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.

Wednesday 14 March 2012

Migration slowly getting under-way.

Everything was seemingly in place for a good weekend of visible migration, the winds were light and from the south, pretty much all the way from North Africa to the Midlands, and the temperature was generally higher than the norm for this time of the year; a sure-fire recipe for summer migrants to arrive and winter visitors to leave. So, why didn’t it really happen?

My guess is that the number of migrants staging in southern Europe is still pretty low and, as a result, when the right weather conditions presented themselves only a small number of birds responded. It could be that some of our migrants are held-up much further south, in Africa. As far as the winter visitors go, the BirdTrack reporting rate is still at 50% of the mid-winter high for Redwing and Fieldfare, so some have left. The remainder have vacated gardens after the brief cold spell and are now in the wider countryside again. It is a similar picture with wildfowl; some have already left and the rest will do so over the next month or so, in a less hurried fashion.

Garganey by Dawn Balmer

So what did arrive over the weekend? Twenty-seven Garganey were counted from Dorset to Norfolk. Being one of our earlier summer visitors, these were bang on cue. The same couldn’t be said of the Lesser Whitethroat seen in Essex though; the average arrival date for this species is 23 April. Of course, this bird could well have spent the winter much closer to Essex than sub-Saharan Africa. This might also be the case with the Whitethroat, also heard singing in Essex, as the average arrival date for this species is 15 April.

A very small number of Sand Martins and Wheatears trickled through, reaching as far north as Lancashire, and the first Willow Warbler was heard in Devon, twenty days ahead of its average arrival date of 31 March.

The first overshooting southern European migrant, in the shape of a Short-toed Treecreeper, put in a brief appearance in Kent over the weekend but disappeared almost as soon as it was found, whilst there are (as yet unconfirmed) reports of a female Rock Thrush in Cornwall.

Although the high pressure that has dominated during the last week will move off to the east over the next few days, the conditions are still favourable for migrants to arrive from the south.This weekend could be a good one to be out and about, with Saturday looking a slightly better bet than Sunday.

Stop press! The first Little Ringed Plovers have been seen in Dorset and Lancashire.

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