Probosciger Research Articles

The phylogeography of palm cockatoos, Probosciger aterrimus, in the dynamic Australo‐Papuan region

AbstractAims We aimed to investigate the effects of historical land–sea boundary and vegetation dynamics in the Australo‐Papuan region on the genetic structure of palm cockatoo populations. In doing so, we also sought to clarify the intraspecific taxonomic status of palm cockatoos, and to examine the potential conservation implications of our results.Location New Guinea and northern Australia.Methods We examined mtDNA (domain III, control region) genetic structure in 71 palm cockatoos from 17 locations across their Australo‐Papuan range.Results Twenty polymorphic sites over 242‐base pairs defined 12 haplotypes that were arranged in a 95% confidence parsimony network of six one‐step clades. Half of these were linked in one clade that included birds from eastern New Guinea–Australia, and the other half included birds from western New Guinea. Nested clade analyses revealed strong and significant genetic structure between these two clades. The average nucleotide divergence between eastern and western birds is c. 3.3%. Within the western clade there was a non‐random distribution of haplotypes according to sampling location alone, but the locations did not cluster significantly, probably due to low sample sizes. A non‐random distribution of haplotypes emerged within one of the one‐step clades from the east of the range (once rare haplotypes were removed), although the historic mechanism that may have created this pattern is unclear. The underlying low nucleotide divergence (0.39%) among haplotypes within the eastern clade suggests relatively recent common ancestry.Main conclusions Our results suggest genetic isolation of the eastern and western clades sometime during the Pleistocene. The continual reappearance of land bridges associated with Pleistocene glacio‐eustatic cycles within the eastern part of the range provides an explanation for our results. We suggest that the occurrence of two deep marine troughs maintained a narrow mountainous barrier between eastern and western birds throughout much of the Pleistocene at a time when extensive land bridges formed elsewhere in the species’ range, and that this has maintained their genetic distinctiveness. Our results provide little support for the current accepted subspecies; the western clade is roughly congruent with Probosciger aterrimus goliath (with caveats), but the otherwise unstructured small genetic distances cast considerable doubt on the remaining subspecies. The eastern and western lineages are endemic to each area and should therefore be considered for independent conservation status and management.

The gradual loss and episodic creation of Palm Cockatoo (Probosciger aterrimus) nest-trees in a fire- and cyclone-prone habitat

We present information regarding the rate of loss of nest-hollows over a long period in the tropics, and a dramatic episode of nest-hollow creation following two tropical cyclones. We followed the fate of 61 Palm Cockatoo (Probosciger aterrimus) nest-trees over a period of 6 years (1999 to 2005). On average, 48 trees were monitored each year. During this time 16 (26.2%) were rendered unusable for Palm Cockatoos; their final cause of loss was fire (n = 10; 62.5%), wind (n = 4; 25%), and intense decay where the tree was left standing but unusable (n = 2; 12.5%). On average, 5.2% of nest-trees were lost each year. Dead trees were more likely to be destroyed than living trees. Individual Palm Cockatoos build nests in multiple hollows, a subset of which are used for actual breeding whereas the rest are used for display purposes only (inactive nest-trees). Inactive nest-trees were also more likely to be destroyed than active trees, suggesting Palm Cockatoos actually breed in nest-trees that are more durable. We revisited our study area in July 2006, following two severe tropical cyclones. Most of the known nest-trees that we visited after the cyclones were still standing. The first cyclone created ∼0.02 new nesting opportunities per hectare, whereas the second created 0.19. The differences between the two cyclones can be explained by their different paths and different radii of destructive winds in relation to our study area. While the loss of nest-trees owing to fire is significant, and should be monitored given that they are a limiting resource (Murphy et al. 2003), our results suggest that fire management should focus more on maintaining adequate recruitment of large trees, which could be affected by excessively frequent burning.

