©
© Marcel Burkhardt
Conservation programme for birds in Switzerland - Priority species
Common Tern
The Common Tern breeds on pioneer areas by bodies of water that are protected from predators such as foxes. Its original breeding sites on gravel banks along the rivers in the Central Plateau have been lost due to the straightening of watercourses. To replace these, a network of nesting platforms and rafts has been created on many large lakes and some small ones, which the species has accepted well. Around 700 pairs in 20 colonies are currently breeding in Switzerland. They are concentrated in the Lake Geneva region, the Three Lakes region and the Zurich region. Maintaining this network of nesting aids is very important for keeping the species here as a breeding bird. Structural work is carried out on the platforms to reduce competition with the Yellow-legged Gull for nesting sites.
Distribution and development
Schematic distribution
Schematic distribution during the breeding season (ochre), in winter time (dotted in blue) or during migration periods (dotted in vinaceous).
Breeding bird index
The graph shows the relative evolution of the breeding population in Switzerland (100 = mean value). Example: A value of 130 means that the population in the corresponding year was 30% above the mean value of the entire period considered.
Habitat and food
©
© Claudia Müller
The nesting rafts in Fanel (BE), photographed on 14 September 2024, are currently home to one of the largest Common Tern colonies in Switzerland.
©
© Benno Ott
Pair feeding two chicks with small fish on the nesting platform in Horgen (ZH), June 2025.
Conservation programme for birds in Switzerland - Priority species
Common Tern
The Common Tern breeds on pioneer areas by bodies of water that are protected from predators such as foxes. Its original breeding sites on gravel banks along the rivers in the Central Plateau have been lost due to the straightening of watercourses. To replace these, a network of nesting platforms and rafts has been created on many large lakes and some small ones, which the species has accepted well. Around 700 pairs in 20 colonies are currently breeding in Switzerland. They are concentrated in the Lake Geneva region, the Three Lakes region and the Zurich region. Maintaining this network of nesting aids is very important for keeping the species here as a breeding bird. Structural work is carried out on the platforms to reduce competition with the Yellow-legged Gull for nesting sites.
Birds of Switzerland
Common Tern
To the species profile in the bird database
Project managers
Threats, activities and forecasts
Limiting factors and threats
The availability of nesting sites is a limiting factor. Since the straightening of rivers has resulted in the disappearance of natural breeding sites on gravel banks in rivers and deltas, the species now nests almost exclusively on artificial nesting aids.
Breeding season
- An adequate network of maintained nesting platforms and rafts is important, to provide sufficient space for nesting and allow the birds to evade predation pressure.
- Competition with the Yellow-legged Gull for nesting sites should be reduced by carrying out structural work.
Migration/ Winter
- Sufficient resting habitats are available.
- Overwinters in Africa.
Necessary activities
Monitoring
- The breeding population is surveyed annually by local volunteers. This means that problems can be detected and addressed at an early stage.
- The Swiss Ornithological Institute records the populations in each area.
Conservation
- Local organisations have established a network of nesting aids on suitable bodies of water, which they maintain.
- The Swiss Ornithological Institute and BirdLife Switzerland organise regular meetings to enable colony guardians to exchange ideas.
Research
- Knowledge of factors influencing the take-up of new nesting sites (especially flat roofs).
Prospects for success and prognostics
- Provided the network of nesting aids is maintained, the species may survive here.
- Competition with Yellow-legged Gulls is reduced by work carried out on the nesting aids (e.g. covering them or taking them out of the water until shortly before the arrival of the Common Tern, adding further rafts/platforms if space is short).
- Expanding the network of nesting aids gives the birds a better chance of evading predation pressure.
- Return of the Eurasian Eagle-Owl causing some nesting sites to be abandoned.
Conservation measures and stakeholders
Provide breeding platforms
Breeding platforms and rafts on watercourses provide alternative habitats to undisturbed gravel banks.
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Cantons
Municipalities
Nature conservation
Prevent / minimize disturbances
Disturbances by humans, dogs or vehicles can, amongst other things, affect habitats and lead to breeding losses.
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Cantons
Hunting and fishing
Municipalities
Nature conservation
Tourism and sport
Publications
©
© Marcel Burkhardt
Birds of Switzerland
Common Tern
Common Terns are vociferous, elegant and graceful birds with a very smooth and sweeping flight. They swoop into the water with impressive, vertical dives to catch small fish. In our country, the Common Tern used to breed on gravel islands in natural rivers. These breeding sites, however, have been lost due to the channelling of rivers. Thanks to newly erected rafts, platforms and art...
To the species profile in the bird database
