Merlin Welfare and Conservation: UK's Smallest Falcon

wildlife

The merlin is the UK's smallest falcon, dependent on upland heather moorland for breeding. Understanding its welfare needs supports targeted conservation on managed and unmanaged uplands.

Species Overview

The merlin (Falco columbarius) is a small, fast-flying falcon that breeds on upland moorland, particularly heather-dominated moors in Scotland, northern England, and Wales. It is migratory, with most birds moving to lowland coastal areas and farmland in winter. The UK breeding population (~1,100 pairs) has shown mixed trends: declines in some areas, increases in others. It is an Amber List species of conservation concern.

Breeding Habitat Requirements

Merlins breed on the ground in tall heather or rushes, or in crow or other raptor nests in scrubby moorland fringe. They require: open heather moorland with a mosaic of age classes for hunting; areas of longer heather or scrub for nesting; and low human disturbance during the breeding season. Their primary prey is small passerine birds (pipits, larks, finches) caught in fast low-level pursuit.

Welfare Threats

Key welfare threats include: illegal persecution (shooting and nest destruction), though reduced since the 1980s; disturbance at nest sites by walkers and recreational users; secondary poisoning from rodenticides; tick-borne louping ill (affecting both merlin and their passerine prey); loss of heather through inappropriate burning or grazing management; and climate-driven vegetation changes on upland moorland.

Relationship with Grouse Moor Management

Merlins show mixed associations with grouse moor management: predator control on grouse moors may benefit merlins by reducing nest predation; but illegal persecution (despite legal protection) on some managed moors may cause localised declines. Rotational heather burning, if managed appropriately, maintains heather mosaic beneficial to merlins; but intense burning management for grouse may reduce structural diversity.

Conservation Actions

Key conservation actions include: legal protection enforcement and investigation of illegal persecution; sensitivity in access management during breeding season; monitoring via BTO nest record scheme and BBS; working with land managers to maintain heather mosaic; and reducing tick burdens that cause louping ill in merlin populations in some areas. Ensuring prey availability (healthy populations of meadow pipits and skylarks) is also important.