Glamorgan Bird Club Rookery Survey 2022/23

We’re excited to announce that Glamorgan Bird Club will be throwing its support behind a local, and a Wales-wide Breeding Rook Survey, over the next couple of years.

Two Rook surveys are being held alongside each other during spring 2022 and spring 2023 with the aim of gaining a better understanding of the population and distribution of this familiar, yet declining member of the crow family breeding here in Eastern Glamorgan and across Wales.
The Wales-wide survey is being led by the Welsh Ornithological Society (WOS) and Glamorgan Bird Club will lead on gathering additional records of rookeries in our region.

Why Rooks? Why now?

Rooks are in trouble and need help. They have been moved from Green to Amber in the recently published Birds of Conservation Concern 5. In Wales, they appear to be in more trouble than elsewhere. The BTO’s Breeding Bird Survey (BBS) index for Wales fell by 58% during 1995-2018, accelerating after 2010, and the rate of decline is considerably greater here than in any other UK nation. In Eastern Glamorgan, Rooks were confirmed as breeding in only 13% of tetrads (2km x 2km squares on an OS map) in the BTO 2007-11 Atlas, compared to 21% in the 1988-91 Atlas.

Two surveys working side by side

WOS’ survey aims to help establish why the decline has been so rapid in Wales and to create a robust breeding population estimate. This survey is based on volunteers visiting a number of specially chosen tetrads (2km x 2km squares on an OS map) based on those surveyed during previous Rook surveys. A number of those tetrads have been allocated to us here in Eastern Glamorgan.

GBC’s survey will complement and add value to the WOS survey. It asks volunteers to visit all those tetrads which had confirmed, probable and possible breeding records of Rooks in Eastern Glamorgan during the 2007-11 BTO National Atlas period as well as tetrads with active rookeries identified more recently. The aim of this survey is to map out in greater detail the size and distribution of active rookeries in our region.

Can you help us find and record our local rookeries?

Do you know where rooks nest in your area? We’d love to hear from you, even if you’re not able to take part in the survey itself.
Also, if you’ve never taken part in a bird survey before, the GBC and WOS surveys are an excellent way to start. Both surveys use the same methodology:

  • You must be able to confidently identify Rooks.
  • Make one visit to your allocated tetrad(s) sometime between 1 March and 15 April in either 2022 or 2023
  • Count the number of active nests in any rookeries you find on your visit
  • Note the tree species used for the active nests (we’ll provide you with a tree ID guide)
  • Or, if there are no rookeries in your tetrad, record a ‘0’ and become a ‘Zero Hero’. Negative data are equally as important as counts in this survey – particularly if you know where there was once an active rookery which has now fallen silent.

For more information and to book your tetrad(s)

Please see the map below which displays the allotted and vacant tetrads. Beware that the map expands and contracts if you scroll whilst your cursor is on it, and it can be dragged and repositioned. The small black & white square with an arrow in the header, left of the small Rook image, activates a pop-out menu which shows the colour key. The menu will also pop-out when you click on one of the tetrads. The pop-out shows the tetrad’s OS grid reference and has a link to maps of the tetrad. On these maps the tetrad is the larger square bordered in pink.

To report a rookery in your area, or to book your tetrad(s) or find out more about these surveys and vacant tetrads in Eastern Glamorgan, please contact local organisers, Ceri Jones and Dan Jenkins-Jones via