April arrivals
MIGRATION should be in full swing this month, with hopefully many enjoyable days on the local patch to come. Every day is different in April – you never know what might appear! With so many species on the move and variable weather conditions, migrants could pop up anywhere, and for both coastal and inland patches this is a good month for passage waders and seabirds. There is also the potential for overshoots, especially later in the month.
Species: Arctic and Common Terns
Both of these tern species are long-distance migrants and will be passing through from early April on their way to breeding grounds in the UK and beyond. Sadly, terns have been impacted by bird flu so it’s hard to know what the numbers will be like this year, but fingers crossed the picture won’t be too bad – and that they will have a successful breeding season. As well as being recorded flying by during seawatches, Common and Arctic Terns often appear on inland waterbodies during migration, so it is well worth keeping them on your radar. Drizzle or persistent rain throughout the day could result in a flock appearing and lingering to rest or feed until the weather clears, especially if combined with a north-east wind. So, keep an eye on the weather!
Weather: fall conditions
Spring migration is especially exciting if you witness a good arrival of migrants, often deemed a ‘fall’ of birds. To see your local patch dripping in warblers or watching a flock of waders suddenly drop down during a rain shower is quite something! Clear conditions along the north coast of France and across the English Channel are helpful, whereas a large amount of persistent rain is likely to block most movement. Southerlies and south-easterlies coming up from the Continent also encourage migration, as can high pressure. For us British patchbirders, calm and overcast conditions should result in an arrival of migrants such as the common warblers, and perhaps chats and Ring Ouzels. Drizzle and light rain can have similar results and it’s always worth returning after rain as migrants are constantly arriving. I’ve had mixed results with fog and mist, but it can ground migrants which then tend to appear once the sun breaks through. Frustratingly, it usually burns off and improves just as I’m heading home for work! The blogs by bird observatories such as Portland (www.portlandbirdobs.com) often discuss the weather and provide useful insights into the best conditions for look out for.
Habitat: scrub
Scrub is sometimes demonised as being untidy, but it is an important part of grassland habitats, providing cover, food and many other benefits, and is well used by birds. From a birding perspective, hedgerows and gorse are equally useful and well worth scanning carefully for newly arrived migrants and signs of breeding alike. Species to look and listen out for include the common warblers such as Common and Lesser Whitethroats, Garden and Grasshopper Warblers, Whinchat, Common Redstart and European Turtle Dove. Common Nightingale is another species which favours scrub, particularly on woodland edges, and has a super song. Raptors and owls also make use of scrub and hedges – it’s possible in April that young
Tawny Owls could be hiding in hedges or ivy-covered trees.