Over the next few weeks, Grey Herons will be returning to begin another new breeding season. For some birders, it marks the start of the BTO Heronries Census, the longest running survey of its kind in the world. Counting nests provides by far the most efficient and accurate measure of breeding numbers for most colonial birds.
In our region, we monitor eight known heronries, with another just outside the boundary at Llwyn-on Reservoir. Currently we have volunteers visiting all apart from the large colony at Coryton on the outskirts of Cardiff. Could you help out with this site? A few visits are required to determine a count of ‘apparently occupied nests’.
It’s possible that there are a few other nesting sites around the region, as new colonies form. Grey herons nest with just one or two pairs at some sites. Are there any we have overlooked?
Please get in touch if you have any information or would like to monitor our Coryton site.