Orange-bellied Parrot Research Articles

Effects of age and captivity on the social structure and migration survival of a critically endangered bird

AbstractReintroductions of threatened species is a conservation strategy utilised around the world. Unfortunately, many translocated individuals have poor rates of survival post‐release. If released individuals are unable to socially integrate into wild populations, they might lose the safety of the group or fail to learn critical skills. We examined the effects of age and captivity on sociality and migration survival for the critically endangered orange‐bellied parrot (Neophema chrysogaster). As part of recovery efforts, adult birds are released in spring to contribute to breeding and juveniles are released in autumn prior to migration. Historically, captive‐bred adults have low rates of migration survival, whereas captive and wild juveniles survive at comparable rates. We investigated both the long‐term impacts of captivity on sociality and how sociality impacted migration survival by constructing social networks and comparing captive and wild birds of different age classes. We found no differences between captive and wild birds, suggesting that released birds integrated into the population. However, juveniles were more strongly connected and demonstrated greater network stability than adults. While we found no impact of sociality on survival, our results provide evidence of different migration strategies previously described for juveniles and adults: adults depart in small groups and juveniles depart as a larger flock a few weeks later. We suggest that the low migration survival of captive‐bred adults may be attributable to this cohort missing the juvenile flocking phase. These results suggest that a juvenile developmental phase may be impactful in this species for future survival.

Virome of Australia's most endangered parrot in captivity evidenced of harboring hitherto unknown viruses.

The impact of circulating viruses on the critically endangered, orange-bellied parrot (OBP) population can be devastating. The OBP already faces numerous threats to its survival in the wild, including habitat loss, predation, and small population impacts. Conservation of the wild OBP population is heavily reliant on supplementation using OBPs from a managed captive breeding program. These birds may act as a source for introduction of a novel disease agent to the wild population that may affect survival and reproduction. It is, therefore, essential to monitor and assess the health of OBPs and take appropriate measures to prevent and control the spread of viral infections. This requires knowledge of the existing virome to identify novel and emerging viruses and support development of appropriate measures to manage associated risk. By monitoring and protecting these animals from emerging viral diseases, we can help ensure their ongoing survival and preserve the biodiversity of our planet.

A record of the parasitic mite Hemimyialges macdonaldi (Evans et al. 1963) (Acari: Epidermoptidae) in the Orange-bellied Parrot Neophema chrysogaster (Latham, 1790) (Psittaciformes: Psittaculidae) in Australia.

The subcutaneous parasitic mite Hemimyialges macdonaldi was found in a specimen of the Orange-bellied Parrot Neophema chrysogaster that died in captivity. A review of the host range and geographic distribution of this mite shows it is cosmopolitan and occurs in a very wide range of birds. It does not appear to be a cause of significant mortality in its hosts.

Orange-bellied parrots

Dejan Stojanovic and Robert Heinsohn introduce the Critically Endangered orange-bellied parrot from Australia.

Carry‐over effects of nestling physical condition predict first‐year survival of a critically endangered migratory parrot

AbstractConservation breeding programs are an increasingly important tool to help supplement declining wild populations, but captive‐bred animals generally do not survive well post‐release. Early life in captivity has the potential to influence growth and development, with impacts carrying over to affect survival. Understanding carry‐over effects of captivity and consequences on survival is critically important for conservation efforts globally but remains poorly understood. We examined the relationship between early‐life environment, physical condition, and juvenile survival of wild and captive‐bred critically endangered orange‐bellied parrots (Neophema chrysogaster). Using nestling growth models, we calculated a body condition index for 1,039 wild and captive‐bred orange‐bellied parrots hatched over six breeding seasons. Nestling body condition varied with year, provenance, and brood position. Wild nestlings had consistently higher body condition than captive‐bred nestlings, and first‐hatched nestlings were typically heavier than later hatched siblings. We then investigated first‐year survival for 298 wild‐born and captive‐bred released parrots in the wild. Overall, first‐year survival was 27.5%, and individual body condition was more influential than provenance in predicting survival. Our findings could be used to aid the selection of individuals for release that have the best prospects of surviving in the wild. This study addresses important questions about the post‐release fitness of captive‐bred animals, and our metric of assessing physical condition provides a straightforward tool for other conservation breeding programs to adapt management techniques to improve survival outcomes.

