on to Mali or Chad. Young birds from the European populations stay on in Africa after their first winter and return to Europe at the age of two years. Asian black-tailed godwits winter in Australia, Taiwan, the Philippines, Indonesia, and Papua New Guinea. Black-tailed godwits are much more likely to be found on inland wetlands than the more coastal bar-tailed godwit. They migrate in flocks to western Europe, Africa, south Asia and Australia. Although this species occurs in Ireland and Great Britain all year-round, they are not the same birds. The breeding birds depart in autumn, but are replaced in winter by the larger Icelandic race. These birds occasionally appear in the Aleutian Islands and, rarely, on the Atlantic coast of North America. Behaviour Breeding Black-tailed godwits are mostly monogamous; although it was not recorded in a four-year study of 50–60 pairs, bigamy was considered "probably frequent". A study of the Icelandic population showed that despite spending winter apart, pairs are reunited on their breeding grounds within an average of three days of each other. If one partner does not arrive on time, 'divorce' occurs. They nest in loose colonies. Unpaired males defend a temporary territory and perform display flights to attract a mate. Several nest scrapes are made away from the courtship territory, and are defended from other godwits. Once eggs are laid, an area of around the nest is defended. The nest is a shallow scrape on the ground, usually in short vegetation. The eggs may be hidden with vegetation by the incubating parent. The single brood of three to six eggs, coloured olive-green to dark brown, measure and weigh each (of which 6% is shell). Incubation lasts 22–24 days and is performed by both parents. The young are downy and precocial and are brooded while they are small and at night during colder weather. After hatching, they are led away from the nest and may move to habitats such as sewage farms, lake edges, marshes and mudflats. The chicks fledge after 25–30 days. Black-tailed godwit productivity varies, positively, with spring temperatures. However, during extreme events, such as a volcanic eruption, complete breeding failures can occur. Food and feeding They mainly eat invertebrates, but also aquatic plants in winter and on migration. In the breeding season, prey includes beetles, flies, grasshoppers, dragonflies, mayflies, caterpillars, annelid worms and molluscs. Occasionally, fish eggs, frogspawn and tadpoles are eaten. In water,