This small owl is a relatively recent addition to our avifauna, most commonly encountered in the mixed farming landscapes of southern and south-eastern England. Less strongly nocturnal in its habits than many of our other owls, the Little Owl may be seen during daylight hours, perhaps perched in a tree or on a fence post, from which it can scan the ground for small mammals and invertebrates.
A welcome arrival
The Little Owl is a non-native, first introduced in the late 1800s by rich landowners who thought that the species would be a useful addition to our native avifauna. Many of the early attempts to introduce Little Owls into Britain failed, the owls dying soon after release, but a series of releases that took place at Stonewall Park, near Edenbridge in Kent, saw the Little Owl become established, with the first successful breeding recorded in 1879. The population began to grow and soon saw birds become established in neighbouring counties. Further releases elsewhere in Britain also had a part to play, particularly those that took place in Northamptonshire in the late 1880s, and by 1909 the Little Owl was breeding as far north as Derbyshire, reaching Wales in 1916 and Scotland in 1958. Today the Little Owl is largely restricted to England, with the greatest numbers to be found in the south-east of the country.
A ‘hole’ lot of opportunities
The Little Owl is a cavity-nesting species, its small size enabling it to make use of a wide range of opportunities. Pairs will occupy tree cavities, cavities within stone walls and buildings, and even rabbit burrows. Favoured tree species include Oak and Ash, though they will also use old fruit trees in orchards, the nest cavity typically between two and four metres off the ground. They also use nest boxes, though they seem less willing to take to these than barn owls or tawny owls do. There seems to be a preference for a dark nesting chamber, so Little Owl nest box designs tend to feature a long tunnel for an entrance and have internal baffles to reduce the amount of light getting in. Birds will occupy favoured sites throughout the year, advertising ownership from February and with courtship typically peaking during March and April.
While some introduced species have gone on to become a conservation problem, the Little Owl has generally fitted in without impacting on other species, apparently occupying a vacant niche. Some concerns were raised by game-rearing interests, who felt that the Little Owl might be taken young pheasants and partridges. This prompted an investigation by Alice Hibbert-Ware of the BTO, whose Little Owl Food Enquiry report, revealed that Little Owls favoured mice, voles and large invertebrates and only rarely took young gamebirds. The species did become a conservation problem on a couple of offshore islands, where the owls predated Storm-Petrels and Manx Shearwaters at their breeding colonies, prompting their removal.
The need for knowledge
Project Barn Owl, a joint BTO/Hawk & Owl Trust study, collected additional information on breeding Little Owls during the mid-1990s, something that enabled BTO researchers to produce the first robust and repeatable population estimate for the Little Owl. This revealed a population of between 4,000 and 8,500 breeding pairs. There is evidence to suggest that the population may have since declined and a new national survey is needed, something that the BTO plans to address over the next few years. Work on refining survey methods is already underway, with researchers examining the use of tape-playback as a tool for securing a reliable count of the number of breeding pairs within an area. The future of the Little Owl within Britain looks secure. However, as predator of small mammals and larger invertebrates, the fortunes of this species may act as a barometer to the changing fortunes of the species on which it preys.
A wider context
Evidence of a long-term decline can be seen in Little Owl populations elsewhere within Europe, with habitat loss and changes in agricultural practices thought to be responsible. Studies suggest that the survival of young birds entering the population may be a particularly strong driver for population change, and more work is urgently needed to halt the decline.