Acro's & Locustella's: Warbler Sound Quiz Answers

The answers for last weeks sound quiz , if you missed the quiz just scroll further down the blog. Also a big thankyou to John Miller, Paul Ash and Gary Thoburn for supplying the stunning photographs. 

1. Sedge Warbler: A very excitable songster that sings erratically with lots of ‘fast mimicry’ – it can impersonate many species but these calls are always delivered quickly and in amongst their usual buzzy repertoire. Easily found in the right habitats in Cornwall; particularly reed beds, lake margins and wet meadows and it can even nest in mature hedgerows. Sedge Warbler is also a regular spring migrant and can be found singing along the coast, especially in sheltered valleys.
   
2. Reed Warbler: Delivers a fast-monotonous song that sounds superficially similar to Sedge Warbler but it has more rhythm and tends to repeat notes before moving onto a new noise without a break in the song.  Not as widespread in Cornwall as Sedge Warbler owing to the fact it tends to be restricted to Phragmites Reed when breeding. However, if you visit the right habitat anytime from now onwards you will stand a good chance of hearing one singing. As a migrant Reed Warbler will sing from less typical habitat particularly in coastal areas up until early June when the last returning birds arrive.
   
3. Blyth’s Reed Warbler: This Acro has an interesting song quite unlike that of Reed Warbler being more similar to Marsh Warbler to my ear. The song is given at a steady pace but it has a ‘stop, start’ feel to It with several notes uttered in succession followed by brief pauses. They can mimic species well and produce a whole variety of rattles and tunes but to my ear at least the song seems to have a rather mournful quality at times with down slurring whistles repeated throughout the song in most instances. Blyth’s Reed Warbler is expanding its range into Western Europe and I expect more singing males to be found in spring across the UK in the next decade. In Cornwall the only records come from the ringing mecca of Nanjizal Valley (where they have been annual during Autumn in the last few years with one late spring record) so I believe they pass through other parts of West Cornwall undetected due to their skulking nature. Birders should be mindful of Blyth’s Reed Warbler in late spring (they are a late migrant which tend to arrive on their breeding grounds from mid to late May onwards) in meadows and coastal valleys with good cover. They are not really a reed bed species and tend to favour lakesides and swampy habitat in which to breed. 
   
4. Marsh Warbler: Marsh Warbler is of course well known for being an outstanding mimic of other species. In fact I don’t think any other warbler can imitate as many different species. I’ve read many times that ‘if you hear several different birds singing from one bush then it is probably a Marsh Warbler’. I do think that’s a little bit misleading as so many warbler species mimic other species well. But the sheer variety of different calls within the song, as well as the fast pace and ‘squeeky toy’ sounds make it a distinctive song. In the UK Marsh Warbler is a rare breeding bird with a declining population and it is also a very scarce migrant. In Cornwall it is a rare migrant but does turn up in late spring from time to time. A passage bird is just as likely to sing from a mature hedgerow or the edge of a wetland than from a reedbed margin. It’s worth knowing too that Marsh Warbler is a late spring migrant with early June being a particularly productive time for one to occur.
   
5. Song Thrush: A trick question! But an important species to learn and be confident with in regards to its song when ruling out other species. A loud singer which pretty much always repeats the same note three or four times, followed by a brief pause (almost as if it’s taking a breath) before singing another three notes. Song Thrush will mimic most species remarkably well as well as mechanical noises which it may have heard in the past. They will occur in most habitats and I have heard them singing from reedbeds and scrubland alongside Acro warblers. They will also sing very early in the morning before sunrise and commonly sing after sunset in spring. 
   
6. Nightingale: Another trick question! The Nightingale has perhaps the most famous song bird of them all. Its magical song is full of scratches, whistles, trills and mimicry. It could well be found in similar habitat to all of the species in this quiz (although in Cornwall it is a county rarity and far from annual in appearance) and a singing bird on migration could cause confusion. Listen out for it’s typical notes as the male starts the song it builds up in speed and then often finishes with a very fast rich rattle (listen here). Similar in style to a Song Thrush it then often pauses for a split second (which can feel longer) only to begin again. Nightingale can’t really be looked for in Cornwall but it certainly can be hoped for over the years for any diligent patch birder or during spring migration. I have found three singing males and they have always been a complete surprise.
   
7. Great Reed Warbler: This species sounds ‘big and clumsy’ a bit like how it looks! The song is rather loud and lower pitched than other Acro’s helping it to stand out in the reed-bed. It starts at a slow pace and often stops again after a couple of seconds; the repertoire of notes never sounds so extensive to my ear with the main phrases sounding rather croaky in tone.  A rare vagrant from the Continent however a singing male in Spring is the most likely way of getting this rarity on your self-found list. Best hoped for in reed-bed habitats such as Marazion Marsh perhaps, however they do occur on migration (abroad at least) in very small ditches and scrub patches so perhaps it should be on birders radars elsewhere.
   
8. Grasshopper Warbler: This may well be the only Locustella you ever hear singing in Britain as the other two examples in the quiz consist of a rare migrant and a rare vagrant. However, Grasshopper Warbler will often sing from a reed-beds (like Savi’s) and can favour swampy ground similar to the habitat a singing River Warbler could turn up in (if only!) so knowing it intimately is important. The main things I notice is that it is slightly less ‘clear’ sounding compared to Savi’s Warbler and the diagnostic part for me is that the song changes in pitch regularly, Savi’s and River Warbler sound more monotonous from my experience. This species is sadly declining but it can be found in Cornwall on un-spoilt moorland, meadows and crop fields. It sings more frequently early in the morning and again late into the evening.
   
9. River Warbler: The song of the River Warbler is typical for a Locustella warbler; a continuous buzzing drone which is shared by all species of this family group. However, its song has a very subtle disyllabic quality (I liken it to a water pump or a cricket) and the tone of the song is constant and never changes its pitch (such as Grasshopper Warbler will.) River Warbler is a rare vagrant to the UK in spring with very few records but it could well turn up in Cornwall. It favours swamp like habitat and acidic bogs in its home range so perhaps one day it’ll be a dream find for somebody in the Lizard area, Goss Moor or Bodmin Moor.  
   
10. Savi’s Warbler: The whirring song of the Savi’s Warbler has a rather mechanical quality to its song, which is monotonous and ‘dry’ sounding. The pitch doesn’t change throughout and it always sounds rather clear in quality. Savi’s Warbler is a rare spring migrant to the UK with small numbers arriving from April on wards in most years. In Cornwall it is a county rarity and I believe the last record was ten years ago at Marazion Marsh.