Probosciger Research Articles

Sexy tools: Individual differences in drumming tool shape.

Heinsohn et al. Proceedings of the Royal Society B, 290, 2023.1271, (2023) report that the choice of tool type (drumsticks or seed pods) and the shape of drumsticks manufactured by palm cockatoos differ among individuals. This variation does not seem to be culturally transmitted as no spatial correlation between proximity of display trees and tool shape was found.

Individual preferences for sound tool design in a parrot.

The rarity of tool manufacture in wild parrots is surprising because they share key life-history traits with advanced tool-using species, including large brains, complex sociality and prolonged parental care. When it does occur, tool manufacture in parrots tends to be innovative, spontaneous and individually variable, but most cases have been in captivity. In the wild, only palm cockatoos (Probosciger aterrimus) have been observed using tools regularly. However, they are unusual because they use tools to enhance their displays rather than for foraging or self-maintenance. Males in northern Australia make two types of tool from sticks and seed pods, which they tap rhythmically against a tree during display. We analysed 256 sound tools retrieved from 70 display trees. Drumsticks (89% of tools) were used more often than seed pod tools; most males manufactured only drumsticks, but some made both types. Individual males differed significantly in the design of their drumsticks including the length, width and mass but we found no evidence that neighbours copied each other. We discuss the highly individualized preferences for sound tool design in context of the behavioural predispositions behind the rarity of tool manufacture in wild parrots.

Field methods to identify Palm Cockatoo nest hollows

Within Australia, the iconic Palm Cockatoo Probosciger arterrimus macgillivrayi occurs only on the Cape York Peninsula, Queensland, has recently been listed as Endangered, and requires large, old hollow-bearing trees for nesting. Surveys for these trees are crucial for management purposes. Typical surveys rely on following auditory (vocalisations) and visual (sightings) cues to determine the presence of birds or nests. However, nesting hollows can easily be inadvertently overlooked during such surveys because of false absences caused by biennial nesting, decreased vocal activity during nesting, and silent flushing from active nests when approached. We developed a systematic, grid-based transect methodology that maximises the likelihood of identifying potential, used, and confirmed Palm Cockatoo nest hollows and this has been implemented on western Cape York Peninsula since 2015. This method does not rely on bird presence at the time of surveys, but instead relies on multiple, specific signs of recent Palm Cockatoo nesting activity, to the exclusion of other large, sympatric parrots. We tested this method on novice observers and found that it enabled them to rapidly learn how to detect Palm Cockatoo hollows in the landscape. Thus, for ecological surveys on Cape York Peninsula, we propose that this method should supersede previous auditory/ visual surveys to identify Palm Cockatoo nesting sites, and we hope that this improves the conservation of this species in Australia.

Detection of infectious bronchitis-like virus isolated from psittacines at breeding facilities

Abstract. Suryaman GK, Soejoedono RD, Poetri ON, Setiyono A, Handharyani E. 2021. Detection of infectious bronchitis-like virus isolated from psittacines at breeding facilities. Biodiversitas 22: 4261-4265. Captive breeding of parrots has been carried out in Indonesia to fulfill market demand for pets and support conservation efforts. However, there is limited information about Infectious Bronchitis Virus (IBV) in captive parrots. Therefore, this study examines IBV virus in psittacines and observes the pathological changes in inoculated chicken embryos. Cloacal swabs were obtained from 31 psittacine birds consisting of 15 sulfur-crested cockatoos (Cacatua sulphurea), 10 palm cockatoos (Probosciger aterrimus), two blue and yellow macaws (Ara ararauna), two green-winged macaws (Ara chloropterus), and two scarlet macaws (Ara macao). Swabs were also injected for 9 days to obtain specific pathogen-free (SPF) embryonated chicken eggs, and allantoic fluids were collected after 7 days. The residual cloacal swabs and allantoic fluid samples were tested for IBV by reverse transcription polymerase chain reaction (RT-PCR) targeting spike 1 glycoprotein (S1) and nucleoprotein (N) gene by primer set XCE2+/XCE2- and IBVN+/IBVN-, while the harvested inoculated embryos were examined for histopathological lesions by hematoxylin-eosin staining. Three and one allantoic fluid of C. sulphurea and P. aterrimus respectively were found positive for IBV by primer set IBVN+IBVN-. However, there was no significant difference in the inoculated embryo's gross anatomy, and the slight histopathological changes observed were not caused by the virus. Therefore, it is unclear whether the IB-like virus causes clinical disease manifestation in both Psittacine species or the chicken embryo. This is the first study carried out on IB-like viruses for both species.

