The Laughing Thrushes (Garrnlax species)

Abstract

The 48 species in the genus Garrulax constitute one of the major groups of Asian passerines, and a number of species have held important places in aviculture. Garrulax canorus, the Melodious Jay Thrush or Hwamei has been a muchexploited cage bird in China for hundreds of years. The White-crested Laughing Thrush ( G. leucolopbus) and the Greater Necklaced Laughing Thrush ( G. pectoralis) were mainstays of both the Indian and Thai bird trades that flourished in the 1950s and '60s, the major sources of Asian passerines entering the U.S. in those decades.

Prior to the 1980s about half-adozen species in this genus were common commercial imports to this country (Bates & Busenbark, 1963). Other species showed up from time to time, especially out of Hong Kong. In the mid 1980s, a much richer variety of Garrulax species became available, when the People's Republic of China began large-scale commercial exports of birds. Traditionally, Laughing Thrushes (or Jay Thrushes, as they are just as commonly called) of one kind or another have been traditional zoo softbills for a long time.

From the accompanying table it will be seen that of the 15 species of Garrulax hatched in U.S. zoos in the period 1959 - 1995, only four commenced breeding before 1987. It is also interesting to note that the one species consistently bred during the 1970s, the White-crested Laughing Thrush, was hatched far less frequently in the late 1980s and '90s, as some of the novel species began to be propagated in numbers. Perhaps this is to be expected. At any rate, by the 1990s it was clear that some sort of program would be needed if any species was to be truly established in this country's zoos as a self-sustaining population. In 1994 the various Species Interest Committees of the Passerine Taxon Advisory Group (operating under the aegis of the American Zoo and Aquarium Association) were formed. The SIC for Laughing Thrushes was inaugurated with three people. The Species Interest Committee Organizer (SICO) is Jimmy Pichner, long-time Curator of Birds at the Minnesota Zoological Gardens, who also recently assumed responsibility for the Rothschild's Mynah studbook. The other participants were Christopher Brown, Curator of Birds at the Fort Wo1th Zoological Park, and Anita Cramm, Curator of Birds at Lincoln Park.

Out of the 18 species of Garrulax 'held by U.S. zoos as of 31 December, 1994, four were designated as target species species in the First Draft of the Passerine TAG Regional Collection Plan, which resulted from a two day meeting of SICOs at Seattle, in September of 1995. If the draft is approved as is, these will he the Laughing Thrush species that zoos will he encouraged to establish as self-sustaining populations.

White-crested Laughing Thrush

It was almost inevitable that one of these four is the White-crested Laughing Thrush. Quite aside from the fact that this species is striking-looking, hardy, an admirable songbird (performing duets), and typically stays out where people may enjoy it, it would be most annoying to not finally have something to show for all the specimens hatched in this country's zoos over more than 25 years, a total of 419 from 1968 through 1995.

Out of this total, however, at least 258 died before reaching adulthood. The problem of neonatal mortality remains a major problem. A contributing factor is the tendency for "the birds to re-cycle on to the nest quickly, and not to finish off the chicks after fledging" (Roth, 1993). The Minnesota Zoological Gardens has dealt with this by pulling chicks and handrearing them (Ibid, 1993). I have not heard whether hand-raising at this age leads to imprinting. While imprinted jay Thrushes make charming pets, they are certainly not the best of breeders and are definitely an escape risk in walk-through aviaries.

The White-crested Laughing Thrush breedings in U.S. zoos have definitely declined in recent years. Of the 29 collections that bred this bird in the U.S. from 1968 through 1995, 13 did so in the 1970s, 18 the '80s but only seven did in the '90s. A major reason has been the importation of other Garrulax species in recent years. Not only are these novelties colorful and otherwise attractive, most of them have proved to be markedly less aggressive than the White-crested Laughing Thrush.

The White-crested Laughing Thrush has a long-standing reputation for aggressiveness, especially when breeding. This has not prevented it being kept in all sorts of mixed aviaries, but caution is advised.

Unrelated White-crested Laughing Thrushes are notorious for aggression against members of their own species as well. The most detailed published account of the breeding of this species I am aware of concerns the repeated successes at the now-defunct Busch Bird Park in Houston (Young, 1978). This article is illustrative of the problems typical in working with this species. While the breeding records of the International Zoo Yearbook cover the years 1974 through 1976, breeding actually took place the previous two years as well. Not one of the of the 45 chicks hatched at the Bird Park over those five years were reared in an entirely normal fashion.

In July, 1971, six "newly purchased" specimens were liberated in the Bird Park's 3,000 m2 walk-through aviary. By June, 1972, only three birds were left, so six more newly purchased birds were introduced. Every one was killed by the original three in three days. It was then discovered that there was a nest with four chicks in a tree two meters off the ground (Young, 1978). All three adults fed the chicks. The chicks however succumbed to another prevalent source of neonatal mortality for....