Pied Wagtail roosting flock is still at Heathrow T5

This post is simply to document the calendar of the Pied Wagtails that roost at London Heathrow’s Terminal 5 during the cold months. Today was Thursday 13^th March 2014 and is the latest that I have seen the birds here. Their numbers have dropped since January when as many as 1400 were seen. Approximately 500 were seen here this evening.

This year’s numbers are down on last year, but this may be down to a significant prune of the “bird-proof trees” last autumn which reduced the outer branch capacity. In previous years the roosting flock has exceeded 3000 during extreme cold nights.

The wagtails find warmth and shelter from the elements as they are sheltered between the terminal and the multi-storey car park. Recent rises in temperature may have contributed to the drop in numbers as the birds roost elsewhere in smaller flocks.

See the previous posts on the Wagtails of London Heathrow Airport at the links below;

http://redgannet.blogspot.co.uk/2012/01/where-did-all-these-wagtails-come-from.html

http://redgannet.blogspot.co.uk/2013/01/the-wagtails-are-back.html

http://www.redgannet.blogspot.co.uk/2013/12/i-have-been-watching-out-for.html

Harmondsworth Moor is also very close to Heathrow Airport and a post can be seen at this link.
Birding, Bird watching, London UK, Heathrow Airport, T5

I have been watching out for the Pied Wagtails as the weather gets colder. They have been roosting, at least for the last couple of years, in the trees at London Heathrow’s Terminal 5.

This year the maintenance contractors at the airport gave the trees a severe pruning and I wondered if the wagtails would still find it an attractive place to roost. They had shown a marked preference for the thinnest of branches, but the trees had been reduced to stumps by enthusiastic loppers.

A few whippy branches remain on the trees and the birds have returned. I first noticed them on December 12^th. I had associated the arrival of the birds with temperatures well below zero, but this year they have appeared before the extreme cold snap.

There are enough whippy branches left on the trees to give roosting room for a flock of 1000 plus wagtails, but I wonder if that is as many as we have seen in the previous years. Perhaps it will build as the weather gets colder and the flock will spill over into the next stand of trees if the roosting room runs out.

Someone suggested that the contractors had done a shoddy job, but I prefer to think that the few, thin roosting branches were left by a considerate tree surgeon with the wagtails in mind.

If you wish to see the local form of the White Wagtail, they roost outside London Heathrow’s Terminal 5 at the southern end of the building in the sheltered trees at Google Earth ref; 51 28 14.52N 0 29 21.66. They come in from the surrounding area around dusk and stay until the early light. The terminal buildings give them protection on all sides and must be a relief from the cold on the bitterest of nights.

Previous posts about the Wagtails of Terminal 5 can be seen at the links below;
http://www.redgannet.blogspot.co.uk/2013/01/the-wagtails-are-back.html
http://redgannet.blogspot.co.uk/2012/01/where-did-all-these-wagtails-come-from.html