Outside the breeding season, small groups of goldcrests maintain exclusive winter feeding territories, which they defend against neighbouring groups. As they roam around their territory, they frequently join loose flocks of other wanderers such as tits and warblers. This kinglet, like other species that prefer mixed-species foraging flocks in winter, hunts over a greater range of heights and vegetation types than when feeding alone. For species that tend to feed in flocks, foraging success while in a flock was about twice that for solitary birds. A consequence of feeding in a flock is that foraging sites may be restricted to avoid competition with other species. In a Swedish study, coal tits and goldcrests foraged in the outer foliage, while the larger willow and European crested tits used the inner canopy. In sites where the numbers of willow and crested tits was artificially reduced, goldcrests and coal tits extended their foraging to include the inner canopy, but did not do so where the larger tits were retained. In some areas, wintering birds have developed the habit of coming to feeding stations and bird tables to take fat, sometimes with warblers such as the common chiffchaff and blackcap.