Veterinary Viewpoints


QUESTION #1: What is the best way to prevent male cockatoos from killing the females? I have lost three Moluccan hens this year already. I have 10-foot flights, double entry nest boxes, and I clip the males' wings. One of the pairs had been together for about seven years.

G. Smith, Hawaii

Answer #1: Aggression in cockatoos is very common. In the wild, if the male is too aggressive, the female at least has a chance to get a divorce by leaving. Breeding pairs of birds in confinement is not natural and since the birds rarely have a chance to choose their own partners, there is an increase in this aggression. Consider re-pairing your birds by selecting a tough hen for the aggressive male. Alternately, you might consider removing an aggressive cock bird from your breeding program.

fames M. Harris, DVM Oakland, CA

Answer #2: Mate aggression is probably the major reason for cockatoo death. It is· becoming an increasingly serious problem as the number of wild-caught male cockatoos declines. Your approach to controlling the problem is logical, but the problem usually lies with bonded cockatoo males.

Most of the breeding stock available is captive bred: therefore, most birds are "bonded" to humans rather than being socialized to their own kind. This is more of a problem with cockatoos than with other species such as Amazons or macaws, where hormones seem to take precedence over any psychological influences. If you have a captive-bred male, and he has demonstrated that he is a killer or abuser, it has been my experience that rehabilitating this bird is virtually impossible. Often, once a killer, always a killer.


This is why the market usually gets flooded with single male cockatoos shortly after the breeding season is over. Do not risk your hens with a known killer male: it's not worth it! Even though some birds have been together for some time, as with your pair which had been together for seven years, you cannot predict when aggression will occur. One approach you might try is to erect visual barriers between pairs or place unrelated birds such as African Greys between the breeding cockatoos.

Behaviorists speculate that the males in the wild come into breeding condition prior to females in order to establish territory. The females are free to fly away if undue aggression occurs, but this is obviously not the case in the aviary. If one male can see another, then territorial aggression ensues and the males may then displace that aggression onto their mates. This displaced aggression may become compounded when the bird is bonded to humans and confusion results when the bird comes into breeding condition.

The answer may be to find males which are parent-reared or have been allowed to flock with their own kind shortly after weaning such that the human-bird bond is broken. I have known instances where a Moluccan male is a good breeder and could be handled in the off-breeding season, but this is a rarity.

Hens also have this problem to some extent, but their maternal drive seems to override any bonding. However, the hens' problem is evidenced as inability to brood the eggs, refusal to feed, or even to killing the chicks.

We in aviculture must strive to produce more wild-type behaviors in birds through either parent rearing or by using techniques such as those used in zoos where animals are destined for release programs and not


Answer #3: Potential aggression is unfortunately commonplace amongst cockatoos kept in captive breeding situations. The aggression is usually in the form of serious or fatal attacks by the male to the hen. As with your own situation, the aggression in one pair of birds occurred following many years of captive enclosure. Many ideas have been suggested as to why the aggression occurs as well as ideas to aid in preventing these aggressive attacks. At this time, I am unaware of a foolproof method to guarantee survival of the female in all situations.

Ideas that have been utilized with varying degrees of success, include double entry nest boxes, long flights, tree branches for hiding places, clipping the males wings AND tail feathers, dulling the males maxillary tip (top bill), and placing older mature hens, with younger males.

Seclusion dividers between pairs may help. Allowing multiple pairs of birds to flock together in a large enclosure during non-breeding season and occasionally during the breeding season, and continual video monitoring of pairs, are additional suggestions.

At this time in our development as aviculturists, we have not yet arrived at better solutions for this sad and unfortunate occurrence. Successes achieved by an aviculturist hopefully will be willingly shared with other aviculturists to ensure that these species survive. In addition to Moluccans, it is not uncommon to have aggression in pairs ofRedvented, Citron-crested, and Ducorp's Cockatoos.