UK Wildlife

Dunnock Cryptic Ecology and Mating Systems

The dunnock is a small, unassuming bird with surprisingly complex social and mating behaviour, found throughout the UK in gardens, hedgerows, and woodland edge.

Key Facts

Dunnocks have one of the most complex mating systems of any UK bird, including polygyny and polyandry
Males engage in sperm competition, and females actively seek multiple mates
UK population around 2.3 million breeding pairs, with some recent decline
Ground foragers feeding on small invertebrates and seeds
Often overlooked despite being one of the commonest garden birds

Welfare Considerations

Dunnocks have declined in some habitats with loss of dense hedgerow and scrub. Their ground-foraging habit makes them vulnerable to cats and cold weather. Maintaining dense low cover in gardens provides vital habitat.

What You Can Do

Maintain dense hedges and shrubs at ground level for dunnock cover
Manage cats sensitively to reduce predation of ground-foraging birds
Record dunnock numbers through citizen science to track population trends