Slow breeding rates and low population connectivity indicate Australian palm cockatoos are in severe decline

Dispersal dynamics can determine whether animal populations recover or become extinct following decline or disturbance, especially for species with slow life-histories that cannot replenish quickly. Palm cockatoos (Probosciger aterrimus) have one of the slowest known reproductive rates of any parrot, and they face steep decline in at least one of three populations comprising the meta-population for the species in Australia. Consequently, we estimated demographic rates and population connectivity using data from published field studies, population genetics, and vocal dialects. We then used these parameters in a population viability analysis (PVA) to predict the trajectories of the three regional populations, together with the trajectory of the meta-population. We incorporated dispersal between populations using genetic and vocal data modified by landscape permeability, whereby dispersal is limited by a major topographical barrier and non-uniform habitat. Our PVA models suggest that, while dispersal between palm cockatoo populations can reduce local population decline, this is not enough to buffer steep decline in one population with very low breeding success. The small population size and likely decrease in the meta-population of greater than 50% over three generations (49 years) supports a change of conservation status for Australian palm cockatoos from ‘Vulnerable’ to ‘Endangered’ under IUCN criteria. Our research provides an important demonstration of how PVA can be used to assess the influence of complex meta-population scale processes on the population trajectory of species that are challenging to monitor.

Modelling dispersal in a large parrot: a comparison of landscape resistance models with population genetics and vocal dialect patterns

Identifying the range, core areas and dispersal pathways or barriers in heterogeneous landscapes is important for managing threatened species. Studies of variation in learned vocalisations are a promising complementary tool to traditional landscape genetics studies for identifying potential dispersal barriers. Here we use multiple data sources to inform the conservation of a parrot species. We tested for correlations between landscape resistance models, population genetic structure and vocal variation of parrots to investigate the effects of natural barriers on genetic and behavioural population structure including narrow habitat corridors and a mountain range. We studied palm cockatoos (Probosciger aterrimus) within their Australian distribution. We constructed landscape resistance surfaces restricted to areas of high climatic suitability from a maximum entropy (MAXENT) distribution model. We verified three landscape resistance predictions from CIRCUITSCAPE (isolation by elevation, habitat and distance) using four data sets (individual genetic divergence, acoustic divergence in repertoire and two call types). Landscape resistance models revealed strong effects of isolation by elevation on genetic, repertoire and structural call differentiation. Neither isolation by habitat nor isolation by distance were well supported by differentiation in the data. Our landscape resistance analysis validated by four datasets supports the Great Dividing Range as the main limitation on dispersal and connectivity among palm cockatoo populations. Combined genetic and behavioural approaches can determine landscape-level connectivity of individuals and demonstrate how dispersal barriers influence genetic and behavioural patterns in a large parrot.

Molecular techniques for sex identification of captive birds.

Background and Aim:Many avian species are considered sexually monomorphic. In monomorphic bird species, especially in young birds, sex is difficult to identify based on an analysis of their external morphology. Accurate sex identification is essential for avian captive breeding and evolutionary studies. Methods with varying degrees of invasiveness such as vent sexing, laparoscopic surgery, steroid sexing, and chromosome inspection (karyotyping) are used for sex identification in monomorphic birds. This study aimed to assess the utility of a non-invasive molecular marker for gender identification in a variety of captive monomorphic birds, as a strategy for conservation.Materials and Methods:DNA was isolated from feather samples from 52 individuals representing 16 species of 11 families indigenous to both Indonesia and elsewhere. We amplified the chromodomain helicase DNA-binding (CHD) gene using polymerase chain reaction with MP, NP, and PF primers to amplify introns with lengths that differ between the CHD-W and the CHD-Z genes, allowing sex discrimination because the W chromosome is exclusively present in females.Results:Molecular bird sexing confirmed 33 females and 19 males with 100% accuracy. We used sequencing followed by alignment on one protected bird species (Probosciger aterrimus).Conclusion:Sex identification may be accomplished noninvasively in birds, because males only have Z sex chromosomes, whereas females have both Z and W chromosomes. Consequently, the presence of a W-unique DNA sequence identifies an individual as female. Sexing of birds is vital for scientific research, and to increase the success rate of conservation breeding programs.

