Abstract
My previous article (AFA Watch hi rd, Sept/Oct 2000) concentrated on the present day status and distribution of wild Brown-headed Parrots in Southern Africa. In that article, I mentioned that the reason for the demise of this species is, in part, that their preferred habitat is being lost. Here I will
concentrate on the annual cycle of the species illustrating the powerful link hetween the species and its hahitat.
The preferred hahitat consists of a light to medium dense shrub layer with an ahundance of taller trees of varying ages. However, this general description helies a numher of particular specific criteria.
Mating and Nesting Brown-headed Parrots hegin to mate in April, the heginning of the South African winter.
Although, the literature indicates that this is the time when the parrots choose mates, my research has shown that the pair hond is intact throughout the year. I will return to this suhject. There is strong hut circumstantial evidence that the pairs return to the same nest site each year.
The nest consists of a hole in an old tree. They are unahle to excavate the hole themselves and prohahly rely on insects or woodpeckers for the appearance of new nest sites. The cavities are highly prized commodities. I have seen hath hornhills and squirrels investigate a cavity whilst the Brown-headed Parrot chicks were still in situ and the parents sitting nearhy with no sign of alarm. On one occasion squirrels were seen moving nesting material into a cavity within an hour of the chicks departing.
Some authorities mention Adansonia digitata (Baobabs) as the principal tree species. This is incorrect. The species is not fussy, as long as the cavity is suit-
able. I have seen nests in Entandrophragma caudatum (Wooden Banana or Mountain Mahogany) Colopbospermum mopane (Mopani), Acacia nigrescens (Knobthorn), Afzetia quansensis (Pod Mahogany), and various Combretum species, as well as Baobabs. The parrots have no preference whether the tree is dead or alive.
A suitable hole is between 4 and 10 meters above ground, with the entrance around 10 to 12 ems in diameter. The hole may he in the trunk but if it is in a branch the hole should be facing the ground and have some sort of perch around a metre below. The hirds can then fly up and turn in the air. Nests in use show much scraping at the bottom of the hole where the adults have perched. No nesting material is used but if feathers are discarded at this time they are left in the nest.
Eggs and Babies
Two to three eggs are laid in late March or early April, with an interval of around two days between them. The incubation period is around 30 days and is solely hy the female. The male feeds the female at this point. The male alone continues feeding the babies after hatching and although the female brings food to the nest, she regurgitates this food to the male at a 'perch outside the nest. After feeding, the female enters the nest and carries out nest maintenance. Feeding is not regular.
Interestingly, although only the male directly feeds the chicks, they both return to the nest at the same time. If only one parent returns, it will sit on the perch close hy and call for its partner. If the partner does not tum up then it will leave without attempting to feed the chicks. This is interesting from a conservation point of view. If the parrots are being captured at this time then not only is one parent taken out of the system hut all of the chicks will probably die.
Around 50 days after hatching, the chicks leave the nest for the first and last time. They are then escorted to what I have termed a "nursery area." The nursery area consists of a few heavily foliated trees surrounding standing water, e.g., a dam, a river, etc. Each family of chicks occupies one of
the trees where they stay motionless and silent, however, they can move if alarmed. Parents return every three to four hours to feed them.
This finding led to an interesting question. If the chicks move, how do the parents find them? Through various playback experiments, it was found that the chicks recognize the voices of their parents. The incoming parents call as they approach and their chicks respond with their food begging call. This finding also means that the voice of each individual Brown-headed Parrot is individual, much the same as the voices of humans are distinct.
Feeding in the nursery area goes on for a further two weeks. At this point the chicks join their parents hut are still fed hy them for another fortnight. The chicks heg incessantly for food and are open to cheating. I have a recording of an "adult," which was busy eating some fruit. At the approach of two other hirds, it dropped the fruit, resorted to a chick food-hegging call, was fed hy what was presumahly its parents and, on their departure, it flew down, picked up the fruit and returned to adult calls.
Diet in the Wild
Chicks are fed various regurgitated seeds depending on availahility. The parents fed almost exclusively on the seeds of Cassia ahhreviata (Sjamhock pod) in the northern Kruger in 1997. But in 1998, that species failed to produce seeds and they fed on the seeds of Comhretum and Terminalia species.
By the time of the chick's independence at the heginning of summer, the parrots feed mostly on fruit as it becomes available. Important species at this time are Diospyros mespilliformis (jackal Berry) and as the summer progresses, Cassine aethiopica (Kooboo Berry) and Lannea stuhlmanni (False Marula). A surprising fruit utilized by the parrots in the south of the Kruger is Strycbnos madagascariensis (Black Monkey Orange). The fruit is around 10 cm in diameter and has a hard shell and soft peach like interior. The fruit is enjoyed by monkeys and baboons, which are able to rip open the hard shell to get to the interior. However, much of the fruit is discarded and the parrots fly to the ground to retrieve the
leftovers. Apart from drinking, this was the only time that I have seen Brownheaded Parrots on the ground.
Especially important in mid-summer is the fruit of Ficus sycamoros (Sycamore Fig). These huge trees, reaching 20 meters in height, produce enormous amounts of fruit and up to 50 birds may be seen feeding on one tree. This probably led to the erroneous conclusion that the species flocked in the summer and broke off into pairs prior to breeding. My research has shown that these flocks consist of paired birds and that the pair bond is intact throughout the year. Towards the end of summer, Brownheaded Parrots supplement their diet with caterpillars. They actively search for the cocoons, pick them off, discard the leaf and consume the whole animal. They also eat ants.
An important dietary item in the south of the Kruger is the fruit of Trichilia emetica (Natal Mahogany). This tree is especially prevalent in Pretoriouskop camp. The availability of fruit around the end of December attracts parrots into the camp and for over a month, Brown-headed Parrots are, if not the most common bird in the camp, certainly the most noisy.