Countryside Bird Survey

Monitoring Ireland's breeding countryside birds

Each summer over 200 skilled volunteers, NPWS Rangers and BirdWatch Ireland staff survey breeding birds across the Irish countryside. The Countryside Bird Survey (CBS) is coordinated by BirdWatch Ireland and funded by the National Parks and Wildlife Service.

What’s involved?

During the breeding season, CBS counters record all birds seen and heard during two early morning walks in pre-assigned 1km grid squares. Two visits are made to the site – one in early summer (April to mid-May) and the second about 4 weeks later (mid-May to end June). As many birds are detected first by sound (and often not seen) it is helpful to be able to identify birds by song and call as well as sight. Survey squares occur in a broad range of habitats across every county, from upland blanket bog to lowland farmland and woodland.

Why do we count breeding countryside birds?

CBS has served to show that populations of our common and widespread birds are continually changing. While most species are quite stable, some such as Goldfinch and Blackcap have increased substantially over the last 20 years. Some species such as Stonechat and Grey Wagtail have been shown to be prone to big fluctuations, especially after severe winters, while others including Kestrel, Skylark and Stock Dove are showing worrying declines. Such declines can be noted anecdotally, however this survey aims to detect and quantify such changes using robust, scientific but user-friendly methods. Over time, reasons for decline may be identified and there will be opportunities to provide advice to help reverse such trends.


Enter your CBS records


Map of CBS coverage


Get involved in CBS

Species Trends

Population trends of countryside birds monitored through CBS.

Countryside Bird Population Indicators

Common Bird Index (CBI) and Common Farmland Bird Index (CFBI).

Square Summaries

Summary count data for grid squares monitored through CBS.

Scientific Research

Reports and studies at national and international level, incorporating CBS data.


Bird Songs & Calls

Being able to identify birds by their songs and calls is vital for taking part in CBS. See here to help you get to grips with the sounds of some of our most common bird species. This is also a good refresher in advance of the next CBS season.

CBS and Countryside Bird News

CBSHedgerowsMigrationNewsSurveys and Monitoring
May 26, 2020

Milestone Publication on the Status of Ireland’s Countryside Birds

Last week hundreds of surveyors for the Countryside Bird Survey (CBS) received their printed copy of the CBS ‘Irish Wildlife Manual’ in the post – a reward for the huge…
Wheatear-on-a-rock CBSMigrationSurveys
March 29, 2019

Early migrants add spice to first CBS visits

Dick Coombes, coordinator of the Countryside Bird Survey (CBS), describes the sites and sounds of the Irish countryside in spring: "One of the joys of carrying out your first CBS…

Latest CBS Publications

CBS News 2020

The 2020 issue of the newsletter of the Countryside Bird Survey, published in March 2020.

Countryside Bird Survey Report 1998-2016

Report on the results of the Countryside Bird Survey (CBS) from 1998 to 2016.

CBS Counter Manual

Counter manual detailing the methodology for taking part in the Countryside Bird Survey (CBS).

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