Thursday, 12 December 2013

Pellets

Here's a photo of a peregrine pellet I found recently:

The pellet is about 6 cms. long and 2.5 cms. wide
Peregrines 'cast' pellets through their beaks from time to time to eject both feathers and bone fragments they have swallowed. They are usually fairly dry and grey in colour.
Has anyone ever seen one of our peregrines casting a pellet? (I suspect they don't cast pellets into the nest box but do this activity elsewhere such as above the nest on a ledge.
The bird makes movements which resemble coughing or choking as the pellet is brought up and dispelled.
Only rarely do peregrine pellets contain anything identifiable of interesting. Sometimes if you were very lucky you might find a bird ring inside - but, despite looking many times - I have never done so yet.
(Incidentally, bird pellets don't smell and are usually dry or dryish. Many species - especially those that eat hard objects or use grit/stones to aid digestion - will cast pellets. The species known to cats pellets include robins, rooks, bee eaters, owls and most birds of prey among many others).
You may have heard how owl pellets contain the (often identifiable) bones of the small mammal and other prey they have eaten making them valuable tools in identifying exactly what the owl has been feeding on (see http://www.kidwings.com/teacher/owlpellets/bonechart.htm.)
This is because owls eat the whole prey including the skull and fur/feathers. When the bones (especially the mammal skulls) are extricated from a pellet they can be identified to species making owl pellets a rich source of information. 
By contrast, peregrine prey is usually too big to be swallowed whole so we don't find any skulls, beaks or legs in them.....maybe a bone fragment or two but usually completely unidentifiable broken up feather remains. 
Nick B (DWT)

22 comments:

Chas Moonie said...

They don't usually swallow pigeon legs hence no rings in pellets :-)

Anonymous said...

I've seen a peregrine pellet at a distance at Aylesbury through a friend's wonderful Swarovski scope but I've never seen one up close or seen one being cast. I suspect that they would disintegrate fairly quickly? I have however found a red kite pellet. It looked like a piece of dry earth covered in grass and straw. When broken into, there was a sizeable chunk of broken bone which I assume reflects the red kite's scavenging way of feeding, it would have been taken from something like roadkill.
Whilst still watching the Derby peregrine webcam, may I recommend the Estonian white tailed eagle cam which is here http://www.looduskalender.ee/en/ (although I note it is down today, 14th December) I dislike the winter, but the WTE cam is one of the few compensations of this season for me.
I'm really devastated to hear the news from Lincolnshire Wildlife Trust about the disaster that the great storm surge of 5th December wreaked upon them.

Sue Peregrino (still needing to resurrect my google account after accidentally deleting it!)

Nick B (DWT) said...

They do disintegrate Sue - in fact the one I photoed had broken in two already....
And re. the flooding on the east coast....the N. Norfolk coast was also very badly hit which begins to beg the question - how much longer should the albeit wonderful(fresh) marshes on the east coast be protected 9at huge expense to Trusts/RSPB and the Environment Agency) when we know that sea levels are rising and that storm surges like the recent one will become more frequent? But that's a debate for another blog I suppose.
Nick B (DWT)

Phoebe said...

Thank you Nick for this post on pellets. I can see that they could easily be missed and when they break up the other birds would probably use the feathers for their nests.

I did not know that robins and rooks also produce pellets, that is interesting.

A few years ago when I visited Cathy aka 010, she produced a pellet right in front of me. I must say at first it surprised me when she started to choke, at least that is how it looked to me, then out popped the pellet. That's the first time I have ever seen one produced.

A very interesting post, thank you.

I will be looking into the robins and rooks now!

Oh and the rowan tree has been stripped of its berries during the last week. I've had some good viewing of the Redwings and Fieldfares and also a very brightly coloured male Bullfinch. What a wonderful world this is.

Lorraine said...

Have been very busy, but enjoyed reading the recent posts and links and also spotted the birds a few times over the last week or so when I've tuned in. Both look to be in good health. The female is presently on the scrape ledge.