Breeding biology of three large, sympatric rainforest parrots in New Guinea: Palm Cockatoo, Pesquet’s Parrot and Eclectus Parrot

ABSTRACT In New Guinea Palm Cockatoos, Pesquet’s Parrots and Eclectus Parrots are potentially threatened by deforestation and hunting. In a 28-month study, we found 51 Palm Cockatoo, 34 Pesquet’s Parrot and 71 Eclectus Parrot nests. Eclectus Parrots used taller, larger, live trees. Palm Cockatoos preferred hollows in broken trunks having deeper hollows with larger entrances. Pesquet’s Parrots excavated their nest hollows in dead trees. Palm Cockatoos nested at lower density (0.008 nests/ha) than Pesquet’s (0.022 nests/ha) and Eclectus Parrots (0.069 nests/ha). Palm Cockatoos and Pesquet’s Parrots appeared to breed seasonally; Eclectus Parrots bred at higher frequency year-round. Palm Cockatoo clutch size was one; Pesquet’s and Eclectus Parrots clutches had one to two eggs. Eclectus Parrots had higher fledging success: 54%, compared with 40% of Palm Cockatoo and 17% of Pesquet’s Parrot eggs. Predation caused most nest failures for Palm Cockatoos and Eclectus Parrots; starvation caused most loss in Pesquet’s Parrots. Humans hunted Palm Cockatoos and Pesquet’s Parrots, not Eclectus Parrots. Higher nest tree density, breeding success, and more generalised feeding habits may make Eclectus Parrots the least vulnerable of the three species. Low population density and breeding frequency of Palm Cockatoos and Pesquet’s Parrots may make them more vulnerable.

Pengetahuan Konservasi Tradisional Burung Endemik pada Masyarakat Kampung Soaib di Distrik Kemtuk, Kabupaten Jayapura

This study was to investigate the endemic birds, local knowledge and the conservation efforts on the bird species. The study was conducted in the period from February 2007 to May 2008. Methods used including observation, interviews, documentation, description and literature review. The results showed that there were 11 spesies of endemic birds occured in Soaib village: Cassowary (Casuarius unappendiculatus), Yellow-crested Cockatoo (Cacatua galerita), two species of Megapodes; (Aypepodius arfakianus) and (Megapodius freycinet), Papuan Hornbill (Rhyticeros plicatus), Victoria Crowned-pigeon (Goura victoria), Palm Cockatoo (Prombosciger atterimus), Parrot (Psittrichas fulgidus), Papuan crow (Cracticus cassicus) Bird of Paradise (Paradiseae sp). Local people determined the forest in three different types; primary forest, buffer zone between primary and secondary forest and secondary forest. Primary forest was being the habitat for 11 endemic birds. These birds were hunted by local people for meat consumption and cultural purposes excepted the Papuan hornbill (Rhyticeros plicatus) and Papuan crow (Cracticus cassicus). Bird of Paradise (Paradiseae sp), and yellow-crested Cockatoo (Cacatua galerita) were captured to be sold in the market. This was happened because of lack information and education about the role of the birds in forest ecosystem. Key words: Traditional conservation, endemic birds, Soaib village, JayapuraÂ

Genomic population structure aligns with vocal dialects in Palm Cockatoos (Probosciger aterrimus); evidence for refugial late-Quaternary distribution?

