Merlin are iconic falcons of moorlands and are the UK’s smallest bird of prey, with males being only slightly larger than blackbirds. They mainly hunt small birds such as meadow pipits and skylarks, sometimes hunting other species such as starlings, small waders, and insects such as fox and emperor moths.
The UK is at the south-west extremity of the merlin's European range and the population here is thinly scattered across upland moorland from south-west England to Shetland. In winter, there is also an influx of merlin that breed in Iceland, which migrate to the UK to spend the winter in a warmer climate where small birds are likely to be more plentiful.
Merlin typically nest on the ground amongst tall heather, but in several regions will also nest in trees using old crow nests. They lay 3-5 eggs and chicks normally fledge within 25-32 days, being fully independent about a month after that. In 2017, the British Trust for Ornithology estimated that for every breeding attempt an average of 1.5-2 merlin chicks fledged, suggesting that chick survival may be low and could be limiting population recovery.