Abundance and habitat associations of parrots at a hillforest site in Papua New Guinea

Despite New Guinea's importance for parrot species, there is an almost total lack of quantitative data on abundances or habitat associations of parrots on the island. We present such data for 15 parrot species within the species-rich (21 species) Crater Mountain Wildlife Management Area, Papua New Guinea. The four most abundant parrot species made up 70% of all parrots recorded in primary forest and 76% in old gardens. Several species had estimated densities of 10?60 birds per km2 and we suggest that the most abundant species on New Guinea are at least as common as those on the surrounding islands. Two species of particular conservation importance, Palm Cockatoo Probosciger aterrimus and Pesquefs Parrot Psittrichas fulgidus had estimated densities of just one bird per km2, while several other notably rare species included Dusky Lory Pseudeos fuscata and the fig-parrots Cyclopsitta diopthalma and Psittaculirostris desmarestii. Most parrot species were strongly associated with the lower and flatter areas of the site, where mature secondary forest dominated. Again, this is a pattern shared with parrots on nearby islands, and the finding emphasizes the importance of protecting lower-altitude mature forests within the region.

Geophagy in birds of Crater Mountain Wildlife Management Area, Papua New Guinea

AbstractNumerous New Guinea birds, mostly psittaciforms and columbiforms, have been recorded feeding on soil. This study documents geophagy in the Crater Mountain Wildlife Management Area (CMWMA) in the Eastern Highlands of Papua New Guinea. We present the first documented case of geophagy in the palm cockatoo Probosciger aterrimus and in up to 11 other species. Soil from the site where geophagy by palm cockatoos was recorded was highly weathered and acidic, with a mixture of kaolin, gibbsite, goethite and illite in the clay fraction. Analyses may support the hypothesis that soil is ingested to counterbalance the effects of toxic compounds in fruit. We suggest that the accessibility of the site (an exposed bank), rather than the nature of the soil itself, prompted its use by birds. At another site, a blue‐coloured soil on which cassowaries fed was rich in vivianite (an iron phosphate) and contained an iron‐rich smectite, and some kaolin and mica in the clay fraction. Why cassowaries feed on this particular soil is unclear, but they may obtain trace elements from it, or take advantage of its high iron or phosphorus content. Obtaining other elements, in particular calcium and sodium, may also be important. Alternatively, there may simply be an attraction to its blue colour, which also attracted the interest of local people and folklore. Birds were also reported to drink salt water within the CMWMA. Taken together, there may be quite different reasons for ingestion of minerals/soils among as many as 23 bird species from five families.

Ground-foraging palm cockatoos (Probosciger aterrimus) in lowland New Guinea: fruit flesh as a directed deterrent to seed predation?

Fruit traits that selectively deter vertebrate seed predators without affecting high-quality seed dispersers are said to exhibit directed deterrence. Directed deterrence has been criticized as being unlikely in natural systems, but has rarely been explicitly tested. We evaluated the potential for directed deterrence to explain the double-layered viscous fruit morphology and fruiting phenology of Terminalia impediens, a common canopy tree endemic to New Guinea. The large fleshy fruits of this tree are consumed and dispersed by cassowaries (Casuarius spp.) and are consumed and killed by palm cockatoos (Probosciger aterrimus). Fruit flesh in this tree species appears to function as a deterrent to seed predation by palm cockatoos; the fruits of T. impediens fall to the ground before ripening, and are avoided by palm cockatoos until after the flesh has rotted off the hard nut. We found that palm cockatoos are able to prey upon seeds from fruits without flesh on the forest floor more efficiently than they can consume seeds from unripe fruit still on the trees. Further, through foraging preference tests, we found that palm cockatoos largely ignore seeds within ripe fruit on the ground, but readily eat the seeds when the fruit flesh has been removed. Cassowaries consume the fruit whole, when ripe, and defecate seeds in piles away from parent trees, where seed predation rates are lower. These results challenge the prevailing view that fleshy fruits evolved in tight synchrony with high-quality seed dispersers and add support to the non-exclusive hypothesis that aspects of fruit fleshiness may also have evolved as a response to seed predation.