ABSTRACTSpecies persistence and maintenance of genetic diversity are strongly affected by dispersal and historical distribution, especially when species depend on habitat that is non-uniform or fluctuates dramatically with changing climate. Australo-Papuan rainforest has fluctuated dramatically since the last glacial maximum (around 20 kya). To understand how prehistoric climate fluctuation affected population connectivity and genetic diversity in a rainforest edge species, we screened 27 Palm Cockatoo samples from Cape York Peninsula (Australia) and southern Papua New Guinea (PNG) in 1132 single nucleotide polymorphisms in 342 nuclear loci and the mitochondrial ND2 gene. We also modelled the birds’ distribution at present, mid-Holocene (~6 kya) and the last glacial maximum (~21 kya). Population differentiation in nuclear genomic data among Australian populations aligns with distribution contraction to mountainous refugia at the mid-Holocene (~6 kya). Lack of nuclear divergence between PNG and Australia may reflect late-Holocene recolonisation, but different ND2 haplotypes suggest early stages of divergence. Although admixed individuals suggest some gene flow, recent movement restriction to/from Australian refugia is suggested by a unique ND2 haplotype, genomic divergence and a vocal dialect boundary shown previously. Our results show how prehistoric climate fluctuation affects present-day and future species conservation in dynamic rainforest edge ecosystems.

Tool-assisted rhythmic drumming in palm cockatoos shares key elements of human instrumental music.

All human societies have music with a rhythmic "beat," typically produced with percussive instruments such as drums. The set of capacities that allows humans to produce and perceive music appears to be deeply rooted in human biology, but an understanding of its evolutionary origins requires cross-taxa comparisons. We show that drumming by palm cockatoos (Probosciger aterrimus) shares the key rudiments of human instrumental music, including manufacture of a sound tool, performance in a consistent context, regular beat production, repeated components, and individual styles. Over 131 drumming sequences produced by 18 males, the beats occurred at nonrandom, regular intervals, yet individual males differed significantly in the shape parameters describing the distribution of their beat patterns, indicating individual drumming styles. Autocorrelation analyses of the longest drumming sequences further showed that they were highly regular and predictable like human music. These discoveries provide a rare comparative perspective on the evolution of rhythmicity and instrumental music in our own species, and show that a preference for a regular beat can have other origins before being co-opted into group-based music and dance.

Feather mites of the genera Dubininia and Cacatualges (Acari: Xolalgidae) associated with parrots (Aves: Psittaciformes) of the Old World.

This paper gives a systematic revision of feather mites of the genera Dubininia Vassilev, 1958 and Cacatualges Dabert, Badek and Skoracki, 2007 (Xolalgidae: Ingrassiinae) associated with parrots (Aves: Psittaciformes) of the Old World. Five new species are described: Cacatualges probosciger sp. n. from Probosciger aterrimus (Gmelin) (Cacatuidae) from New Guinea, Dubininia charmosynae sp. n. from Charmosyna pulchella Gray GR (Psittaculidae) from New Guinea, D. micropsittae sp. n. from Micropsitta pusio pusio (Scaltter) (Psittaculidae) from New Guinea, D. nestori sp. n. from Nestor notabilis Gould (Strigopidae) from New Zealand, and D. pezopori sp. n. from Pezoporus wallicus (Kerr) (Psittaculidae) from Tasmania, Australia. Four previously described species of Dubininia are redescribed based on material from type hosts: D. curta (Trouessart, 1885) from Platycercus elegans (Gmelin) (Psittaculidae), D. lorina (Trouessart, 1885) from Lorius domicella (Linnaeus) (Psittaculidae), D. melopsittaci Atyeo and Gaud, 1987 from Melopsittacus undulatus (Shaw) (Psittaculidae), and D. psittacina (Trouessart, 1885) from Strigops harboptilus Gray GR (Strigopidae) from New Zealand. A new diagnosis for the genus Dubininia is provided. A key to all presently known Dubininia species is provided for the first time.

Vocal individuality, but not stability, in wild palm cockatoos (Probosciger aterrimus)

The ability to identify individuals within a population is often essential for a detailed understanding of the ecology and conservation of a species. However, some species, including large parrots, are notoriously difficult to catch and mark for individual identification. Palm cockatoos (Probosciger aterrimus) are a large, poorly understood species of parrot which are likely in severe decline within the eastern part – and possibly the western part – of their range on Cape York Peninsula, Australia. Here, we investigated whether three different palm cockatoo call types are sufficiently individually distinctive to function as a non-invasive “marker” for identifying individuals over time. Using Discriminant Function Analysis, overall identification accuracy among 12 putative individuals for all call types was 81% (i.e. 148 out of 183 calls were assigned to the correct individual) on the basis of multiple temporal, energy (amplitude) and frequency measurements on the spectrogram. For three different call types, individual identification accuracy among males and females ranged from 69 to 95%. However, based on a limited sample sizes of five putative individuals between years, our data suggest that individual call structure, as quantified by call parameters, was not stable between years. We discuss the applicability of these results for future studies of palm cockatoos and other parrot species.

