The Problem of Birds Escaping from Captivity
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THE PROBLEM OF BIRDS ESCAPING FROM CAPTIVITY By DEREK GOODWIN THE acceptance or rejection of rarities and new candidates for the British list is often made difficult by the possibility of their being escapes from captivity. In many cases a certain decision is impossible and the only practical course is to take into considera tion all the evidence and decide for the likeliest hypothesis. This article is written principally in the hope of giving assistance in this respect. Secondarily, it will, I hope, stimulate bird-watchers to identify and observe even those species which are obvious escapes. The behaviour and adaptability, or lack of it, of birds which thus find themselves far from their normal range and often far from any suitable environment, is of the utmost interest. continued... 339 340 BRITISH BIRDS [VOL. XUX It would take too long to discuss all the species which have been imported and sold in this country during the past ten years. It must be remembered, therefore, that the birds dealt with in this paper are in the main only those which have been, and in many cases still are being, imported into this country in some quantities. Also, the numbers of the different species imported may fluctuate widely in response to trade, politics and other factors. Probably by the time this appears in print some species not even mentioned herein will be on sale in thousands and some now to be found in every bird-dealer's will no longer be obtainable. In assessing which birds have been most commonly imported since the war I have relied very largely on dealers' advertisements appearing in Cage Birds and other journals. One possible source of error here is that birds readily sold may be advertised only once whereas a like number of some less popular or more expensive species might be "on sale" for a considerable period. As an example of this the "pet department" of a certain London store had the same pair of Bronzewing Pigeons (Phaps calcoptera) "on sale" for about four years in the 1930s. In most cases, however, I think I have made a fairly accurate guess at the state of affairs. No attempt has been made to gather statistics of the numbers involved. In the more abundantly imported species—such as many of the small African or Asian seed-eating Passerines—it must run into very many hundreds, and more probably thousands, of each species in the course of a year. COUNTRIES OF ORIGIN The Budgerigar (Melopsittacus undulatus), Bengalese Finch (Munia striata, domestic form), Zebra Finch (Poephila guttata) and Diamond Dove (Geopelia cuneata) are now domesticated and the majority sold are bred in this country. In some other species, especially in some of the parrots, breeding accounts for a large proportion of the specimens extant in this country. Most foreign birds offered for sale are, however, wild-caught specimens. The main exporting countries—or at least the regions whence the birds originate—are India, West Africa, South America (probably Brazil), Central America (? Mexico) and' the Indo-Malayan region. Australia and southern Africa (? Portuguese East Africa) con tribute to a somewhat less extent. (Many of the Australian seed- eaters are fairly easy to breed in warm climates, where termites can be obtained ad. lib, and many of those appearing on the markets are, I understand, captive-bred specimens from South Africa.) GROUPS AND SPECIES IMPORTED Weaver-finches (Ploceidae). Weavers, whydahs, waxbills, munias and grassfinches of various species are imported in considerable numbers. None of them is at VOL. XLIX] THE PROBLEM OF ESCAPES 341 all likely to reach Britain unaided. In many, either both sexes or the males in breeding plumage are strikingly coloured. None closely resemble any European species. Nevertheless, I know of a case where three bird-watchers—field-guide in hand—mis- identified escaped Avadavats (Amandava aman&ama) as Scarlet Grosbeaks (Carpodacus erythrinus)! The true sparrows are seldom imported with the exception of the Golden Sparrow (Passer luteus) which has been widely offered for sale. In its yellow, brown, and chestnut plumage it might at first glance be mistaken for one of the vagrant buntings. Finches and buntings (FringiUidae and Emberizidae). Now that it is illegal to sell British birds, other than close- ringed, captive-bred specimens, the European races of the Bull finch (Pyrrhula pyrrhula) are no longer imported and sold in numbers, as was formerly the case. Many foreign finches are, however, commonly on sale, although their numbers, in species and individuals, are less than those of the weaver-finches. Some are quite distinctive, but others of this group are the most apt of any to cause confusion. Some of the African canaries (Serinus spp.), including the abundantly imported Green Singing Finch (S. mozambicus) are very like the Serin (S. canarius