The breeding biology of palm cockatoos (Probosciger aterrimus): a case of a slow life history

AbstractThe breeding of palm cockatoos Probosciger aterrimus was studied for 3 years from July 1999 to February 2002 in and around Iron Range National Park, Cape York Peninsula, Australia. Palm cockatoos were weakly seasonal breeders, with the peak of egg‐laying occurring in September; 41 breeding attempts were monitored at 28 nesting hollows. Nearly all (27/28) nests were in tropical savanna woodland and an average distance of 320 m to rainforest. Males defended about four nest sites, only a subset of which were used for breeding. The typical active nest tree was in a near‐vertical hollow with an opening that faced skywards; 62.1% of active nests were in living trees and the most common species of nest tree was Eucalyptus tetrodonta (48.3%). DNA fingerprinting revealed that some pairs reused the same nest hollow even when breeding attempts were separated by 1 or more years of no breeding activity, but that changes in hollow ownership also occurred. Nest usurpation, male territorial displays at the nest and evidence of interference competition by conspecifics suggest strong competition for nest sites, which is probably driven by variation in hollow quality and high investment in the nesting platform. Of active nests, 81% failed to produce a fledgling, thereby ranking the breeding success of palm cockatoos among the lowest reported for any species of parrot. They also invariably laid a single egg and seemed to breed infrequently, and thus they use an extremely slow life‐history strategy. We suggest that this slow life history makes palm cockatoos on Cape York Peninsula sensitive to environmental perturbations, with fire being the most probable threatening process.

Overlap and competition for nest holes among eclectus parrots, palm cockatoos and sulphur-crested cockatoos

We examined the extent of overlap in the characteristics of nest holes used by eclectus parrots (Eclectus roratus), palm cockatoos (Probosciger aterrimus) and sulphur-crested cockatoos (Cacatua galerita) in patches of rainforest and woodland in and around Iron Range National Park, Cape York Peninsula, Australia. Eclectus parrots nested only in rainforest and palm cockatoos nested mostly in eucalypt woodland adjacent to rainforest. Sulphur-crested cockatoos nested in both habitats. Nest holes of eclectus parrots and rainforest sulphur-crested cockatoos were in trees of larger DBH (diameter at breast height) and higher off the ground than those of palm cockatoos and sulphur-crested cockatoos in woodland. Palm cockatoos differed from the other parrots in their use of deeper holes with entrances that faced skywards rather than sideways. Both palm cockatoos and woodland sulphur-crested cockatoos used nests with smaller entrances than eclectus parrots and rainforest sulphur-crested cockatoos. All species showed intraspecific competition for nest holes. Behavioural conflict was also common between sulphur-crested cockatoos and the other two species. Each year 9.7–25.8% of eclectus parrot nests were taken over either permanently or temporarily by sulphur-crested cockatoos. Only one palm cockatoo nest was taken over by sulphur-crested cockatoos. Nest-holes were destroyed by natural causes at similar rates in rainforest (3.8% per annum over 174 nest-years) and woodland (5.4% per annum over 93 nest-years). Four nest trees fell over, and the floor of the nest collapsed at a further four holes. Three woodland nest trees burnt down during dry-season fires (August–October). New eclectus parrot and rainforest sulphur-crested cockatoo holes originated from incipient hollows on the tree that were modified by the parrots. We discuss the intense competition between these large parrots in light of the apparent shortage of appropriate nest holes in Cape York rainforest and eucalypt woodland.

Natural history, behaviour and captive management of the Palm cockatoo Probosciger aterrimus in North America

Habitat destruction, hunting and poaching for illegal trade are threatening the long-term survival of the Palm cockatoo Probosciger aterrimus. In 1983 the confiscation of 103 Palm cockatoos by the US Fish and Wildlife Service led to the formation of a breeding consortium, which in 1988 was formalized as an American Zoo and Aquarium Association SSP (Species Survival Plan). Details of the natural history, physical traits and behaviour of Palm cockatoos are given. Enclosure design, captive management and the development and goals of the Palm cockatoo SSP are also described.

Husbandry and breeding of Palm cockatoos Probosciger aterrimus at Rotterdam Zoo

Since the mid-1980s 22 Palm cockatoos Probosciger aterrimus (10.7 adults and 2.1.2 young birds) have been maintained at Rotterdam Zoo. Health problems and husbandry experiences with this species are recounted here. Nine (5.4) adults died, five within 2 years of acquisition through governmental confiscation. Three ♂♂were relocated to other zoos which had single ♀♀ Since 199! ten eggs (nine fertile) have been produced collectively by two ♀♀ with three ♂♂ Five eggs hatched, from which two chicks which were being hand-reared died, one at 6 weeks and one at 6 months of age. One chick was unsuccessfully fostered by a pair of Red-sided eclectus parrots Eclectus roratus polychloros and two chicks were successfully parent-reared: a ♀ in 1995 and a ♂ in 1997.