Geographic variation in the vocalizations of Australian palm cockatoos (Probosciger aterrimus)

Vocal dialects have been well studied in songbirds, but there have been fewer examples from parrots. The Australian population of palm cockatoos (Probosciger aterrimus aterrimus) from Cape York Peninsula in far north Queensland has an unusually large vocal repertoire for a parrot. Most calls are made during their unique display ritual, which also includes a variety of postures, gestures and the use of a manufactured sound tool. Here, we quantify the geographic structural variation of contact calls within and between six major populations of palm cockatoos in Australia, as well as the extent to which frequently given call types are shared. We found that palm cockatoos from the east coast (Iron Range National Park) possess unique contact calls and have fewer call types in common with other locations. This may have resulted from their long-term isolation in rainforest habitat refugia. Such variety in vocal traits presents a rare opportunity to investigate the evolutionary forces creating behavioural diversity in wild parrots. This is also a step towards assessing links between behavioural variation and population connectivity, which is important information for determining the conservation status of palm cockatoos.

The genome sequence of parrot bornavirus 5.

Although several new avian bornaviruses have recently been described, information on their evolution, virulence, and sequence are often limited. Here we report the complete genome sequence of parrot bornavirus 5 (PaBV-5) isolated from a case of proventricular dilatation disease in a Palm cockatoo (Probosciger aterrimus). The complete genome consists of 8842 nucleotides with distinct 5' and 3' end sequences. This virus shares nucleotide sequence identities of 69-74 % with other bornaviruses in the genomic regions excluding the 5' and 3' terminal sequences. Phylogenetic analysis based on the genomic regions demonstrated this new isolate is an isolated branch within the clade that includes the aquatic bird bornaviruses and the passerine bornaviruses. Based on phylogenetic analyses and its low nucleotide sequence identities with other bornavirus, we support the proposal that PaBV-5 be assigned to a new bornavirus species:- Psittaciform 2 bornavirus.

Vocal complexity in the palm cockatoo (Probosciger aterrimus)

Parrots are renowned for their capacity for vocal learning and production of diverse sounds in captivity, yet little is known about why such advanced vocal capabilities have evolved. Here, we provide a detailed description and statistical classification of the vocal repertoire of wild palm cockatoos Probosciger aterrimus and investigate the behavioural contexts of vocalizations. We show that palm cockatoos produce vocalizations that conform to most of the common vocalizations described for wild parrots, but also produce a variety of additional syllables in a phonological syntactic manner in the contexts of display and vocal-exchange with neighbouring individuals. These additional syllables are mainly produced by males and are often combined to form long, complex sequences. Unlike most parrots, palm cockatoos defend large multipurpose territories and we speculate that the large vocal repertoire and vocal assemblages of palm cockatoos may function in territorial defense.

Unrewarded Object Combinations in Captive Parrots.

In primates, complex object combinations during play are often regarded as precursors of functional behavior. Here we investigate combinatory behaviors during unrewarded object manipulation in seven parrot species, including kea, African grey parrots and Goffin cockatoos, three species previously used as model species for technical problem solving. We further examine a habitually tool using species, the black palm cockatoo. Moreover, we incorporate three neotropical species, the yellow- and the black-billed Amazon and the burrowing parakeet. Paralleling previous studies on primates and corvids, free object-object combinations and complex object-substrate combinations such as inserting objects into tubes/holes or stacking rings onto poles prevailed in the species previously linked to advanced physical cognition and tool use. In addition, free object-object combinations were intrinsically structured in Goffin cockatoos and in kea.

