A pigeon’s just a pigeon, right? Not at all, says Bill Naylor – there’s a superb variety of species in this successful family, and many are stars of major collections around the world
There are almost as many species of pigeons as there are parrots. Found in all habitats, and in every part of the world except the Arctic and Antarctic, they vary in size from the ruddy ground dove (Columbina talpacoti) at 15cm (6in) long, to the Victoria crowned pigeon (Goura victoria), which is the size of a hen turkey. (The extinct flightless dodo and solitaire – both of the pigeon family – were even bigger.)
Some species have head plumes or crests, such as the Spinifex pigeon (Geophaps plumifera) and the topknot pigeon (Lopholaimus antarcticus). The cuckoo-doves (Macropygia) and quail-doves (Geotrygon) have reminded their describers of species quite different from pigeons. Some species have a body like a partridges, for example the common bronzewing (Phaps chalcoptera) and the Wonga pigeon (Leucosarcia melanoleuca) from Australia. The pheasant pigeon (Otidiphaps nobilis) from New Guinea, as well as the crowned pigeons from the same region, have evolved to resemble gamebirds.
The name “dove” is usually restricted to smaller species, but in practice “dove” and “pigeon” are interchangeable. The familiar green-winged pigeon (Chalcophaps indica) from Asia and Australasia is also called the green-winged dove, while the various species of bleeding-heart doves (Gallicolumba) are alternatively called pigeons.
The plumage of many seed-eating pigeons is often subtle in colour, but some possess striking plumage. Examples are the tambourine dove (Turtur tympanistria) from Africa and the crested quail-dove or mountain witch dove (Geotrygon versicolor) of Jamaica. The 50 species of fruit doves in the genus Ptilinopus include some of the loveliest birds in the world, notably the superb fruit dove (P. superbus). Other attractive fruit-eaters include the 38 species of imperial pigeons (Ducula) and the 28 green pigeons (Treron).
The typical pigeons are extremely fast in the air, and excellent at manoeuvring in flight. Their strong wings are used both to defend themselves and attack, but their massive “pigeon chest”, which powers the wing muscles, makes them a target for food hunters everywhere.
Pigeons were the first birds to be domesticated. The rock pigeon (Columba livia) is the ancestor of fancy, homing and feral street pigeons, and has been reared in dovecotes in Asia, Africa and Europe since medieval times. The Barbary dove and its white mutation the Java dove are ancient domestic forms of the African collared dove (Streptopelia roseogrisea).
Pigeons’ beaks are weak by comparison with those of other birds. The main exception is the tooth-billed pigeon (Didunculus strigirostris) of Samoa, with its large hooked serrated-edged bill.
Pigeons feed on seeds, berries, young leaves and invertebrates. Ground-dwelling species such as the quail-doves eat more livefood than other species. Tropical ground-dwellers such as Nicobar pigeons (Caloenas nicobarica) from Indonesia and crowned pigeons feed largely on fallen fruits.
All species have large gapes and big crops. Seeds are swallowed unhulled. Fruit pigeons swallow figs and other large fruits, excreting the stones. Most pigeons have a large gizzard, too, and swallow small stones and grit to help its work. Some fruit pigeons that feed on fruit pulp have a short intestine with abrasive walls which rub off the skins of fruits. Unlike their seed-eating relatives, their gizzards are not as important to digestion. All pigeons drink by submerging their beaks and sucking up water.
Columbids often gather in groups or flocks, but few are colony-breeders. An exception was the passenger pigeon (Ectopistes migratorious), once thought to be the most numerous bird on earth, but now extinct. Breeding as it did in massive colonies, it was susceptible to relentless hunting. After it had been reduced to small groups, its impetus to breed disappeared, and although kept in captivity in the UK and America, it became extinct in 1914.
All pigeons make a loosely woven nest of dry sticks. In captivity they readily use trays and baskets. The female normally constructs the nest from materials the male supplies. One egg (in some fruit pigeons) or more often two white eggs are incubated by both parents for 14-18 days.
Squabs (young pigeons), including those of fruit-eating species, are fed for the first 10 days on pigeon milk, produced by cells lining the crops of their parents. This makes fostering pigeon nestlings and eggs easier than with other families of birds. At Jersey Zoo, the Endangered pink pigeon (Columba meyeri) has been bred by fostering its eggs under Barbary doves. Consuming the high-protein crop milk, squabs grow quickly and may fly at two weeks of age. By contrast, the Nicobar pigeon doesn’t fledge until 12 weeks.
Pigeons have always been popular in aviculture, since most are easy to keep and breed, and are hardy and long-lived. Even the difficulty of hand-rearing, due to reproducing pigeon milk, has been overcome by the formulas devised by a number of zoos.
■ Pigeons and Doves of the World by David Gibbs and Eustace Barnes (Pica Press)
■ Pigeons and Doves of the World by Derek Goodwin (British Museum of Natural History)