Identifying factors affecting captive breeding success in a critically endangered species

ABSTRACT Captive breeding programs are an increasingly important tool for species’ conservation efforts, but not all species reproduce well in captivity. Identifying factors that affect the reproductive success of captive populations is crucial to improving the performance and management of conservation-breeding programs, both by providing individuals for release and informing decision making. We examined breeding records collected from the long-running conservation-breeding program for the critically endangered Orange-bellied Parrot Neophema chrysogaster over an 11-year period. We examined egg hatching rate, nestling survival rate, and offspring sex ratio in response to a wide range of variables related to characteristics of individual birds, breeding events, and the captive environment. The hatch rate of eggs was higher in first clutches compared to second clutches and was lower than the wild population. The survival rate of nestlings through to fledging was variable between years but became higher and more consistent over the last five years of the study period. Variation in brood sex ratio was not related to any of the potential explanatory variables that we examined. This is one of the first studies to examine reproductive data in a long-running conservation-breeding program and shows that many common metrics do not explain reproductive variation. Our approach provides a framework for managers to investigate factors affecting reproductive success in conservation breeding programs more broadly.

Conservation management in the context of unidentified and unmitigated threatening processes

The decision to intervene in endangered species management is often complicated. Migratory species exemplify this difficulty because they experience diverse threats at different times and places that can act cumulatively and synergistically on their populations. We use population viability analysis (PVA) to compare potential conservation interventions on the critically endangered, migratory Orange-bellied Parrot Neophema chrysogaster. This species suffers high juvenile mortality, but it is not clear why this is so. Given uncertainty about the best recovery strategy, we compare PVA scenarios that simulate various ways of utilizing captive-bred parrots to support the wild population in the context of unresolved threatening processes. Increasing the number of juveniles entering the population each year had the greatest benefit for population growth rate and size. Directly lowering juvenile mortality rates is difficult given uncertainty about the drivers of mortality in the wild. In lieu of this, releasing 100 juveniles from captivity to the wild population each autumn (either as a stand-alone action, or in combination with other interventions) was the most feasible and straightforward intervention of the options we tested. However, our PVAs also show that unless substantial and sustainable reductions can be made to juvenile mortality rates, Orange-bellied Parrots will remain dependent on intensive conservation management. This study highlights the utility of PVAs for answering practical questions about how to implement species conservation. PVAs provide a way to incorporate the best available information in a replicable modelling framework, and to identify impacts of parameter uncertainty on demographic trends.

An ecological risk assessment for the impacts of offshore wind farms on birds in Australia

AbstractAn ecological risk assessment, based on life‐history and behavioural attributes of 273 bird taxa, was used to identify which of those taxa are at high risk from negative interactions with offshore wind farms in Australia. The marine area of Australia was divided by state/territory boundaries perpendicular to the coast into eight regions, with Western Australia further divided into north and south, and a Bass Strait region bounded by the Victoria coast and the north coast of Tasmania. These regions were subdivided into coastal, inshore and offshore sub‐regions and a risk summary for all bird taxa occurring in each of these sub‐regions produced. In coastal and inshore sub‐regions of Bass Strait, South Australia and Tasmania, the species with the highest risk scores were Orange‐bellied Parrot Neophema chrysogaster, Furneaux White‐fronted Tern Sterna striata incerta, Swift Parrot Lathamus discolor, Shy Albatross Thalassarche cauta, Far Eastern Curlew Numenius madagascariensis and Anadyr Bar‐tailed Godwit Limosa lapponica anadyrensis. In offshore sub‐regions in southern Australia, the highest risk species were all albatrosses, comprising Northern Royal Diomedea sanfordi, Eastern Antipodean D. antipodensis antipodensis, Gibson's D. antipodensis gibsoni, Wandering D. exulans, Amsterdam D. amsterdamensis and Grey‐headed Albatross T. chrysostoma. Compared to onshore installations, there are logistical challenges to quantifying the potential and realized impacts of offshore wind farms that require different approaches to data collection and analyses. The extensive development of offshore wind farms in the Northern Hemisphere provides examples of best and emerging approaches to quantify and mitigate negative impacts of offshore wind farms that can be applied in an Australian context. Despite differences in the species involved, the same approaches to identifying high‐risk species and to the monitoring and mitigation of negative impacts should be applied in a coordinated, regional‐scale approach to the development of offshore wind farms in Australia.

