The spring migration has been well underway for a few weeks now and it has brought many interesting species to our shores, but why come all this way? Most of our warblers come from the Mediterranean and Africa where they have sheltered from our cold, harsh winters, but now that our climate has changed with the seasons, the higher rainfall coupled with plenty of sunshine causes lots of lush vegetation to grow. This feeds insects (which feed the warblers) and gives the birds plenty of suitable song-perches and nesting spots!

The most obvious warbler for many, and the one that arrives first and sings first, is the chiffchaff. Leaving countries like Morocco at the end of February or the beginning of March, ‘chiffies’ often take just ten days to reach us (interestingly flying in 50km bursts) and immediately set about singing their name! If you stop to listen, you can often locate where their call is coming from- when they first get back there are few leaves on the trees and you should be able to catch a glimpse of them shuffling about as they sing, if you are patient. They often will be looking for food at the same time as singing- multi-tasking warblers!

It is not much longer before the blackcaps join the chiffies, and this time the two sexes look different- males have a smart black cap atop a grey body, and the females have a warm chestnut cap instead. Where your local blackcap has come from depends on where you are in the UK- on the southern coast of England and in Ireland, you will be hosting birds from the Mediterranean, whereas in East Anglia, the rest of England and Scotland your bird is likely to have migrated westwards from the colder countries of Europe. At Lackford we heard the first blackcap of 2020 on 25^th March, and their song is more imaginative than the chiffchaff- a fast and showy warble with a flourish at the end, which helps to distinguish it from the next warbler we will look at which has just arrived- the garden warbler.

Telling these two warblers apart by song isn’t easy, and we are currently getting towards the end of the helpful two weeks or so between the blackcaps arriving and the garden warblers reaching us! The song of the garden warbler is a bit faster than a blackcap, more steady and with no flourish at the end. It is usually sung a little quieter, from deeper within a bush and this can make the birds tricky to see. When you do see them, look for a plain, greyish-brown bird with no distinct markings. Garden warblers prefer more wooded settings, or the thickest hedges to live in. At Lackford the first garden warbler was recorded yesterday, on 18^th April, which brings us up to the present in the timeline of migrants…

While the warblers we have looked at so far tend to live in scrub and woodland, there are two warblers you are only really likely to hear in reedbeds- sedge and especially reed warblers. Sedge warblers are just arriving as we speak and are a bit more flexible in where they live- sometimes you can find them in wet stands of willow with just a handful of reeds nearby whereas reed warblers are much stricter and need areas of pure reedbed to live in. Sedge warbler numbers are building day by day at the moment but we are still waiting for the reed warblers… any day now!

To me it always sounds as if a sedge warbler is having an argument with itself! The song has a few scratchy notes and is pretty frantic, whereas a reed warblers’ is slightly gentler, slower and more regular. I think a lot of the notes sound like a rubber-soled shoe squeaking on a shiny floor. Reed warblers look a bit like garden warblers- plain and reed-coloured, whereas sedge warblers are a lovely complex pattern of darker brown streaks and bars on a reedy-coloured body. It is tricky to sneak a look at one but sometimes you might catch them moving through the reeds in search of food, or singing near the top of a reed stem. It won’t be long before we can hear reed warblers, but like the gap between chiffchaff and blackcap arriving, we are in the gap now between sedge and reed warblers reaching us.

Looking to future weeks, we can also expect to hear whitethroat and lesser whitethroat in the wilder, quieter parts of our countryside. Both these species are lovers of dense bramble and hedgerows. To tell them apart is tricky as both are small with a white chin and a grey head. But the whitethroat is a little larger, with warm brown wings on a lighter brown body- the wings often stand out as a different colour if you get a good look. The body of a lesser whitethroat is a similar grey to the head, and they sound a little different too. Whitethroat deliver their song in repeated tunes that each last about a second, and always sound the same. They never vary from this, making them an easy one to learn and quite different from the other warblers we have looked at. Lesser whitethroats also sing in batches, but their song tends to have a fast trill at the end and is a bit more like a sedge warblers’ scratchy song for the first half. Interestingly at Lackford, lesser whitethroats are more commonly recorded than common whitethroats- probably due to the habitats on offer suiting lesser whitethroats really well.

While you are listening for these warblers out on your walks, there are two final songsters you may hear if you are lucky. The willow warbler is one- they look just like chiffchaffs but with pale legs (chiffchaffs have dark legs) and they have a beautiful, liquid, fluty warble delivered often from willows, giving them their name. It is a repeated tune, like the whitethroats they never sing anything else.

Last but certainly not least, in terms of their beautiful, incredible song, is the nightingale! It is not actually a warbler but a chat, so in the same family as robins, stonechats and redstarts. They are already singing at Lackford, heard first this year on 9^th April. The males deliver their mind-blowing song all day and often through the night too, until they attract a female to their deep scrub hideout. They are difficult to see because they really bury themselves in vegetation! While not a warbler, it wouldn’t be right to mention the birdsong at Lackford at this time of year without including the nightingale.

I hope this blog has highlighted what you might see out on your local walks and has helped to unravel all the warblers from one another- it can be a bit overwhelming if you are somewhere where they all decide to sing at once. While we ask that you only go to Lackford Lakes to hear these birds if you live within walking distance, you should be able to find quite a few of these birds in local green spaces too. After all, all a warbler needs is some thick scrub and plenty of caterpillars!