ULTRASTRUCTURAL, PROTEIN COMPOSITION, AND ANTIGENIC COMPARISON OF PSITTACINE BEAK AND FEATHER DISEASE VIRUS PURIFIED FROM FOUR GENERA OF PSITTACINE BIRDS

Psittacine beak and feather disease (PBFD) virus, was purified from diseased tissues of a lesser sulphur-crested cockatoo (Cacatua sulphurea), a black palm cockatoo (Probosiger aterrimus), a red-lored Amazon parrot (Amazona autumnalis), and a peach-faced lovebird (Agapornis roseicollis). The histopathology of diseased feathers and follicular epithelium from the different species was compared; basophilic intranuclear inclusion bodies were identified in the follicular epithelium and intracytoplasmic globular inclusions were observed within macrophages located in the feather pulp from the four species. Psittacine beak and feather disease virus antigen was specifically detected by colloidal gold immunoelectron microscopy. The different preparations of purified virions displayed an icosahedral symmetry, were non-enveloped, and had a mean diameter that varied from 12 to 15 nm when negatively stained. Two major viral-associated proteins with approximate molecular weights of 26 and 23 kilodaltons (kd) were consistently demonstrated from the four viral preparations. Purified virions from the four genera were antigenically related. These findings suggest that the PBFD virus purified from numerous genera of diseased birds is similar based on ultrastructural characteristics, protein composition and antigenic reactivity.

A cytogenetic study of four species of cockatoos and Amazon parrots

The karyotypes of three species of cockatoos, Cacatua moluccensis, Cacatua goffini, and Cacatua sanguinea, and one Amazon parrot, Amazona aestiva, are described for the first time. These karyotypes are compared to the twenty-three species of psittacines published previously. Cacatua moluccensis appears to be a link in the evolutionary tree between Probosciger aterrimus and the other cockatoo species studied. This study reaffirms that the cockatoos are probably most closely related to the loris (Loriculus sp.) and Amazon parrots based on karyotype (M. W. M. Van Dongen & L. E. M. De Boer, (Genetica 65: 109–117) 1984).

Chromosome studies of 8 species of parrots of the families Cacatuidae and Psittacidae (Aves: Psittaciformes)

The karyotypes of 7 species of Psittaciformes new to cytology are described: Cacatua galerita, Calyptorhynchus magnificus and Probosciger aterrimus of the Cacatuidae, and Ara macao, A. ararauna, Amazona viridigenalis and Psittrichas fulgidens of the Psittacidae. For reasons of comparison the karyotype of Melopsittacus undulatus is also described. These karyotypes are compared to 8 psittaciform karyotypes previously recorded. There is a remarkable heterogeneity of karyotypes in the Psittaciformes. Nevertheless, it seems possible to recognize Cacatua, Calyptorhynchus and probably also Probosciger (Cacatuidae) by their karyotypes as a clearly related group. The karyotypes of these cacatuids also bear some resemblance to that of Loriculus (Psittacidae). The psittacid genera Amazona, Ara, Nestor, Melopsittacus, Psittacula, Psittacus and Psittrichas are karyologically heterogeneous, but their karyotypes show certain relationships. The karyotype of Brotogeris is very different from those of other psittacids.

Breeding the Palm cockatoo at Sydney Zoo

Breeding the Palm cockatoo at Sydney Zoo

Some Field Observations on the Great Palm Cockatoo

SummaryThe Great Palm Cockatoo, Probosciger aterrimus, was the subject of limited observations, during November 1963, at Iron Range, North Queensland, and a brief account is given of its habitat, behaviour, feeding and nesting.

Additional Notes on a Great Black Palm Cockatoo in Captivity

Additional Notes on a Great Black Palm Cockatoo in Captivity