Willow Warbler © Mark Lewis

It can still be chilly in April and sometimes it can feel like we’ve skipped summer and autumn and gone straight back to winter… The migrants will battle forth regardless, against the weather, but there may be impacts from a cold spells. It can delay arrival dates, suppress insect activity which makes it harder for a lot of our newly arrived migrants to get into breeding condition, and ultimately if it’s cold enough, it could even spell disaster for some individuals. However, the majority will still make it, so who is going to be arriving next?


Perhaps the most iconic summer migrant of all will be arriving soon. One swallow may not make a summer, but I’m guessing it will be making someone’s day at the beginning of April, most likely somewhere in southern Scotland. Early April sees this species arrive en masse here, but also look out for House Martins as well. The bulk of our breeding House Martins will arrive later in April, but gatherings of hirundines (swallows and martins) may well encourage an early arrival to linger. If you are interested in seeing how species such as Swallow and House Martin spread across Europe at this time of year, have a look at these great interactive maps generated by the EuroBirdPortal. The map for Swallow can be found here and House Martin is here and from there you can browse for distribution maps for hundreds of different European species. Isn’t the internet wonderful!

Another species that will be arriving sooner rather than later is the Common Sandpiper. This species breeds in upland areas and has a characteristic way of bobbing along faster flowing streams and rivers. However, on migration they can be found in a variety of wetland habitats and are less restricted to upland areas. Listen out for their distinctive calls along waterways and inland lochs, or even as they migrate overhead during the night – you can hear a selection of their high pitched, whistling calls here and here. In spite of this species having the word common in it's name, it is amber listed in the UK due to the severe declines in its breeding population. As such, any record of Common Sandpiper, but especially those in suitable breeding habitat, would be very useful.

Having ‘our’ warblers spend the winter here is becoming less unusual, but still the majority of them move away from our hard winter climate. Blackcaps winter in small numbers here but will be arriving back into Scotland in big numbers by mid April, with the first arrivals at the beginning of the month. At first, they are likely to give themselves away with their loud, rich songs, an example of which can be heard here. Their song always puts me in mind of a blackbird in a hurry! There’s not much out there that sounds a lot like a Blackcap – that is until the Garden Warblers arrive, as the two can sound very similar! Luckily we don’t need to worry about that until mid May, which is when the first Garden Warbler territories will be defended in Scotland.

Our Curlews are already on the move, heading from our coasts and estuaries back up to higher ground, or perhaps back over the North Sea to breed somewhere in Scandinavia. Their close relative the Whimbrel will also be moving as well. Their journey is a longer one, as having spent the winter in Africa, they will be passing through Scotland over the first half of April on their way to breeding grounds at much higher latitudes. There is a small breeding population in Scotland, almost exclusively in Shetland these days, but the vast majority of birds that are seen in Scotland in the spring will be heading elsewhere. Separating Whimbrels from Curlews can be a bit of a headache as they are generally very similar in appearance. The Whimbrel has a shorter and ‘kinked’ bill compared to the longer and more smoothly curved Curlew, and the Whimbrel has a more well marked head pattern, with a more contrasting eyestripe, and a dark crown that is neatly divided by a thin pale stripe. Whimbrels also have a very distinctive call, with its series of short whistles sounding quite unlike the ‘cuuurl – EE’ of the Curlew. You can hear a nice example of a Whimbrel’s call here

Something else moving towards much higher latitudes to breed is the Iceland gull. Traditionally this has always been considered to be a winter visitor, but away from favoured harbours, you’re actually a lot more likely to come across one in early spring, as it meanders its way northward. It’s a pretty uncommon bird but once you have your eye in on its pale plumage, and especially its pale wingtips, they can be very easy to pick out among the commoner species of gull, although Glaucous Gull will give you something to think about when identifying one, of course. With juvenile birds, think biscuits. Iceland gulls tend to be Rich Tea colour or paler. If you get something that looks more Digestive, it’s much more likely to be a Glaucous Gull. Naturally, coasts and especially harbours where fish are landed are the best places to go and look for them, but with at least three different immatures inland in Scotland this week, they can turn up anywhere.