Can we save Australia’s endangered wildlife by increasing species recognition?

Australia’s species extinction rate is one of the highest in the world. Yet, there is limited evidence regarding people’s recognition of, and preferences and support for, Australian endangered wildlife. This paper presents survey responses from 223 Zoos Victoria visitors (response rate: 39.1 %) and 90 community members (Victoria, Australia). We examined people’s top 10 overall (global) and Australian favourite animals, and conducted an in-depth exploration of recognition of, and preferences and support for, seven Australian endangered species identified as being at risk of extinction within the next decade, including: the leadbeater’s possum (Gymnobelideus leadbeateri), eastern barred bandicoot (Perameles gunnii), helmeted honeyeater (Lichenostomus melanops cassidix), southern corroboree frog (Pseudophryne corroboree), Lord Howe Island (LHI) stick insect (Dryococelus australis), Tasmanian devil (Sarcophilus harrisii), and the orange-bellied parrot (Neophema chrysogaster). Results indicate that the only Australian animals to feature in the overall top 10 favourite list were the kangaroo (ranked 9th for both sample groups) and koala (ranked 6th and 10th for the community and zoo sample, respectively). The Tasmanian devil had the highest rate of recognition (>86 %), in comparison to the remaining six species (1.2–7.3 % across both samples). Endangered species were not prominent in the top favourite Australian species. Australian endangered species’ likeability ratings typically followed the pattern of mammals being most likeable (Tasmanian devil and leadbeater’s possum), followed by birds, frogs, and insects (helmeted honeyeater, southern corroboree frog, and LHI stick insect). Importantly, for most endangered native species featured (4/7 and 6/7; zoo and community, respectively), simply being able to recognise species significantly (p <.05) increased people’s willingness to support their conservation. Findings underscore several powerful opportunities for future conservation programs to contribute to Australian endangered species conservation by striving to increase public familiarity with Australian species most at risk of extinction.

Metagenomic detection and characterisation of multiple viruses in apparently healthy Australian Neophema birds

Emerging viral pathogens are a significant concern, with potential consequences for human, animal and environmental health. Over the past several decades, many novel viruses have been found in animals, including birds, and often pose a significant threat to vulnerable species. However, despite enormous interest in virus research, little is known about virus communities (viromes) in Australian Neophema birds. Therefore, this study was designed to characterise the viromes of Neophema birds and track the evolutionary relationships of recently emerging psittacine siadenovirus F (PsSiAdV-F) circulating in the critically endangered, orange-bellied parrot (OBP, Neophema chrysogaster), using a viral metagenomic approach. This study identified 16 viruses belonging to the families Adenoviridae, Circoviridae, Endornaviridae, Picobirnaviridae and Picornaviridae. In addition, this study demonstrated a potential evolutionary relationship of a PsSiAdV-F sequenced previously from the critically endangered OBP. Strikingly, five adenoviral contigs identified in this study show the highest identities with human adenovirus 2 and human mastadenovirus C. This highlights an important and unexpected aspects of the avian virome and warrants further studies dedicated to this subject. Finally, the findings of this study emphasise the importance of testing birds used for trade or in experimental settings for potential pathogens to prevent the spread of infections.

Genomic Characterisation of a Highly Divergent Siadenovirus (Psittacine Siadenovirus F) from the Critically Endangered Orange-Bellied Parrot (Neophema chrysogaster).