Subspecies identification with mtDNA and morphometrics in captive palm cockatoos, Probosciger aterrimus

The European breeding programme (EEP) for palm cockatoos Probosciger aterrimus has managed two subspecies, P. a. goliath and P. a. aterrimus , separately since it was found that only these two subspecies were distinct genetic lineages. Until recently a captive palm cockatoo was assigned to one or the other subspecies relying solely on morphology, P. a. goliath being reputedly larger than P. a. aterrimus . This study aimed at first to determine the subspecies of 78 captive palm cockatoos – mainly members of the EEP population – by sequencing a mitochondrial marker which had proved relevant for wild specimens. We also collected several anatomical measurements in order to compare the morphology with the molecular marker and to assess the presumed link between morphology and subspecies. Ten different haplotypes were found over 54 non-related samples, which could be arranged into two groups consistent with the subspecies P. a. goliath and P. a. aterrimus . Morphometric analyses revealed significant differences between the two subspecies, although there was some overlap between values for P. a. goliath and P. a. aterrimus . A stepwise discriminant analysis, which included one criterion for females and two criteria for males, allowed a correct assignation of 95% on average for our sample. These results allowed us to confirm that the captive population of palm cockatoos consists of two distinct genetic subgroups, which overall match with morphotypes. Therefore to preserve these two different conservation units we advise that P. a. goliath and P. a. aterrimus continue to be managed as two separate breeding populations. Morphology using a recommended set of measurements gives a fairly reliable insight into the subspecies identity for a newly introduced palm cockatoo, but testing mtDNA is highly recommended to confirm the correct subspecies determination.

The evolutionary history of cockatoos (Aves: Psittaciformes: Cacatuidae)

Cockatoos are the distinctive family Cacatuidae, a major lineage of the order of parrots (Psittaciformes) and distributed throughout the Australasian region of the world. However, the evolutionary history of cockatoos is not well understood. We investigated the phylogeny of cockatoos based on three mitochondrial and three nuclear DNA genes obtained from 16 of 21 species of Cacatuidae. In addition, five novel mitochondrial genomes were used to estimate time of divergence and our estimates indicate Cacatuidae diverged from Psittacidae approximately 40.7million years ago (95% CI 51.6–30.3Ma) during the Eocene. Our data shows Cacatuidae began to diversify approximately 27.9Ma (95% CI 38.1–18.3Ma) during the Oligocene. The early to middle Miocene (20–10Ma) was a significant period in the evolution of modern Australian environments and vegetation, in which a transformation from mainly mesic to xeric habitats (e.g., fire-adapted sclerophyll vegetation and grasslands) occurred. We hypothesize that this environmental transformation was a driving force behind the diversification of cockatoos. A detailed multi-locus molecular phylogeny enabled us to resolve the phylogenetic placements of the Palm Cockatoo (Probosciger aterrimus), Galah (Eolophus roseicapillus), Gang-gang Cockatoo (Callocephalon fimbriatum) and Cockatiel (Nymphicus hollandicus), which have historically been difficult to place within Cacatuidae. When the molecular evidence is analysed in concert with morphology, it is clear that many of the cockatoo species’ diagnostic phenotypic traits such as plumage colour, body size, wing shape and bill morphology have evolved in parallel or convergently across lineages.

Do Palm Cockatoos (Probosciger aterrimus) have long enough lifespans to support their low reproductive success?

As an order, Parrots (Psittaciformes) are both the longest lived birds and among the most endangered. Palm Cockatoos (Probosciger aterrimus) have an extremely slow life history, including one of the lowest rates of breeding success reported for parrots. Here we use population viability analysis (PVA) to examine whether populations of Palm Cockatoos are viable in the long term with such low rates of reproduction. We built PVA models for two field sites with robust data on reproductive success and availability of nest-hollows: Iron Range on Cape York Peninsula (Queensland, Australia) and Crater Mountain (Eastern Highlands Province, Papua New Guinea). Our Iron Range models incorporate a fluctuating resource base of nest-hollows resulting from natural losses from fire, wind and tree decay and natural replenishment through tree breakages in tropical cyclones. The number of females allowed to breed each year in the simulations was limited by the availability of hollows. Our Iron Range models suggest that the population is only viable if juvenile and adult mortality rates are very low, and that at least some birds in the population live to 100 years old. Based on known maximum lifespans in the Cacatuidae, we conclude that Palm Cockatoos at Iron Range are unlikely to live for long enough on average to support their low rates of reproduction, and highlight the possibility that the population may be in decline. At Crater Mountain, where nestlings are harvested for food by local people, the models suggest that the reported current rate of 40% of nestlings taken is not sustainable.