And finally, one to one of our most iconic summer visitors. The first Cuckoos should be reaching us by mid April so when it’s warm and the wind has dropped, it may be time to start listening out for that distinctive song, especially in south western areas. Many will still be in Africa but the first few will be on their way across Europe or even England. Tracking projects run by the BTO have opened our eyes onto the wintering grounds and trans-Saharan migration routes of ‘our’ Cuckoos (seems strange calling them that when they’re only here for four or so months!) and you can keep up with the journeys of the current pool of tagged birds here. The Cuckoo is a declining species so records of them will be appreciated by your Local Bird Recorder. You can read a little more about their decline here

Birding always used to be called bird watching, but I think one of the reasons that the name birding has stuck is because it acknowledges the role that our ears play. In fact, there are plenty of birds that we might not see at all, but can recognize by their distinctive sounds. Several ‘wetland’ birds fall into this category (Bittern, Water Rail and both crakes, for example) and another one of these is a summer migrant that will be arriving into Scotland towards the end of April. If you’re enjoying any wetland edge with thick vegetation (or even any thick, grassy habitat) at this time of year, keep an ear out for a Grasshopper Warbler. These birds can be incredibly elusive (although in contrast, if you do find one they can sometimes show very well) but where they are present, they give themselves away with their ‘reeling’ song. You can hear a nice example of that here. It’s called ‘reeling’ as it has been likened to the sound a fishing reel makes, and the bird’s name is also a result of this song, which is similar to the sounds some species of grasshopper make. I guess we should make our minds up which it sounds like and stick with one!

A more visible summer migrant (and dare I say it, a slightly better looking one…) is the Common Tern. Common terns arrive  in Scotland slightly early than the very similar Arctic Tern, and they are a little different in their habits. Arctic terns are exclusively coastal species in terms of their breeding, and although small numbers may pass inland, an inland ‘commic’ tern (that’s the name given to this species pair) is much more likely to be a Common. Unlike their Arctic cousins, Common Terns will breed on inland lakes and islands in rivers, and have even nested on the rooves of industrial buildings near rivers. A sure sign that a Common Tern is heading to an inland nest is if you see one carrying a fish away from the sea.

In April, we’re still very much in the period of exchange. We have plenty of summer visitors arriving of course, but we also still have some winter visitors left to depart. It’s worth remembering that these birds are still around, and can sometimes be encountered singing a song that’s unfamiliar to us. The most likely of these would be the Redwing and the Brambling. Redwings will still be passing over during the night – a great one to listen out for on your way back from the pub!

What might be the cherry on time we start seeing the first Swifts arriving into southern Scotland. Obviously they will arrive in greater numbers through May  but some of you may be lucky and see one earlier than this. There are few birds that scream (literally!) migration like a Swift does – built to move, arriving late and leaving early. Their time with us is fleeting, yet later in the year they really make their presence felt, screaming along our streets and over our houses as dusk falls, having what one can only assume, is a good time. We experience swifts as a shape in the sky, for the most part. There is little plumage detail to see, but what is there is rendered invisible by the height, speed and agility of their flight. They are mysterious, and declining, and if you are lucky enough to be blessed with Swifts around you, do look out for visits to nests later in the year. Records of nesting birds would be particularly useful to your local bird recorder.

The Whinchat is everything the swift isn’t. Dapper - colourful and exquisitely patterned, often motionless, and unobtrusive. They will have made similar journeys to the Swifts that are incoming (although from less far south in Africa), but one can imagine in a very different manner – either skirting around the coast of West Africa or flitting across the Sahara, one oasis at a time. When they arrive here they will head into the lowlands of the uplands, if that makes sense, breeding in valleys with scrubby vegetation and bracken. As I seem to say a lot, this is another declining species, and hopefully you know the drill: Report, report, report!

And last, something of a longer shot, unless you’re in the south east of Scotland. Yellow Wagtails are rare, but perhaps increasing visitors to Scotland, and can be found from late April  through to later in the spring. Birders up here like them for several reasons. They’re rare, which gives them value, and they look brilliant too (we are human, even if we don’t always make that obvious! ). As if this wasn’t enough, they also come in lots of different guises too, depending on what part of Europe they are from (and I guess, are supposed to be heading back towards). ‘Our’ birds are brilliant yellow with greener upperparts. Birds from the bulk of the European mainland are known as ‘Blue-headed Wagtails’ (I’ll let you work out why…) and a little later on we may see Scandinavian breeders known as ‘Grey-headed Wagtail’. There are many more options – these are just the most numerous visitors. What makes them even more complicated, or interesting, depending on your point of view, is that the different forms can hybridise with one another. When our birds meet Blue-headed Wagtails, they make little baby ‘Channel Wagtails’, which have the most delicate powder blue heads (and I think are the best looking ones, although I’d be happy if I looked as good as any of them…). Look out for them on lowland coasts, wetlands, and fields with livestock in them.