Tuesday, 28 February 2017

The Yellow-crested or Lesser Sulphur-crested Cockatoo. Part 6. Captive Breeding

This is the 6th and final  of a series of articles on this once common but now critically-endangered species from the islands of Indonesia and of Timor Leste.


The quaint behaviour of the Avicultural Society, an organisation founded in U.K. in 1894, allows us to find very easily when a species was first bred in U.K. The Society gave a medal for the first breeding of a species and often a subspecies. In these more enlightened times a medal might be deserved for breeding an endangered species for a number of generations while keeping inbreeding to a minimum but I suppose the idea of a medal appealed to the many super-rich members in the aristocracy as well as the nouveau-rich industrialists and retailers who often had enormous collections of birds in their stately homes and who competed with one another to obtain the rarest birds from all over the world.

The first record of the Yellow-crested Cockatoo breeding in captivity in U.K. was reported in Avicultural Magazine in 1924. The breeder was M.T. Allen and the medal was given for breeding the subspecies C. sulphurea sulphurea. I have not seen the article.

By chance I do have copies of the Avicultural Magazine reporting the breeding in 1955 and 1956 of two other subspecies, namely, the Citron-crested (C. s. citrinocristata) and what was named as the Timor Cockatoo, C. s. parvula. The breeder in both cases was S.B. Kendall.

Dr Stanley Brian Kendall PhD MRCVS ARCS FIBiol (1915-1999) was a veterinary parasitologist then working at the Central Veterinary Laboratory in Weybridge, Surrey. Like many veterinary graduates of his day he worked in Africa as a Colonial Veterinary Officer for a time, in this case Tanganyika from 1943 to 1947. He lived in Chertsey, Surrey and joined the Avicultural Society in 1953.

By the 1950s the membership of the Avicultural Society was more mixed. There were still members of the aristocracy but the annual list shows zoo directors and curators, museum people, scientists and a great many private bird keepers and breeders. The tendency was for the latter not to be bird ‘fanciers’ who exhibit artificially selected birds competitively nor pet bird keepers. The Society was—and still is—a cut above those pursuits.

Kendall’s first article begins:

     The Citron-crested Cockatoo has always been a rare bird in captivity, presumably as a result of its limited distribution (Sumba Island), but during the temporary lifting of the ban [because of a risk of psittacosis to the public] on the importation of parrots in 1952-1953 a number reached this country. There are at present several odd males in different hands, but the hens are unfortunately very few.

He then went on to describe the simple outdoor aviary, the introduction of potential nest boxes, how the birds were fed and then the nesting and appearance of two young.

His second article is entitled, Breeding the Timor Cockatoo. And this is where I have trouble in knowing which of the currently recognised subspecies he actually bred. The candidates are, of course, parvula from Timor and occidentalis from the islands west of Timor, from Alor to Lombok.
The fact that they were clearly known in the early 1950s as Timor Cockatoos might suggest they were parvula. But this is what Kendall had to say:

     Timor Cockatoos are similar to the better-known Lesser Sulphur Cockatoo [sic]. from which they can be distinguished by the considerably less well developed areas of sulphur-yellow on the back of the head and cheek, and by the virtual absence of yellow on the chest and belly. In addition, they are markedly smaller; hens are often really tiny and must be the smallest cockatoo that exists.

I take this paragraph to indicate that C.s. sulphurea was sometimes imported from Sulawesi but again I have difficulty in deciding whether his birds were occidentalis or parvula, although the size might suggest parvula. But whether his birds really were parvula in the present definition I still doubt, especially since in another paragraph he wrote:

     As the popular name suggests, the main home of parvula is in Timor Island. Skins in the Natural History Museum, South Kensington, are labelled East Timor, South Flores, Pantar and Lombok…

In other words, the Museum was not recognising Hartert’s distinction between parvula and occidentalis.

I doubt we shall ever know the origin of Kendall’s birds that were imported into Britain in May 1952 unless, of course, somebody out there has records or photographs.

Kendall’s pair of cockatoos, treated in much the same way as his Citron-crested, produced two young.

As an example of coincidence I found while writing this article, Kendall’s medal from the Avicultural Society for breeding C. s. parvula for sale on eBay.

One  of S.B. Kendall's Avicultural Society Medals
for sale on eBay in Fenruary 2017

It was established that C. sulphurea could be bred—and would breed pretty easily. In part 2 of this series I mentioned Lindholm’s survey of parrots bred in American zoos between 1959 and 1994; 20 Yellow-crested Cockatoos were bred in 5 zoos; 50 Citron-crested in 11 zoos.