Siadenoviruses have been detected in wild and captive birds worldwide. Only nine siadenoviruses have been fully sequenced; however, partial sequences for 30 others, many of these from wild Australian birds, are also described. Some siadenoviruses, e.g., the turkey siadenovirus A, can cause disease; however, most cause subclinical infections. An example of a siadenovirus causing predominately subclinical infections is psittacine siadenovirus 2, proposed name psittacine siadenovirus F (PsSiAdV-F), which is enzootic in the captive breeding population of the critically endangered orange-bellied parrot (OBP, Neophema chrysogaster). Here, we have fully characterised PsSiAdV-F from an OBP. The PsSiAdV-F genome is 25,392 bp in length and contained 25 putative genes. The genome architecture of PsSiAdV-F exhibited characteristics similar to members within the genus Siadenovirus; however, the novel PsSiAdV-F genome was highly divergent, showing highest and lowest sequence similarity to skua siadenovirus A (57.1%) and psittacine siadenovirus D (31.1%), respectively. Subsequent phylogenetic analyses of the novel PsSiAdV-F genome positioned the virus into a phylogenetically distinct sub-clade with all other siadenoviruses and did not show any obvious close evolutionary relationship. Importantly, the resulted tress continually demonstrated that novel PsSiAdV-F evolved prior to all known members except the frog siadenovirus A in the evolution and possibly the ancestor of the avian siadenoviruses. To date, PsSiAdV-F has not been detected in wild parrots, so further studies screening PsSiAdV-F in wild Australian parrots and generating whole genome sequences of siadenoviruses of Australian native passerine species is recommended to fill the siadenovirus evolutionary gaps.

Using phylogenetics to explore interspecies genetic rescue options for a critically endangered parrot

AbstractAs the global biodiversity crisis deepens, with increasing habitat fragmentation and a changing climate, innovative options for conserving species are being explored. One such conservation action is genetic rescue: introduction of new alleles to promote population fitness. However, for critically endangered species where only one viable population remains, options for introducing new alleles are limited. Interspecies hybridization offers a potential solution but requires resolution of evolutionary relationships, a sound understanding of species biology, social license, and permissive legislative frameworks. Here, we show how phylogenetics and species biology can inform genetic rescue options for the orange‐bellied parrot (OBP;Neophema chrysogaster), a critically endangered Australian bird with one small remaining wild population. Our phylogenetic analysis of mitochondrial genomes and nuclear loci for all congeneric species provided strong support for OBPs being the sister species to a group comprising elegant, rock, and blue‐winged parrots. Accounting for species distribution, behavior, and ecology, a captive trial of interspecific hybridization with the blue‐winged parrot is recommended, including assessment of the fitness of hybrid individuals. Introduction of new alleles into the OBP genome would achieve the conservation goal of improving genetic diversity in a critically endangered species. Concurrently, legislative issues will need to be resolved.

Differences in wing shape of captive, critically endangered, migratory Orange-bellied Parrot Neophema chrysogaster relative to wild conspecifics

ABSTRACT Living in a captive environment may compromise phenotypic traits critical to survival in the wild. Captive animals that differ from the ideal wild phenotype may have impaired fitness after release, especially if there is extreme phenotypic selection during some life history stages. Wing shape of migratory birds is crucial to migration efficiency, and changes to wing shape in captivity may severely affect survival after release. We investigate wing shape of migratory Orange-bellied Parrots Neophema chrysogaster in captivity and the wild. The first two flight feathers were shorter in captive birds, and the fifth and sixth feathers were longer than wild conspecifics. These differences altered wing shape, producing a more proximal tip and a more convex trailing edge than the wild phenotype, which likely alters flight performance. This wing shape contravenes expectations from general patterns of wing shape in migratory birds. Wing shape in the captive birds sampled was independent of inbreeding, generations in captivity and ancestry. Captive environments may affect feather development or impose some selective pressure on wing shape. Alternatively, release from intense phenotypic selection during migration may allow parrots with wing shapes poorly adapted to migration to survive and breed in captivity. Altered wing shape may contribute to low observed survival of parrots released to the wild.

REPEAT SPILLOVER OF BEAK AND FEATHER DISEASE VIRUS INTO AN ENDANGERED PARROT HIGHLIGHTS THE RISK ASSOCIATED WITH ENDEMIC PATHOGEN LOSS IN ENDANGERED SPECIES.

