BTO migration blog

Spring and autumn are exciting times for anyone who watches birds. Here on this blog we will make predictions about when to expect migrant arrivals and departures, so that you know when and where to see these well-travelled birds.

Friday 9 May 2014

World Migratory Bird Day

This weekend sees the celebration of World Migratory Bird Day, an initiative that seeks to raise the profile of migratory birds across the world.

Cuckoo by Steve Ashton

Migration is probably one of the most hazardous things that any bird may undertake, our satellite tagged Cuckoos are testament to that. We have lost birds to bad weather; Martin the Cuckoo was caught in a severe and unseasonal hail storm in southern Spain in spring 2012. Other birds have been defeated by the extremely arduous crossing of the Sahara, whilst some found it difficult to fatten-up during the wet, cold 2012 summer here in the UK, hampering their progress south.

This spring seems to have been good to our Cuckoos and currently seven tagged birds have made it back to the UK, three to Scotland, three to East Anglia and a single bird to Dartmoor, almost at the exact location where he was tagged in 2013. Two birds are still on their way and are in France and Spain but we have lost two birds on the way. One, Tor, is almost certainly down to tag failure, his transmissions had become patchy during the winter, and the other, Ken, as he was preparing for his northward crossing of the desert – maybe he just couldn’t find enough food, or perhaps he was taken by a predator, we will never know for sure.

There are plenty of natural hazards but many migrants also have to run the gauntlet that the modern world throws at them. Chris Packham recently highlighted the plight of European migrants as they migrate through Maltese airspace, read more here. A small number of British migrants also use this route and 29 recoveries of birds ringed in Britain, of 14 different species, have come from Malta. Among these have been two British-ringed Cuckoos; indeed two of our satellite tagged birds have flown directly over Malta on their way to Congo.
Black Kite by Jill Pakenham

Whilst many birds perish during migration, many successfully make it back. The weekend just gone saw the mass arrival of Swifts to the UK, the first wave of Spotted Flycatchers and the first Nightjar. There was also a good showing of southern overshoots, with multiple arrivals of Hoopoe and Black Kite, and several species of warbler, including a singing Eastern Bonelli’s Warbler in Northumberland.

The weather over the next few days will make it difficult for migrants to move. Strong winds and heavy rain is forecast to give way to light winds and warm weather for the latter part of the week and if this is the case we could see birds moving in force again – the spring is getting on and there will be a sense of urgency to get to the breeding grounds for these later arriving birds. More Spotted Flycatchers, Turtle Doves, Nightjars and House Martins should take advantage of any windows in the weather.

Scops Owl by Peter M Wilson

From mid-week we could see more overshoots but we are coming into the period where anything could turn up. An obliging Scop’s Owl would fit the bill, but given the Atlantic lows during the early part of the week maybe we should be looking to the west, we are overdue another Lark Sparrow.

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