didn't make it.....
We have recorded knot as prey here at Derby before on eight occasions (this being the ninth) and I recall the species has also been found at Coventry in the West Midlands.
UPDATE 10th November: screenshots taken by Phoebe last night showed a female teal as prey. This small duck is regularly on the menu (except in summer). The photo below shows the green speculum feathers and some of the white bars above and below them:
Pair of wings from a teal found a few years ago at the cathedral
Other prey remains found recently included wood pigeon, woodcock, starling, little grebe, feral pigeon and the knot of course.
Update 12th Nov: a woodcock that had flown into a Derby window and broken its neck was made available to me yesterday. Here are some photos of this beautifully plumaged bird. It is considerably larger than the knot and much heavier too...so more of a meal for a peregrine.
Woodcock - what wonderful plumage!
Unlike knot and other waders, woodcock are entirely nocturnal birds, feeding at night in wet meadows and marshes where they probe for worms with their large straight beaks. Before dawn they fly into woods and settle on the woodland floor, superbly camouflaged among the fallen leaves and the vegetation. Probably something like 100,000 woodcock fly to the UK from Russia, Eastern Europe and Scandinavia to spend the winder with us. Some have been satellite tagged so we know exactly where those birds were breeding.
Many get shot or have accidents while migrating or on arrival here (like this one). A relatively very few are taken by peregrines.
As you can see, woodcock are very dark birds, have no wing bar (unlike the knot) and therefore look quite different when seen on the web cams.
Nick B (DWT)
Ps. The adult male was on the nest ledge when I arrived and the female on Jurys Inn. No sign of a third bird.

29 comments:

Lorraine said...

Very interesting update Nick, and the links will be really handy. Also a nice website link for bird identification to use in the future, so I've added it to my "favourites"

I wonder if it was a knot ( or not!) that was brought onto the scrape ( some of it still there ) around the time of the spout stash - though I think I remember it had yellow legs, so was prob a woodcock as thought.

Anyway, from the point of view of Peregrines "taste" receptors, and considering the very different diet's of say a knot and an urban pigeon, then there must be a significant and distinct texture and taste between the two types of catch. That, I find very interesting to explore further, so off now to do some research!.......................

Sue Peregrino said...

Poor little knot, they are such fabulous birds when seen en masse as one of our British winter spectacles. Take a trip to Snettisham on the Norfolk coast of The Wash at a spring tide (in daylight!) and you will see a sight that you'll remember for the rest of your life. The birds scrunch up onto the mud further and further until the tide eventually pushes them off (for as with King Canute, they find they cannot command the sea) and then tens of thousands lift and they swirl in the sky like a massive cloud of smoke. Stand in the right place and they'll go right over you and you'll hear the thousands of wings beating. No way would any predator stand a chance of picking off one as prey in that situation! So, a sad end for one little knot but there are thousands more still there. Proof once again that the Derby urban peregrines are adept at hunting by night when the migrants are on the move. This must be a bonanza time for our favourite falcons!

Phoebe said...

The falcon has just landed on the tower top with fresh prey, it looks quite large too!

Lorraine said...

Can see it also Phoebe - likewise unsure of what the catch is.

Phoebe said...

Although it is dark and colours are not seen, the feather pattern is very speckled very like the knot pictured on this post. I will put pics on flickr later for possible ID.

Lorraine said...

Yikes, there goes the head which she dropped purposely over the edge. It had a long beak I noticed and it's wings have white stripes - perhaps a wader of some sort? Looks like she's contemplating relocating with it - yes she's off with it in tow and now up on top of the cam !

Phoebe said...

Wow she showed us some wings just then, she has flown off with the catch but I think she has put it up on tom of the pud cam. I got some nice pics of her wings open, it also showed the size of the prey.

Lorraine said...

Well she made short work of that one. Now back on watch up near the spout looking for more nightflyers - greedy Mrs.T !!

Phoebe said...

photos on flickr now. They always come back to front. I must look at how to get them in order.

Lorraine said...

Some clear images there Phoebe - hopefully someone will now be able to identify the catch in a later post. Well done good buddy !

Phoebe said...

I hope so Lorraine. I wonder if it could be a woodcock? They do have stripes on the wing but not sure if it looks the same.