I saw a Dunnock in the hedgerow the other day and quickly got my binoculars on it. Then I googled it and was amazed by it's far from dull lifestyle and canny methods used during it's mating and nesting period. Also it's association with the cuckoo etc.,

Now, I'm fascinated with pellets and casts, which I'm going to keep an eye out for when I go to stay at Mum's in St.Dominic (not that Mum cast's any pellets - especially as I will be making the Christmas dinner this year!) but hopefully, I'll get chance to do some walking in the woods around Cotehele.

Couldn't help but add a cute new BP image to wish everyone a very peaceful, happy and contented Christmas meanwhile!

BFN Lorraine






Lorraine said...

Oops.....

Here's the BP image I meant to add to my last post!

Lorraine said...

Tuned in to find BOTH adults on the windy tower at 13.49pm today and both appear to be fine.

Phoebe said...

Just logged in to see both adults in the scrape head-bowing with one in either side. Tiercel has now flown off.

christine said...

Just want 2 wish everyone a very merry Christmas. From Christine x

Sue Peregrino said...
This comment has been removed by the author.
Sue Peregrino said...

I've been busy too and am very behind with news. I'm out of touch with Aylesbury too and wonder if the birds are back (there have been major refurbishments going on with the building covered in scaffolding and netting - and workmen!) I've been participating in a garden bird survey and notice how slow the birds are to come back into the garden. Is this because there are less birds or because we are having such a late onset winter? There are enough feeding birds to have attracted the attention of a sparrowhawk. He's a fine fellow and I feel so honoured that he comes to my garden but it's such a tug at the heartstrings to see a little bird turn into lunch.
It's wonderful that we have now passed the shortest day but I suspect that winter will soon begin to bare its fangs.
I'm very pleased that I've managed to ressurect my google identity!
Wishing all the "peregrines and people" associated with Derby peace and light this Christmas season.

Anonymous said...

Indeed, best wishes from all the project team and let's hope 2014 brings another (the ninth) successful year up on the tower.
Nick B, Nick M and Ian L
(And thanks to everyone for keeping the comments and observations coming in during the 'off' season - a big help).

Phoebe said...



Welcome back Sue Peregrino!

I too wish everyone all the best for the Christmas season. I look forward to the coming spring and all the wonder of the wildlife it brings with it. Let's hope the winter is not too harsh.

Good to see a very alert falcon on the tower right now.

Best wishes

Phoebe

Helen said...

Both peregrines around this morning, with some calling and head bowing taking place.

Lorraine said...

He's asking her what she want's for Christmas this year - and she's saying she'd like one of those " 3 in 1 " birds from Tesco instead of a glazed partridge !

The falcon has " stopped over " on the tower quite a few times lately, often up near the cam and well into the early hours.

I hope to tune in as the bells ring in 2014 - wouldn't it be great if one of the birds were present !!

No one home presently though
Tues 12.25pm

Helen said...

Some lovely views of a peregrine on the tower right now. It looks like it's sheltering from the wind tucked in close to the camera. There's a lot of preening taking place too, perhpas after being so wind blown!

Hilary, B'ham said...

I have just been watching the 2 Adult Peregrines at Nottingham University and one of the Adult birds at Norwich Cathedral with ease and clarity. Only a dirty camera 1 and a static camera 2 has been available for some time at Derby. Are there any plans to upgrade/repair our cameras at Derby? Can anyone in the project team let us know what is happening? I do travel the 90 miles return to Derby regularly to get (not always) a sighting of the Derby Adults. I for one would be happy with one live, functioning, clean camera picture instead of only a murky camera 2, not live available. It seems to be happening at other sites so why not Derby? How much would we need to get one good camera, live and cotinually functioning up and running?

Nick B (DWT) said...

Hi Hilary: sorry but we have no immediate plans to upgrade the cameras though you may recall we added the wide angled view cam last spring. The dirt on that lens was caused by the chicks last summer but the only way to clean it is to abseil down....which will be done in six weeks or so when the annual clean and nest/camera check is done. The quad view is the same as it has always been I think. Nick M is terribly busy with all sorts of things at the moment but he tells me he will try to get up the tower one day soon and check everything. He won't be abseiling though just yet!
We did decide not to keep paying for the Outersight camera feed during the off-season because it is quite costly. We are having a meeting in January and will discuss your comment then. Probably not a terribly satisfactory response but, given limited resources and pressures of other work (like trying to save an urban nature reserve in Derby from development), peregrines have had to take a back seat recently. We'll keep you (all) posted.
Nick B (DWT)

Nick B (DWT) said...

