Seabirds

Common Tern Welfare and Colony Disturbance Management

Common terns nest in dense colonies on coastal shingle beaches and islands. Human disturbance causes repeated flushing that exposes eggs and chicks to predation and sun exposure. Careful visitor management is essential for colony welfare.

Key Facts

Common terns nest in dense colonies of up to several thousand pairs
They nest on bare shingle or short grass, making nests extremely vulnerable to disturbance
Flushing from nests exposes pale, speckled eggs to gull and corvid predation within minutes
Chicks that scatter from disturbed colonies are difficult for parents to locate and may die of cold
UK populations declined by 50% between 1969 and 2007, partly linked to disturbance

Welfare Considerations

Colony disturbance by dogs, humans, or aerial predators causes simultaneous flushing of hundreds of pairs, leaving all eggs and small chicks exposed simultaneously. Large-scale gull predation events following disturbance can eliminate the breeding output of an entire colony in minutes. Adults that repeatedly flush from nests experience chronic stress hormones that impair immune function and parental care quality over the breeding season.

What You Can Do

Never enter marked tern colony areas during April to August
Keep dogs on leads on beaches near tern breeding colonies
Report disturbance of tern colonies to RSPB Investigations
Support RSPCA Assured and RSPB reserve management protecting tern colonies
Donate to Tern monitoring programs at RSPB reserves and Seabird Group surveys