Conservation efforts for the orange-bellied parrot (Neophema chrysogaster), one of the world's most critically endangered bird species, have been hampered by beak and feather disease virus (BFDV) spillover infection. To understand the vulnerability of orange-bellied parrots to potential reservoirs of infection we investigated geographic versus taxonomic structure in 160 full-genome and 319 partial Rep gene BFDV sequences from captive and wild orange-bellied parrots and other wild parrot species in Australia. We found that Australian BFDV populations are structured by host taxonomy. By identifying genetic stratification of BFDV in reservoir hosts we characterized three separate recent incursions of BFDV into orange-bellied parrots from other wild parrots, which demonstrates the susceptibility of critically endangered species to multiple threats of pathogen re-emergence. Our study highlighted how loss of endemic circulating BFDV in orange-bellied parrots precipitated repeated spillover into an immunologically naïve population, causing significant disease.

Evaluation of intervention aimed at improving reproductive success in Orange‐bellied Parrots Neophema chrysogaster: Lessons, barriers and successes

SummaryAssessing feasibility and identifying constraints that affect project implementation is a crucial step for planning long‐term species recovery actions for field‐based programs. We report on the outcomes of a conservation intervention on the most endangered parrot in the world, the Orange‐bellied Parrot (Neophema chrysogaster). We aimed to trial new techniques to increase reproductive success of wild nests and address key knowledge gaps. We aimed to achieve higher reproductive success using (i) intervention – where fertile eggs or nestlings would be fostered from captivity to wild nests that suffered infertility or had small brood sizes and (ii) rescue – where wild‐born nestlings would be removed from nests if they were ailing and either fostered to another nest or hand reared to improve their survival. Our project provided proof of principle that it is possible to implement intensive, individual‐level monitoring and intervention (via fostering of nestlings to infertile nests) to address reproductive problems for the Orange‐bellied Parrot. However, we also found important factors that hindered our ability to achieve project aims (management of biosecurity), and identified unexpected factors that have important implications for future application of these techniques (nest abandonment from video camera deployment, rapid death of unhealthy nestlings hindering rescue attempts). Our project tested techniques and tools to provide new approaches for fighting extinction of the Orange‐bellied Parrot, and yielded important new information about the species ecology and management options.

Short‐term impacts of prescribed burning on Orange‐bellied Parrot (Neophema chrysogaster) food plant abundance

SummaryFire has important implications for the availability of suitable types of habitat for animals. Different species vary in their responses to fire, and quantifying the responses of key habitat attributes may facilitate manipulation of fire regimes to improve conditions for species of conservation concern. The Orange‐bellied Parrot Neophema chrysogaster prefers recently burned habitat for foraging when breeding but knowledge of how fire affects this species and its habitat is limited. We implemented a 2‐year before‐after‐control‐impact (BACI) study to quantify short‐term impacts of fire on food plants and habitat features. Relative to control sites, the four food plants we monitored in the treatment area responded differently to fire: one did not recover, two reached pre‐burn abundance after 20 months and another recovered by 1 year after fire, and by 20 months was more common in treatment sites. Relative to controls, the proportion of bare earth at treatment sites increased after fire and then gradually declined, while mean vegetation height at treatment plots declined after fire and then gradually increased. Twenty months after fire, parrots foraged on abundant regeneration of the Dwarf Everlasting (Helichrysum pumilum) and fed the seeds of this species to their nestlings. Fire alters the availability of key resources needed by breeding Orange‐bellied Parrots, and ongoing manipulation of fire regimes may relieve limitation of natural foods for this species.

Genetic impacts of conservation management actions in a critically endangered parrot species

Establishing populations of endangered species in captivity is becoming an increasingly common component of species recovery programs for insurance against extinction, and/or for reintroductions. It is important for the success of these efforts that captive populations are genetically representative of wild source populations, and that genetic diversity is maintained over time. Our study presents SNP data from wild and captive populations of the critically endangered Australian orange-bellied parrot (Neophema chrysogaster). We examine the genetic effects of a decision made in the 2010/2011 breeding season to recruit half of the juvenile cohort (n = 21), from a wild population in decline, to supplement an existing captive program. We report that heterozygosity among wild birds decreased in the years after this action. Following multiple releases of captive-reared birds back into the wild (occurring annually since 2013), captive and wild populations have attained similar overall levels of heterozygosity, and genetic differentiation between these populations is low. Parentage analyses confirm that captive-bred released individuals have successfully paired with wild birds and produced offspring. Our study suggests that translocation of wild individuals into captivity, from wild populations in decline, can potentially have deleterious lasting impacts on genetic diversity levels in these populations. However, our data also confirm that in captivity, founder diversity can be successfully preserved over time, and addition of wild founders can improve captive population health. The genetic diversity retained in captive populations can also be reintroduced to wild populations at a later date, provided that captive-release individuals are able to reproductively contribute to their recipient population.

