Wildlife

Common Tern Colony Welfare: Nesting and Disturbance Management

Common terns (Sterna hirundo) nest in dense colonies on coastal and inland sites, making colony management critical for the welfare of thousands of birds simultaneously.

Key Facts

UK common tern population is approximately 12,000 breeding pairs, with colonies ranging from a few pairs to thousands
They are highly aggressive defenders of nesting territory, causing welfare stress during neighbour disputes
Chicks are nidifugous but stay near the nest — colony disturbance causes chick dispersal and hypothermia
Cold, wet weather during chick rearing is the leading cause of breeding failure in poor summers

Welfare Considerations

Colony disturbance is the primary human-caused welfare threat — a single disturbance event can cause all chicks to scatter into cold water or vegetation, causing mass hypothermia mortality. Predator pressure from mink, foxes, and gulls causes chronic stress evidenced by extended alert postures and reduced feeding rates. Welfare-positive colony management includes predator exclusion fencing, roped-off exclusion zones, and warden presence during the breeding season.

What You Can Do

Observe strict no-approach distances at designated tern colony sites during breeding (May-August)
Support the RSPB and Wildlife Trusts in managing tern colony sites with predator exclusion fencing
Keep dogs on leads near coastal breeding sites during the tern breeding season
Report disturbance or predator activity at tern colonies to the relevant conservation organisation