Tuesday, May 05, 2009

Reel 2 Reel

Took the train up into the Lee Valley on Saturday for the Savi's Warbler at Seventy Acres Lake - only the fourth ever for the London recording area. Sleeping in (!) and the two hour journey meant I didn't arrive until mid-morning by which time it had gone quiet. This warbler has a strange cricket-like song so I decided to make a sound recording, knowing that a photograph was out the question considering its location out in the reedbed - about 80 metres from the footpath. It briefly sang around 1130h but the output from many other species including Nightingale, Whitethroat, Reed Warbler, Garden Warbler and Cetti's Warbler was still high and it was difficult to hear. I explored the rest of River Lee Country Park throughout the day, planning to return in the evening for another chance. Found around 70 species including Hobby (8+) and Marsh Harrier (imm female) and a few dragonflies including Hairy Dragonfly. Ten warbler species later I joined an assembled crowd of around 50 already listening to an evening performance of the reeler. A sound recording was a bit of a long shot but my new Sennheiser microphone managed to pick it up - ok, not a quality recording at 100 metres range, but enough to ID it on a sonogram. Continuous phrases or strophes were much shorter than the more familiar Grasshopper Warbler, typically less than 30 seconds - see the comparison below with a Gropper I recorded in Scotland a few years ago.

Larger versions here: www.fssbirding.org.uk/sonagrams.htm


Dale Forbes said...

cool sonograms.
one day I will go down that road...

Anonymous said...

No nice colourful photos of these great places and birds?! :-(


Fraser Simpson said...

Just habitat shots... no free hands to photograph and record the birds... I need my assistant for that :-)

Anonymous said...

Awww - was fun being your assistant! lol.

Greg Morgan said...

Hi Fraser

I visited Walthamstow reservoirs yesterday morning, where I saw what I think was a Savi's warbler - I took this picture

I have to admit, I'd never heard of this bird before stumbling across your very interesting blog on Saturday, though understand it's a rare visitor to these shores. Grateful for your opinion on whether it is a Savi's, or if not, what species it is.


Fraser Simpson said...

Hi Greg

The bird you photographed is a Reed Warbler (Acrocephalus scirpaceus) which is a breeding summer migrant to the small patches of reedbed around the reservoirs. Judging by your photograph, you must have been close enough to hear the constant grating/chattering song from it or neighboring birds? Savi's sounds like a cricket rather than a bird.

Features pointing to Reed in your photograph (where the colour temp looks warm or the colours are quite saturated) are: shorter square tail (longer, broader, more round-ended in Savi's); reddish-brown rump (duller brown on Savi's); large-headed appearance with fairly thick bill and steep forehead; shorter buff-coloured supercillium (Savi's pale stripe above its eye should be more obvious at this range and continue further behind the eye and Savi's also shows a thinner dark line through the eye); the pale flanks and undertail contrasting with the upperparts (Savi's shows reddish-brown flanks).

Very nice photos in your flickr galleries - are you entering the "Mind the Bird" photo competition?

Greg Morgan said...

Thanks for the ID correction, from how you describe the song I think you're right about it being a reed warbler. Incidentally I was back at the reservoirs this evening and heard a song that did sound remarkably like the chirruping of a cricket - though I didn't manage to see the culprit.

Thanks also for the heads-up about the Mind the Bird comp - if I can convince the panel that the reservoirs are within a 5 minute walk of Tottenham Hale tube station I may well enter (I reckon you could make it at a jog)!