Genetic Diversity, Phylogenetic Relationships and Conservation of Edwards's Pheasant Lophura Edwardsi
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Bird Conservation International (1999) 9:395-410. © BirdLife International 1999 Genetic diversity, phylogenetic relationships and conservation of Edwards's Pheasant Lophura edwardsi ALAIN HENNACHE, ETTORE RANDI and VITTORIO LUCCHINI Summary An historical study shows that the present day ex situ population of Edwards's Pheasant Lophura edwardsi, now numbering over 1,000 living specimens, origin- ated in the 1920s from at least six different sources and c. 30 potential founders, including more males than females. Partial sequences, 820 nucleotides long, of the mitochondrial DNA (mtDNA) control-region were obtained in representat- ives of about half of 21 captive-reared bloodlines, identified from data in the revised International Studbook. All captive-reared birds had identical sequences. Sequences of mtDNA obtained from museum skins and samples of birds col- lected in the wild were slightly different from that representing the captive- reared birds. The lack of mtDNA variability in the captive stock is probably due to the small number of founding females and genetic drift during c. 30 genera- tions of captive breeding. Estimation of true extent of mtDNA sequence variabil- ity in historical and living wild Edwards's Pheasants awaits the procurement and analysis of more specimens. At least one bloodline of captive Edwards's Pheasant is polluted with exogenous genes resulting from past hybridization with Swinhoe's Pheasant L. sivinhoii. Edwards's Pheasant is more closely related to Vietnamese Pheasant L. hatinhensis and Imperial Pheasant L. imperialis than to several other taxa regarded as full species in the genus Lophura. However it is not yet possible to determine the extent of their evolutionary divergence and of their proper taxonomic rank. The initial results of this genetic research suggest that there should be efforts to (1) expand field sampling and genetic analyses of wild populations of Lophura species, (2) purge the captive stock of Edwards' Pheasant of all hybrids, (3) apply microsatellite analyses to estimate the level of genetic diversity in nuclear DNA. Introduction Edwards's Pheasant Lophura edwardsi is one of only four pheasant taxa currently classified as critically endangered according to the IUCN (1994) Red List Criteria (McGowan and Garson 1995, P. Garson, unpubl.). This is mainly a consequence of extensive habitat loss throughout its former range in the Annamese lowlands of central Vietnam. Several field surveys in Quang Tri and Thua Thien Provinces after the War failed to locate the species (Eames et al. 1992), which was consid- A. Hennache, E. Randi and V. Lucchini 396 ered extinct in the wild until its rediscovery in late 1996 (Eve 1997). The conserva- tion of Edwards's Pheasant, as well as two other critically endangered forms also endemic to this small area of Vietnam, the Imperial Lophura imperialis and Vietnamese Lophura hatinhensis Pheasants, is a high priority (McGowan and Garson 1995). Edwards's and Vietnamese Pheasants are currently breeding both in Vietnam and elsewhere. However, if these captive stocks are to constitute a valuable conservation resource for the future, they need extremely careful man- agement. Although generally considered to be a valid species (Collar et al. 1994), only slight plumage differences distinguish the Imperial and Vietnamese from Edwards's Pheasant. Thus it is important to determine their evolutionary rela- tionships in order to decide the extent to which they deserve separate conserva- tion action (McGowan and Garson 1995). The aims of this paper are to report on the extent of genetic variability in the Edwards's Pheasant captive stock, and to explore the molecular phylogenetics of these three Lophura taxa, with the object of contributing vital information to the process of defining a global conservation programme for them. However, our first task is to review all known historical information on the captive population of Edwards's Pheasant. The Edwards's Pheasant European endangered species programme In 1994, under the aegis of the World Pheasant Association (WPA), Han Assink and Alain Hennache accepted responsibility for running an International Stud- book for the Edwards's Pheasant, and initiated a European Endangered Species Programme (EEP) under the European Association of Zoological Parks and Aquaria (EAZA). This EEP now has 51 participants (18 different countries) man- aging about 300 birds. The declared aim of the Edwards's Pheasant EEP is to establish and maintain an ex situ population in order to preserve and maintain 90% of its original gen- etic diversity for a period of at least 100 years. The determination of the size of population required to achieve this result depends on the available historical information, including knowledge of the number of original founders, their breeding history and transfers, as well as information on the current population size and its growth rate. Moreover, reliable information on historical and current populations size