A 1250+ White Wagtail roost in Holland, 1966

In early August 1966, in the holidays of my secondary school, I discovered a night roost of White Wagtail Motacilla alba in my home town Ede, in the centre of The Netherlands. I found the roost by just following the small groups of wagtails, from different angles flying towards an apparently common destination. The focal point appeared to be just inside a big factory called AKU (later AKZO). I tried to get a look inside this complex but the gatekeeper didn't let me in - school boys were just sent away in those days. All I knew now was that the wagtails had a roost somewhere at a small green spot with some bushes inside this large complex where a lot of lights were shining during the night.

However, I was more interested in knowing how many were roosting here, and I found a good spot for counting them while they came flying in. Of course I could count them only from one angle, but I checked a bit and found out that by far the most came flying in from this angle where I stood, just outside the factory wall. The areas covered by this very angle were suitable breeding areas for the wagtails - ruderal town outskirts, and further to the West the large region with small-scale farming in the Gelderse Vallei. I had actually seen them flying towards the roost from that far indeed. White Wagtail was a very common bird in that agricutural area, with lots of old-fashioned barns, freely roaming pigs, etc. in those days.... I certainly don't think the bird is as common now but I don't have numbers. The farming methods are highly intensive now.

The numbers that I counted near the roost were astonishing, as I would even say after so many years. In the new standard work (2001) Common and Scarce Birds of The Netherlands, late summer White Wagtail roosts are mentioned of size varying from tens to 800 birds. And I had at least 1250... I never published the result except in our local nature youth journal, so I will do it here now again (I kept the journal).

I counted from 6 p.m. (when there were a few birds only) until dusk set in and no more birds flew in. The numbers were:

6 August: 859
7 August: 712 (not so good weather that evening)
8 August: 987
9 August: 1252 (sunset 8.15 p.m.)
10 August: 1211
...Then I went on birding camp to the Wadden Sea I think...
2 September: 409
14 September: 231
22 September: 123
30 September: 157
7 October: 135
(20 March 1967: 95)

The birds came in groups increasing in size during the evening from 2 or 3 to 25, flying in a straight way into the roost spot (not circling around or so).

I noted the numbers per 5 minutes, and for the evening with 1252 birds the distribution is as follows:



So most of the birds came in a time span of only 30 minutes, and 40% in just 15 minutes.

Having 180+ wagtails in just 5 minutes (at 7.40 p.m.) was thrilling!

Look here for an additional graph of all 5 minutes countings from 5 - 10 August, and here the one for September (these added Nov. 2010; see here the excel-sheet with all 5-minutes countings.)

This roost can easily have had at least 1500 birds. I could not count from other angles (and friends were on holiday...) so it should be more than the 1250 I had from my spot.

This large roost is an indication of how suitable this region (Gelderse Vallei) was for White Wagtail. It still is a common bird there, but I guess not in those large numbers as formerly. Dutch politicians want less intensive farming practices now, so the region might again hold more of these lovely birds.

John van der Woude
www.jvanderw.nl - (mail: jvanderw at worldonline.nl; for ' at ' use @)
updated November 2010