serinus) in general appearance and mannerisms. Hence it is important to notice the markings of any strange greenish or yellowish finch in some detail before coming to conclusions as to its identity (see discussion on page 344-345). The Common Rosefinch or Scarlet Grosbeak (Carpodacus erythrinus) has been imported, and presumably sold, in large numbers. Some of its occurrences in Britain of recent years should, therefore, be viewed with suspicion. Of the true buntings (Emberiza and allied genera) only the Red-headed Bunting (E. bruniceps) has been, and is, imported and sold in any appreciable numbers. The bird is usually sold under the dealers' name of "Indian Yellow Bunting" or simply as "Yellow Bunting". The price asked is less than that for most foreign birds and much lower than that of any British finches with comparably bright plumage. This fact and the large numbers involved make it almost certain that birds of this species will in many cases have been bought by people with no real or lasting interest in bird-keeping. Such people are particularly likely to let their birds escape through carelessness or to tire of and liberate them. Judging by the number of recorded occurrences of this species in recent years some such factor seems likely to have been at work. Some of the American "buntings" (Passerina spp.) are imported and sold, seldom in very large numbers. These brilliant finches are hardly to be confused with any species that might get here by its own efforts. The breeding of finch hybrids, between different species of European finches or, more commonly between one of these and a 342 BRITISH BIRDS [VOL. XLIX domestic Canary (S. c. canarius), is popular with many bird- keepers. Such hybrids usually show their parentage fairly obviously (those with the Canary usually inherit indications of the streaked mantle and yellowish rump and belly of a wild Canary, rather than a clear yellow colour) but are often puzzling to the uninitiated. As they are often extremely hardy, with the wild parent's initiative but the canary's tarneness in the matter of coming to widows or bird-tables for food, they sometimes survive considerable periods at liberty. I was recently shown a photograph of a bird which was associating with wild Greenfinches (Chloris chloris) and had puzzled several bird-watchers. It was a Goldfinch-Canary hybrid. Timaliidae. Several species of this group are imported. Since most of them come from the Himalayan regions and are non-migratory, or nearly so, they are never likely to occur here except as escapes. Most commonly imported is the Pekin Robin (Leiothrix lutea) of which dealers have had large numbers in recent years. In the past many attempts have been made to introduce this most attractive species, but without permanent success. Escaped or liberated birds have often survived for long periods and even reared young. Blue-winged Sivas (Siva cyanea) and Silver-eared Mesias (Mesia argentigula) have been imported in much smaller numbers. Several of the Laughing-thrushes (Garrulax spp.) have been on sale. The dealer's name "Jay-thrushes" gives a good impression of what Laughing-thrushes look like in shape and stance, though they are weaker-winged and keep more to cover than either thrushes or jays. With the exception of the Pekin Robin, none of these birds seems to be imported in any quantity. Starlings (Sturnidae). The Hill Mynah (Eulabes religiosa) is commonly imported. These big black arboreal starlings, with their orange legs and bills and yellow head skin, are quite unmistakeable. Vast numbers of young are taken from the nest and hand-reared, there being a considerable trade in them not only to Britain and Europe but to America and the Far East as well. Their tarneness and powers of mimicry are well-known, but the "wolf-whistle" appears to be an innate note. A few Bank Mynahs (Acridotheres gingianus) have been imported since the war, as must at least one House Mynah (A, tristis) an escaped specimen of which lived for about four years in central London. The Rosy Starling (Pastor roseas) has been often on sale. Some of the African glossy starlings (Lamprocolius and Spreo spp.) are quite commonly imported and as they often breed well in captivity, English-bred specimens are sometimes on sale. Thrashes and chats (Turdidae). Of the more typical thrushes the only species frequently imported VOL. XLIX] THE PROBLEM OF ESCAPES 343 and sold is the Orange-headed Ground Thrush (Geokichla citrina). More than one of these handsome slate-grey and rufous-orange thrushes have escaped and been at large for some time in recent years. American Robins (Turdus migratorius), some of the rock thrushes (Monticola spp.) and Blue Whistling-thrushes /(Myiophoneus caeruleus) are sometimes on sale, but in small numbers. Of the smaller birds of this family the Shamah (Kittacincla macroura) and the Magpie-robin (Copsychus saularis) are the only ones commonly on sale.