shape of the bills is linked to the diet of the different species. The large bills of the Ciconia storks are the least specialised. Larger are the massive and slightly upturned bills of the Ephippiorhynchus and the jabiru. These have evolved to hunt for fish in shallow water. Larger still are the massive daggers of the two adjutants and marabou (Leptoptilos), which are used to feed on carrion and in defence against other scavengers, as well as for taking other prey. The long, ibis-like downcurved bills of the Mycteria storks have sensitive tips that allow them to detect prey by touch (tactilocation) where cloudy conditions would not allow them to see it. The most specialised bills of any storks are those of the two openbills (Anastomus.), which as their name suggested is open in the middle when their bill is closed. These bills have evolved to help openbills feed on their only prey item, aquatic snails. Although it is sometimes reported that storks lack syrinxes and are mute, they do have syrinxes, and are capable of making some sounds, although they do not do so often. The syrinxes of storks are "variably degenerate" however, and the syringeal membranes of some species are found between tracheal rings or cartilage, an unusual arrangement shared with the ovenbirds. Distribution and habitat Storks have a nearly cosmopolitan distribution, being absent from the poles, most of North America and large parts of Australia. The centres of stork diversity are in tropical Asia and sub-Saharan Africa, with eight and six breeding species respectively. Just three species are present in the New World: wood stork, maguari stork and jabiru, which is the tallest flying bird of the Americas. Two species, white and black stork, reach Europe and western temperate Asia, while one species, Oriental stork, reaches temperate areas of eastern Asia, and one species, black-necked stork, is found in Australasia. Storks are more diverse and common in the tropics, and the species that live in temperate climates for the most part migrate to avoid the worst of winter. They are fairly diverse in their habitat requirements. Some species, particularly the Mycteria "wood storks" and Anastomus openbills, are highly dependent on water and aquatic prey, but many other species are far less dependent on this habitat type, although they will frequently make use of it. Species like the marabou and Abdim's stork will frequently be found foraging in