Following Hilary's comment (and a brief discussion with Nick M today) we are inclined to think Hilary does have a valid point. NM and I plan to meet up in about two weeks time and will discuss how to improve the views. One option would be to reinstate realtime on the wide angled camera in the nest platform, another to do a 'quick' abseil down to clean the offending lens (though that depends on the weather and having a free half day).
We'll keep you all posted....
Nick B (DWT)

Sue Peregrino said...

I hope all we Friends of Derby Peregrines have had a peaceful Christmas and will have a Happy New Year. I'm content to carry on with the cams as they are until it's time for the annual platform clean. I know there are so many issues going on in Derbyshire, including trying to Save the Sanctuary and stopping DEFRA in their bid to exterminate badgers. Notts WT must be getting huge help from Nottingham Trent University and Norwich is run by the Hawk and Owl Trust. DWT is, I am sure, using their resources as best they can. Two dodgy cameras is 100% better than we are getting at Aylesbury (which is zilch) I don't think we even have the birds any more as the building has been swathed in scaffolding and netting for at least 5 months now while building remedial work has been carried out. If you get Nick Moyes abseiling down Derby cathedral especially to tweak the cameras, I think you'll owe him big time, I couldn't abseil down there for all the tea in china! (I'm a coward) Sheffield has a big piece of my heart so I'd want to sing their praises but it looks as if they're another place with the cams off at the moment. All in all, I think Derby may not be the best but it's certainly not the worst.

Helen said...

I've added a couple of new screen shots to the Flickr site which were taken recently - www.flickr.com/groups/derbyperegrines
One shows a lovely glimpse of the peregrine's feathers from below. They really are stunning! It's great to be able to see them on the cameras.

Lorraine said...

Just been watching the female via Cam No2 as she was checking out the egg laying area inside her scrape, testing it for fit and comfort etc., and then a close up shot of her from Cam No1 showed she seemed quite satisfied with it's potential, ready for next year. She's now moved onto the scrape ledge and seems happy with the little cleared area she's keeping a notable watch over lately.

Cam No3 is still working on and off ( last operating at 7.42am this morning for instance ) and sometimes I've been lucky and managed to tune in and get a few moments live action in between it's frozen periods.

I do hope nobody takes any risks to try to remedy the present situation though, because we can still get plenty of visual assurance that both adults are in good form ready for the start of the new season. A few more weeks will find the scrape refurbished and the lenses all cleaned anyway, in time to accommodate the extra viewing figures that will be tuning in to watch any signs of courtship activity between the adults prior to egg laying. Six weeks will pass by in a flash, so, though a little frustrating on occasion, I personally don't mind the restricted viewing at present, which serves well to confirm the birds are both on track.

The new flicker shots from Helen were nice to see ( many thanks! ) and the bird she mentioned that was sheltering up close to the cam the other night,( 27th ) remained there, snug and content, well into the early hours.

Whilst staying over at my Mums, we spotted a young (and very healthy looking) badger in the garden one night and were able to watch it clearly for some time in the garden floodlight. I was surprised when it turned it's nose up at one of Mum's home made mince pies though, and our laughing, which we just couldn't suppress, sadly caused it to scarper back down into the woods !! Went for a short walk after dinner, to Cotehele woods, but didn't find any pellets, but made friends with dozens of cute dogs out for a frolick with their owners before returning back to Mums very muddy but very happy !

Oh well, the falcon has now left the scrape and has re-located right up close to the cam on the tower ledge.

Will tune in again later's.......

PS: Sue, I also, noticed there were very few birds coming to feed in Mums back garden, which is strange, as you mentioned. But did see the little wren many times bobbing about and looking just lovely. I do hope my nest box attracts it's attention next Spring !