Nice to know someone else is watching at the same time :D

Lorraine said...

The more I look at the woodcock depicted in the snow on one of Nicks updates, the more the head and beak of the catch made me also think it could have been a woodcock. The falcon is content to sit dozing on and off just now, but I'll keep tuning back in now and then, to see if she stays overnight.

Lorraine said...

Yet... after looking closely just now at an image of a knot ( see BP ) the head and beak of the catch were exactly the same, whereas the woodcock's beak is much much longer. So I'm going with the knot ( for now anyway! )

The falcon is presently fast asleep with head tucked under wing!
Night all...........

nICK b (dwt) said...

Hi Phoebe/Lorraine: from the flickr screen grabs I'm fairly sure this is a female teal - a small species of duck which the falcons take regularly during the winter. Look at _034 and _036 and you can see the bird's speculum - a coloured patch at the base of the wings. In teal it is green with white bars at top and bottom of the coloured patch. On _021 you can see the head and the beak which is small and dark but broader than any wader beak would be.
Woodcock have no white marks on the top of the body or wings and a knot would be a lot smaller than this bird. Hope that helps. Great screen grabs Phoebe!
Nick B (DWT)

Phoebe said...

Nick B, thanks for the ID. I did think of a duck of some sort when I saw the stripes but didn't look into it. I didn't expect they would take a duck! But as you say teal are smaller than the average mallard.

Anonymous said...

Just a note to say that the webcams will be offline on Tuesday morning from around 10am while we PAT test all the (very dusty) IT equipment inside the tower. Hope to be back online soon afterwards - barring disasters.
Nick Moyes

Helen said...

Both birds are visible on the cameras this morning, with the male on the tower and the female on the platform.

Don Newing said...

Just seen a picture on the RSPB Love Nature Facebook site of a Peregrine attacking a pelican!

Phoebe said...

Nick B, thank you for the information and photo of the woodcock. I knew very little about them until now. They are very beautifully feathered which I can see blends in with the Autumn colours. I didn't realise they were nocturnal and that they roost on the ground during the day. I will tread more carefully amongst the fallen leaves from now on when walking my dog.

There is an adult on the corbel to the right of the scrape.

Lorraine said...

The woodcock is quite literally wearing the Autumn colours - how beautiful- had no idea! Also that vivid jewel green flash on the teal's wings flanked by white stripes is just gorgeous.

Me thinks I will be investing in some " proper " binoculars in the January sales. The more I enter into the world of birds, the more my heart sings with joy !!

Lorraine said...

....Even the common starling is transformed by the light !

Green Class said...

we trid to ges the name of the bird in one of the pictchers. these wer some of awy gesess -
woodland, woodpeker, wood chopper, wood cutter,and woodzone. it was a woodcok.

Nick B (DWT) said...

That's an interesting set of guesses Green Class - well done in getting to the right answer in the end!
It is amazing that these woodcock have flown to Derbyshire such a long way...even from Russia. have you looked on a map to see where that is or try to work out how far they have flown to get here? It's a long long way for sure!
Nick

Lorraine said...

Brrrr - weather very chilly now and haven' seen any of the birds over the last few days. They're probably using a different location for the time being. Looks nice and sunny in Derby this morning though, so maybe they'll make an appearance sometime today.

Phoebe said...

It is very cold at the moment. No peres in sight.

@Lorraine - There was an adult on the spout last night around 11pm

Phoebe said...

For Lorraine - I hope you are watching the cams - there is a close-up of the falcon on the tower.

Lorraine said...

Hi Phoebe - I tuned in late tonight but pleased to see the falcon you saw earlier still on the tower and looking around for night flyers.

She looks quite rounded with her feathers trapping the heat inside like a nice warm duvet !

Phoebe said...

The tiercel is on the ledge of the scrape eyeing up some food remains. Not seen him for a while. He looks in good fettle.

Anonymous said...

Just had a quick look at the cameras - nothing about. HOWEVER, I'm travelling up to lovely Derby later this evening, so as to be at the Midland Hotel for an all day conference of a charity that happens to be centered on Derby. Can't wait to leg it down to the cathedral area and see if I see anything on site. I won't forget to check out the blue lettering on Jury's.
Sue Peregrino (who has very stupidly accidentally deleted her google account!)