and structure is critical for estimating the expected amount of genetic diversity that has been retained so far in the captive stock. The maintenance of genetic diversity is important for the viability of a captive population. Loss of genetic diversity, through random drift and the occurrence of inbreeding depression can threaten the survival of any small population, as a result of lowered reproductive performance and raised sensitivity to infectious diseases (Rails and Ballou 1986). It is also likely that some interspecific hybridiza- tion has polluted the captive stocks (Carpentier et al. 1975), making them unsuit- able for a conservation breeding programme. In response to these problems with the ex situ population of Edwards's Pheas- ant, a research agreement was signed in 1996 between the Museum National d'Histoire Naturelle (MNHN), Paris, France, and the Istituto Nazionale per la Fauna Selvatica (INFS), Bologna, Italy, with the aim of obtaining DNA sequence data on samples from wild and captive-reared Edwards's Pheasant with which to investigate these problems objectively. Genetic diversity of Edwards' Pheasant 397 Origin of the captive stock The first priority for the Edwards's Pheasant EEP was to review the historical information in an effort to determine the number of founders and their breeding and transfer history. The history of Jean Delacour's expeditions to Indochina, during which the first Edwards's Pheasants were collected, has been researched in detail by Ciarpaglini and Hennache (1995). Seven expeditions were organized between 1922 and 1939. At least 58-59 Edwards' Pheasants were collected during the first five expeditions in Quang Tri and Thua Thien Hue provinces between 1922 and 1929 (Table 1), although only 28-29 °f those, including just 9 females, were exported with certainty (Ciarpaglini and Hennache 1995). Three countries benefited from these imports: France (Cleres) in 1924, 1928 and 1930, Japan in 1926 and Great Britain in 1928. These c. 30 Edwards's Pheasants probably included the founders of the present captive population. However, since 1995, new information has become available indicating that Jean Delacour was probably not the only person to import this species from Vietnam. Three other possible sources are of importance (Ciarpaglini and Hennache 1997): (1) Walter Goodfellow imported Edwards's Pheasants and other Indochinese birds to England in 1936 (Anonymous 1936), but nothing more is known than this; (2) American soldiers, returning after the war in Vietnam, may have brought living Edwards's Pheasants to the U.S.A. (T. Lovel in litt., R. Sumner in litt.), but this is not properly documented anywhere to our knowledge; and (3) in the early 1980s, eggs of Edwards's Pheasants were received from Vietnam by a well-known private breeder in the former East Ger- many. From these eggs he reared two females one of which bred later with one of his captive males. According to Dang Gia Tung (pers. comm. 1996) the export of anything from central Annam was very difficult in the 1980s because of the widespread destruction of roads. It is therefore possible that these eggs came from northern Annam, within what is now known to be the range of the Vietna- mese Pheasant. Thus these females may have been Vietnamese Pheasants, and the captive stock of Edwards's Pheasant may therefore contain some hybrid lines. Some of the Edwards's Pheasants imported by J. Delacour bred soon after their arrival: in France in 1925, in Japan in 1927, and in England in 1929. In France, reproduction by captive Edwards's Pheasants was very irregular and Delacour did not produce as many Edwards's Pheasants at Cleres as he reported in the literature. Only 18-25 Edwards's Pheasants were certainly reared at Cleres between 1925 and 1939 (Ciarpaglini and Hennache 1997) and some of these were transferred to other breeders in France, Belgium, Germany and England (Ciarpaglini and Hennache 1997). No data are available for Japan. In England, John Spedan Lewis gave his first Edwards's Pheasant offspring to other English breeders (Ciarpaglini and Hennache 1997). Unfortunately the origin of the Amer- ican population is completely unknown. Documented transfers While the ornithological literature reveals the names of the breeders who obtained the first offspring bred from wild Edwards's Pheasants at Cleres, no records exist that allow us to pinpoint accurately the first transfers between con- tinents or countries. World War II destroyed most of the pheasant collections in Table 1. Edwards's Pheasant captures and importations between 1922 and 1929 Collectors Years Number Females known Males known Registered in Jabouille Localities captures known notes Jabouill 1922 3 1 2 o Hailang, Vinhlinh Jabouille 1922/23 4 0 4 o Hailang, Vinhlinh Delacour/Jabouille 1923/24 22 3 !9 (2,2) Camlo (No 15, 5, 19, 7) ; (3,0) Huong Hoa (No 16, 17, 18); (1,0) Ba Long (No 8); (1,1) Mailanh (No 20,10) Jabouille 1925 1 1 0 o Unknown Delacour/Lowe 1925/26 7 0 7 (2,0) Mailanh (No 19,282) ; (3,0) Langkhoai (No 945,946,947) ; (2,0) Hai Van Pass (No 1788,1789) Jabouille 1926 6/7 (including 1 4/5 - 1 (1,0) Langkhoai (No 180) ; 1 juv.