Post-breeding gathering of Sandwich Terns at Baltray, July 2017.

BirdWatch Ireland are coordinating counts of terns along the Irish coast in August and September 2017. The first counts as part of this post-breeding tern survey will begin this week in Dublin Bay. The counts aim to get a better picture of tern distribution, numbers and movements after the breeding season and before migration.

Counts carried out within an hour or so of sunset are the best, to get the true number of roosting terns. Ideally you want a date where sunset (around 8pm at the moment) corresponds with a high or rising / high tide as this will make the birds easier to count (as they are gathered together and closer to shore). Additional low tide counts can be carried out to get an idea of how terns use the site.

Tide times for August at Drogheda Port, with suitable dates (for counts at Baltray and surrounding coast) highlighted in red. Source:

The more counts the better, so if you are out for a walk along the beach and encounter any terns on the beach, do a quick count and send details to BirdWatch Ireland. For more details about what to look out for and where to submit details see this website –

Although counts can be carried out at any time from mid August to the end of September, there are some key dates to keep in mind.

  • Tom Gittings is organising a coordinated count of Sandwich Tern sites in county Cork today (Wednesday 16th of August) – so anyone with Sandwich Terns in other counties, your count will get some added value on this date!
  • BirdWatch Ireland will be counting the large Sandymount / Merrion roost in Dublin Thursday and Friday (17th/18th August), and 30th/31st August and 14th/15th September – so again any counts on or beside those dates will have some added value too.

Any questions, contact Brian Burke (BirdWatch Ireland)- bburke (at)

Tide times for September at Drogheda Port, with suitable dates (for counts at Baltray and surrounding coast) highlighted in red. Source: