Wednesday, 16 May 2018

A new BBS square

I have been counting birds on a 1km square for the BTO Breeding Birds Survey (BBS) since 2006 and for this year I have taken on a second square.  My first square is 1km of unimproved grassland and bog with no trees or shrubs and the commonest birds are meadow pipit, skylark and curlew.  The new one couldn't be more different as it is all forest.

The two 1km transects are broken down into 200m sections and birds are counted in zones <25m, 25-100m, and >100m on two visits, one in May and one in June.

Although the transects mainly run along the tracks through the forest, with many tall trees on either side, there are areas where timber has been harvested or there is new plantation so there are some long distance views as well.

In other places the view is very limited and birds are mostly identified by their calls or song.

My first square has yielded a total of 29 species over 12 years, with an average of 11 per year (and probably about 9 per visit).  My new square has been surveyed three times in the past 12 years with a total 44 species -  21 per year (including 0 skylarks and 0 curlews).

The commonest birds in the new square on yesterday's visit were chaffinch, woodpigeon and mistle thrush.  Other highlights were cuckoo (several), jay, siskin, crossbill, redpoll, red grouse, willow warbler and chiffchaff.

Here is a very distant shot of a redpoll, a bird I usually see only in the winter.

And a siskin.

At the end of the first transect a more familiar bird was waiting.

The BBS also records mammals.  Near the end of the first transect this young roe buck popped out in front of me.

Because I was downwind and standing still he couldn't quite make me out and advanced down the track several times, sniffing the air.  It is a very remote spot so perhaps he had never seen a person before.  Eventually he lost interest and wandered off.

I'll be back for a second visit next month.  The latest BBS annual report - for 2017 - has just been published.  It, and all previous reports, can be accessed here.


  1. That's a great post Chris, really interesting to see the new square. Very different! Very nice selection of birds. What are the cuckoos parasitising there? Were they generally "heards" that may have been after local meadow pipits?

    1. I expect the cuckoos were after meadow pipits Phil as there were quite few around. The cuckoos were difficult to count as they move around a lot. I could hear three different birds when I started although two were behind me so didn't count. I also watched one fly half a kilometre while calling.