Pallas’s Grasshopper Warbler- lord of the locustella’s

Posted by Brydon Thomason on Saturday 9th October 2010 | Birding in Shetland

Without question Pallas’s Grasshopper warbler is one of the most sought after of Siberian vagrants to reach Britain, or indeed Europe. For many determined ‘listers’ and seasoned rarity hunters it is a dream find. At last this year, my luck was in and my time had come!

Searching for rare locos in autumn is one of my main ornithological objectives and draws me to search the ditches, marshes, Irises and Canary- reed grass beds every year. This has indeed worked for me on more than one occasion for Lanceolated warbler but for the ‘lord of the locos’, AKA ‘PG Tips’, I had to be a little more patient before I would find my own.

Accompanied by James McCallum and with my 11 month old son, Casey, strapped to my back, we had almost finished working a lush network of Iris beds and Meadow sweet when out it came. Its first flight was a short one, silhouetted against the sunlight. Its long tailed appearance and largish size was enough to excite us both as we took a few steps towards where the bird came down.

As we cautiously closed in it took flight once again. This time its striking plumage tones were remarkably obvious. James and I looked at each other in disbelief. Its bright, yellowy-buffy olive toned underparts, very warm chestnuty, rufous toned rump contrasting distinctly with the longish and very dark tail, were already enough for us to know what was in front of us. “Why wasn’t that a Pallas’s Grasshopper Warbler?”, James rather gleefully and sarcastically asked, knowing full well, as I did, that it clearly was one.

The next few seconds were amongst the most surreal birding moments of my life. We edged excitedly closer, brimming with anticipation, to where it had landed along a well grazed fence line, determined to get ‘on the deck’ views without flushing it. Casey then decided to rather cheerfully remind me he was there! His happy but rather loud vocalisations (baby banter) had me thinking the bird was sure to fly. But at the same time I found the whole scenario completely bizarre and yet so very special to have him with me at such a momentous occasion. I glanced at James who I was pleased to see by his expression was amused by his antics.

Eventually I was in a position to see the bird crouching on the ground in full view – a pristine example of a first winter autumn PG tips – it was ‘in the bag’! I carefully side stepped away from the bird and out of view of it and gestured over to James (who was just out of view of where it sat) with a few celebratory punches into the air, “Get in – we’ve done it!!” Along with a couple of obligatory rare bird finding expletives of course.

But no matter how obvious the bird was to us there and then, we had to make sure to note all the key features and hopefully secure some photographs. With this in mind I speedily returned to the car to grab my camera.

As with acrocephalus warblers, locustellas can be very difficult, especially as their skulking nature can make it hard to assess key features in the field. Although it was never an issue with this bird, Grasshopper warbler has to be eliminated if you find an autumn loco and it’s a good starting point to assume that’s what a bird is most likely to be, rather than assume it to be rare because its Shetland as many people do! These are the main key features we noted to confirm its ID;

  • Overall largish size and structure with longish rather heavy ended tail.
  • Plumage was very contrasting looking overall.
  • Underparts strikingly bright buffish olive toned, completely lacking any streaking especially on undertail coverts where cleanest.
  • As mentioned above, very dark blackish rounded tail contrasting markedly with the warm chestnut-rusty toned rump then darkly and well defined streaks on warm toned mantle leaving a fairly plain nape.
  • Crown distinctly dark-capped with well-defined clean yellowy-buff supercillium with a yellowy wash from face onto throat.
  • The tertials (and primaries) were quite dark blackish as was the tail and were neatly and distinctly white tipped with each having a tiny crisp-white tip. The tail too showed neat restricted white tips. These two features being of course where it gets its nickname of P-G-Tips!

Away from Fair Isle (where it is something of a speciality with 21 records to date) there have been 14 in Shetland and just eight records from the rest of Britain.