However, with all cockatoos, a major problem emerged: incompatibility of potential breeding pairs. In seemingly compatible pairs the male would kill the female without warning. Amongst a number of recommendations were that a number of cockatoos of the same species should be brought up together so that pairs could form naturally. However, other problems seemed to be associated with hand-rearing. Some cockatoos were taken from the nest and hand-reared. They, along with many other animals treated in such a manner, became totally confused as to their identity, living in some warped social structure between human and cockatoo. That problem has been exacerbated by the virtually complete hand-rearing of cockatoos from hatching in order to produce ‘tame’ (for a while) birds for the pet trade. These birds, imprinted on their human rearer and weaned onto adult food too soon, are simply but sadly crazy.

The Baby Cockatoo Industry

The industry—and it is an industry particularly in the U.S.A.—of production line, hand-reared birds for people besotted by baby cockatoos is a dead end as far as proper aviculture or captive breeding for conservation is concerned, and a life of confused misery for the individual cockatoo. Rosemary Low who is a world expert on parrots in captivity writes on her website:

     Can there be anyone who reads parrot magazines who is not aware of the fact that white cockatoos are too demanding to make suitable pets? That is putting it mildly.  Many, perhaps even the majority, of these highly intelligent and (when young) irresistibly appealing birds, end up as unwanted or abused. They develop serious psychological problems that manifest themselves in problem behaviours such as biting, screaming and feather plucking…
     …I already asked the question is there really anyone in the parrot world who does not know what is in store for most hand-reared white cockatoos?  Even ten or 20 years ago real parrot lovers were misguidedly hand-rearing these birds. Now that the problem is so well known, and parrot rescue facilities with sad, plucked and demented socially-deprived cockatoos are even seen on TV programmes, only the commercial breeder who cares more for money than for birds, continues to hand-rear them…
     The misery will end only decades after white cockatoo breeders shut up the nest-boxes forever. Even if that happened tomorrow, the supply of sad and abused birds to refuges would not dry up for another 50 years. Some people are dedicating their lives to repairing the damage that breeders have done. Cockatoo breeders: please take your heads out of the sand where they have been buried for at least a decade. The blame lies firmly on your doorstep. If you really love cockatoos you will stop breeding them now. And parrot owners, if you love them you will stop buying them from breeders. Only if there is no demand will the market dry up and the misery end.

Conservation Breeding

There is one saving grace for those who began an interest by having a pet cockatoo or other parrot. They have realised that many species have become endangered. Together with private aviculturists and those in zoos who seek to perfect proper captive breeding (i.e. without hand rearing) they provide a useful lobby to campaign and to raise money for conservation in the wild as well as ex situ.

Collar & Butchart of Birdlife International, in an excellent paper in International Zoo Yearbook in 2014 on captive breeding of birds for conservation include C. sulphurea in the ‘precautionary’ category. 

European Zoos have an EEP (European Endangered Species Programme) for the Citron-crested subspecies (C. s citrinocristata) but that does not include any of the equaly endangered Yellow-crested subspecies.

The European Zoos have produced guidelines for the husbandry of ‘white’ cockatoos in the various breeding programmes. However, the guidelines seem to me to place too much emphasis on artificial incubation of the eggs and hand rearing. Successful captive breeding (‘the discipline and practice of nurturing animals successfully through the reproductive cycle in captivity’ as defined by Collar & Butchart) is not achieved if eggs have to be incubated and/or chicks have to be fed by human hands. Parental care is part of the reproductive cycle. If the parents do not perform that task then captive breeding has failed even though chicks have been produced; the fault lies with the keeper who has not provided the correct conditions and needs to do more research and perhaps needs to spend a lot more money to get them right. 

In conclusion, given the relative ease of breeding C. sulphurea, as exemplified by Kendall in the 1950s, I have no doubt that given sufficient resources a successful captive breeding/reintroduction programme could be successful—but only as a last resort and only if the remaining habitat could support a population.


Finally, it is worth reading Dr Siti Nuramaliati Prijono’s* case study on C. sulphurea in Indonesia written in 2008 showing the state of the various populations up to 2005 and the conservation measures that were needed. It would be informative to have a follow-up study to see what has happened on the ground in the last ten years.

*Dr. Siti Nuramaliati Prijono has been Principal Secretary of the Indonesian Institute of Sciences since 2014. We were once near neighbours when she was working at the Scottish Agricultural College at Auchincruive.

Collar NJ, Butchart SHM. 2014. Conservation breeding and avian diversity: chances and challenges. International Zoo Yearbook 48, 7-28.

Kendall SB. 1955. Breeding the Citron-crested Cockatoo. Avicultural Magazine 61, 226-229.

Kendall SB. 1956. Breeding the Timor Cockatoo. Avicultural Magazine 62, 6-9.

Lindholm JH. 1999. An historical review of parrots bred in zoos in the USA. Avicultural Magazine 105, 145.

O’Brien J. 2007. EEP Husbandry Guidelines for Cacatua spp. 2nd edition.

Prijono, S. N. (2008). Case Study: Cacatua sulphurea. NDF Workshop. https://cites.org/sites/default/files/ndf_material/WG6-CS4.pdf