Learning to ID warblers

A few weeks ago I went to Brandon Marsh and bemoaned the fact that I couldn’t tell the difference between a reed warbler and a sedge warbler.  Fortunately I had already booked myself on a course to learn to identify warblers that was run by the local wildlife trust (Beds, Northants and Cambridgeshire).

So, I set my alarm for 5am this morning so I could get up in time to meet the instructor at 7am at the lovely Summer Leys reserve.    Despite the gloomy weather forecast, the sun was shining and the sky was blue (although it was still a bit chilly) as I joined 12 other people hoping to be able to tell their Sylvidae apart.

Fortunately for those of us in the middle of the UK, there are only about 10 warblers that we are likely to encounter which is just as well because they all tend to be somewhere on the spectrum between grey and olive passing through brown.  Out of these, the grasshopper warbler is distinctive in song, and tends to just pass through the area (which I didn’t know) and the Cetti’s warbler (new to the UK since the early 1970s) has an explosive, loud burst of song.  Hmmm, I need some practice at birdsong recording methinks.

The main goal of the course was to be able to tell four groups of similar warblers apart; willow warbler and chiffchaff (look almost identical, but sound completely different), garden warbler and blackcap (look different, sound very similar), reed and sedge warbler (look different, superficially sound the same, but difficult to see), common and lesser whitethroat (look similar sound very different).

We were lucky enough to hear and / or see eight out of the ten warblers; unfortunately we didn’t find a lesser whitethroat, a bird that I’ve never seen before.

We started with a walk around the reserve, which was filled with birdsong, and some less tuneful birds like the gulls and greylag geese.  Even better, there weren’t that many people about.  After nearly two hours we headed off to see some pictures and hear some recordings of the birds (the BTO website has some brilliant ID videos) before going back to see if the birds were still singing.  (Some were in exactly the same spot, but the road noise was horrendous, even though we were in the middle of nowhere).

So, am I now wise in the ways of warblers – other than the lesser whitethroat, I think I am.  I heard the willow warbler (unfortunately I didn’t get a good recording of it)

– and now I wonder if I have been hearing them all the time, but mistaking them for chaffinches.  They really have a lovely song – the instructor likened it to a falling leaf.  I will have to go out and see if I can find one in the local country park.  I think I can tick these two off my can recognise list.

Sedge and reed warblers – this was trickier at first, but there is a big difference in the pace and the complexity of the songs – the reed warbler is quite plodding whereas the sedge warbler is more frantic with lots of whistles and changes in pitch – they also sing in the air as well and are found away from the reeds, usually in scrub, unlike the reed warbler.  So, I will have to go back through the recordings I have made at Barnes Meadow and go back to Brandon Marsh, but I think I have these two sussed as well.

Common whitethroat – much shorter song and I think I can visually recognise one.

Blackcaps and garden warblers – probably the trickiest and at times the instructor couldn’t say for certain.  However, the blackcap, to me, sounded as though he knew he was going to finish, whereas the garden warbler just garbled on for some time before stopping.  Besides, they look different and, although we saw one garden warbler during the day, we saw a lot more blackcaps – they are much showier.  I think I am on about a 90% confidence with these.  I just have to learn their other calls, as I didn’t realise that it wasn’t only the blackcap that makes a noise like two pebbles being bashed although to my ear the garden warbler call sound was more like a squirrel than a pebble.

In the end we saw a Cetti’s warbler (very rarely seen and a first spot for me), reed and sedge warblers (so now I have seen a reed warbler, although only briefly), blackcap and garden warbler (my second ever garden warbler, the first being last weekend during a run), heard a willow warbler, saw and heard a chiffchaff and saw and heard a couple of common whitethroats.  Stick in a little egret and about 8 hobbies and I would call that a good morning’s birding.  Oh, and yes, I think I can say that I can now ID warblers (most of the time).

So, the moral of the story is, get up early and go out listening, then stand and watch.

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