From the field: Conservation Down Under Aussie Aviculturists Aid Endangered Pigeon

Abstract

0 ver recent years there has been a marked evolution in the way birds are kept. Advances in medication, nutrition, and housing have significantly improved the hobby and led to a huge increase in the numbers of birds successfully raised to maturity.

Another advance has been in the overall approach by aviculturists to obtaining stock. With more and more countries banning the export of their native species, birdkeepers have been forced to rely on their own breeding efforts to replace and maintain species in captivity.

Also, there has been a growing trend towards "conservation aviculture," such as the programs involving Spix's Macaw Ara spixii and the Blackhooded Red Siskin Carduelis cucullata. Now a project by the Conservation Committee of the A vicultural Federation of Australia (CCAFA) is tackling species not as highly endangered as these, but nevertheless in need of close scrutiny, both in captivity and in the wild. The charter of the CCAFA is to monitor species it sees as vulnerable in captivity and in the wild, produce life tables, identify and encourage pure species management (to avoid and eliminate hybridization), conduct censuses, maintain stud books, conduct population and habitat

viability assessments and produce husbandry manuals for birds the previous categories indicate as needing help.

This is tied to efforts to assist the conservation of the species in its natural habitat, or in the case of foreign species in situ captive breeding programs in co-operation with local aviculturists or relevant government agencies.

The first husbandry manual produced in Australia was for the Luzon Bleeding- heart Pigeon Ga!licolumba luzonica, which as the name suggests is native to the Philippines. It is one of the most attractive of the foreign pigeons and doves kept in Australian aviaries.

William L. R. Oliver, principal coordinator of the Threatened Endemic Species Conservation Projects, speculates that the Luzon Bleeding-heart Pigeon kept in Australia may be G. !. griseolateralis from northern Luzon - the least threatened of the bleedingheart taxa as it occurs in areas where there is still a reasonable coverage of lowland forests, the bird's preferred habitat. However, pressure from a burgeoning population and continued massive deforestation must place the bird's existence in dire jeopardy.

The Philippines consists of around 7100 islands, covering a land area of 117,000 sq miles, only a few of which are suitable for human habitation. This causes extreme pressure on their native birds and animals as they must share their habitat with almost 67 million people living in an area equal to only 4% of Australia. It is not surprising then that all of the five species and six subspecies of bleeding heart pigeons are threatened, some critically.

The Luzon Bleeding-heart is the only subspecies represented in Australian aviaries, although earlier this century a few Bartlett's Bleeding-hearts Gallicolumba criniger bartletti were held by local aviculturists.

Bleeding-hearts do best in a planted aviary. Like all pigeons, they can be flighty and prone to flying wildly about the aviary when disturbed. A wellplanted aviary, which replicates their natural habitat provides the birds with a sense of security and makes them less likely to take flight in panic. Palm grass Curculigo and Elephant's Ear

Alocasia are two plants worth considering. Being broad-leaved plants, they should not be planted beneath perches where they would soon be covered in unsightly droppings.

A suitable aviary could be 18 ft. long x 6 ft. wide x 6 ft. high, with about one third shelter. Having the front perch low and the perch in the shelter up higher will encourage the birds to roost at night in the shelter and not in the open flight section of the aviary.

There is very little sexual dimorphism (enabling one to sex birds by sight) in bleeding-hearts, especially to the novice breeder, which makes visual differentiation unreliable. With an adult pair, the cock bird appears slightly larger, cobbier; his head is broader and the red chest patch . brighter and more extensive. The under parts of the hen tend to show more buff and, if she has laid, the vent bones are wider apart. DNA sexing is not yet viable for bleeding-hearts.

Two surgical procedures offer better alternatives, both should be carried out by a qualified veterinarian. A seminal papillae examination through the vent will show in a male two papilla (small nipple-like projections) which exude semen. In a female the papillae are either absent or very small.

The most reliable procedure is surgical sexing, where the internal sexual organs are examined with a fibre optic laparoscope. A small incision is made in the side of the bird through which the laparoscope in inserted. Depending on the sexual maturity of the birds, the testes or ovaries are easily seen and an accurate determination of sex made. To carry out the procedure the bird is put under anaesthesia but even in a bird as nervous as a bleeding-heart the operation carries very little risk.

In southern Australia the birds have a break from breeding between March and July (i.e. autumn to early winter). During the year I feed the bleedinghearts com kernels, cheese and plain cake every day (as well as the normal seed mix). Come September, I start feeding livefood in the form of mealworms, as well as whatever other insects are around - flour moth grubs, earthworms, to help trigger off

the breeding cycle.

My pairs choose to build a nest on a platform of dry shrubs at the back of the shelter. The nest is typical of pigeons, a flimsy structure made of twigs and dry palm grass fronds. Two eggs form the clutch, each measuring around 27.5mm x 20.75mm and weighing 6.25 grams. Incubation lasts around 17-18 days, and is shared by both birds - the hen at night and both the cock and hen during the day. Bleeding-hearts are prone to deserting their eggs if disturbed, but become more tolerant when young are in the nest. It is best, however, to leave well enough alone and not disturb them.

The fact that the bleeding-heart can be such a temperamental bird has caused many breeders to foster deserted eggs under other pigeons and doves - domestic pigeons, Greenwinged Pigeons, New Guinea Ground Doves and, perhaps the most popular, the Ring-neck Dove. To do this, however, you need quite a few pairs of foster parents if you are to match their breeding cycle with that of the bleeding-heart pair.

The young leave the nest at around 16 days and spend their first 8-10 days on the floor before perching. At this stage the young chicks are a russet brown with three chestnut wing stripes. They appear all wings, as their body and neck feathers are not as well developed. During these first few days the parents roost on the ground with the chicks at night.

At around 12 weeks the chick have a dirty adult plumage and the red patch is beginning to appear. This is the best time to remove them from their parents.

Unlike its perilous state in the wild, the future of the Luzon Bleeding-heart Pigeon in Australian aviaries seems secure. A husbandry manual (compiled and edited by C.A. Hibbert) has been produced; a census and a possible stud book are planned. The census may show more than 500 bleedinghearts are currently kept in Australian aviaries.