Spatial bias in implementation of recovery actions has not improved survival of Orange-bellied Parrots Neophema chrysogaster

ABSTRACT Not all conservation interventions are successful at correcting threatening processes and the odds of failure increase with uncertainty concerning the true threats to a population. Failure of conservation actions to improve demographic rates might be evidence of their ineffectiveness, or that other unaddressed threats nullify the potential benefits of interventions. Knowledge of key threatening processes that afflict Orange-bellied Parrots Neophema chrysogaster is lacking, but population modelling predicts that actions in the breeding range are unlikely to correct decline unless mortality during migration/wintering is addressed. Despite this, there has been a spatial bias in recovery effort towards the breeding range in recent decades. We model annual survival data spanning 1995–2017 for the last known wild population to evaluate whether the predictions about the efficacy of recovery efforts are accurate. Based on our best-supported model, probability of adult survival was constant at 0.58, but juvenile survival declined from 0.51 to 0.20. Survival did not improve when we considered the effects of recovery actions in the breeding grounds (which only aimed to correct local scale threats anyway). This result supports predictions that conservation interventions in the breeding ground alone are not sufficient to recover this species. We conclude that although interventions in the breeding ground may have corrected local threats, birds succumbed to other threats during migration/winter. It is crucial that new targeted interventions be identified and implemented to reduce mortality of Orange-bellied Parrots in their migration/winter habitats to prevent extinction.

Nestling growth and body condition of critically endangered Orange-bellied Parrots Neophema chrysogaster

ABSTRACT Intervening when bird nestlings are performing poorly relative to the population mean may be a management priority if individuals are of high-conservation value. Assessing body condition may enable identification of potential problems before they cause mortality. We aimed to provide a tool for conservation managers to identify underperforming nestlings in a severely threatened bird population. We develop models of nestling growth and empirically quantify nestling body condition of critically endangered Orange-bellied Parrots Neophema chrysogaster, which have declined to only a single population in southwestern Tasmania, Australia. Using census data on growth of nestlings born over four years into the contemporary wild population, we test whether a body condition index is influenced by sex, hatch order, year of birth, brood size, whether one or both parents were captive bred, and fledging date. The best model describing body condition in Orange-bellied Parrot nestlings included additive effects of year of birth and hatch order. Nestling body condition was lowest in 2013, where first hatched nestlings were 2.5 g lighter than those born in 2016, and > 4.2 g lighter than in 2017/18. Nestlings that hatched either first or in the middle of the brood were respectively 4.8 g and 3.8 g heavier than last-hatched birds. Our body condition index provides a repeatable, rapid and cheap way to assess body condition of wild Orange-bellied Parrot nestlings. This represents a step towards accurate evaluation of management actions aimed at improving reproductive outcomes for this species, and provides a framework for developing hypotheses to test using an empirical and measurable index of individual quality.

Low innate immune-gene diversity in the critically endangered orange-bellied parrot (Neophema chrysogaster)

ABSTRACTOutbreaks of disease in threatened species can increase the likelihood of extinction by reducing population size. Low immunogenetic diversity can increase susceptibility to, and severity of, disease outbreaks. Our study measured genetic diversity at innate immune genes the Toll-like receptors (TLRs) in a critically endangered Australian bird, the orange-bellied parrot (Neophema chrysogaster). Conservation of this species has recently been challenged by several disease outbreaks. We found low diversity at six TLR genes in both captive and wild orange-bellied parrot populations, similar to results seen in other threatened bird species. Three loci were found to be monomorphic across all samples, including birds which were recorded to have been involved in recent disease events. Phylogenetic analysis of TLR sequences from Neophema chrysogaster as well as representatives of all other species within parrot genera Neophema and Neopsephotus revealed a small number of sites under pervasive and/or episodic positive selection, and a number of sites under negative selection. This study is the first to investigate functional genetic diversity in the orange-bellied parrot.