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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,...

Assessing 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.

This project was funded primarily by grants to F.A from BirdLife Australia (Professor Allen Keast Research Award); The Holsworth Wildlife Research Endowment & the Ecological Society of Australia; the Mohamed bin Zayed Species Conservation Fund [172516602], with additional support from the Australian National University Research School of Biology, and 1156 people that contributed to our crowd funding campaign ’Parrots, the pardalote and the possum’. D.S. received support from the Australian Government’s National Environmental Science Program through the Threatened Species Recovery Hub. The work was undertaken under an Australian National University Animal Ethics Permit A2017/38 and a Tasmanian Government Scientific Permit TFA18255.

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...

Indonesia has been identified as the highest priority country for parrot conservation based on the number of species, endemics, and threats (trapping and smuggling). It is crucial to understand the current population status of parrots in the wild in relation to the illegal wildlife trade but the ecology and population dynamics of most parrot species in this region remain poorly understood. We conducted a parrot survey around an area of high biodiversity in the Manusela National Park, in Seram Island, Indonesia. We used a combination of fixed-radius point counts and fixed-width line transects to count multiple species of parrots. We recorded nearly 530 wild parrots from 10 species in and around Manusela National Park. The dominant parrot species were Eos bornea, Trichoglosus haematodus, and Geoffroyus geoffroyi. We applied the Savage selectivity index to evaluate poaching of parrot species in proportion to their abundance and which species had higher than expected poaching pressure. This study has important implications for the conservation status of endemic parrots (Cacatua moluccensis, Lorius domicella, and Eos semilarvata) and shows that parrots in the Manusela NP are largely threatened by poaching.

Fear may elicit behavioural and physiological responses in animals. We conducted a pilot study aiming to reduce bird nest predation in Tasmania by the introduced Sugar Glider (Petaurus breviceps) by broadcasting calls of predatory owls. We designed a solar‐powered, automated weatherproof stereo for long‐term call broadcast in a forest environment. This device may have useful applications in other environments where long‐term call broadcast is required in remote field conditions. Call broadcast did not reduce the likelihood of Sugar Glider nest predation on either active bird nests or artificial nests baited with farmed quail eggs. If we elicited fear in Sugar Glider individuals with call broadcast, this fear did not result in behavioural changes that could be exploited to achieve the conservation objective of lower predation.

In captivity, novel selective pressures can lead to divergence from the wild source population, which can be a liability for animals released into the wild. Easily measured indices of change, like ...

Patterns of distribution and abundance of species are dependent on their particular ecological requirements. Taking specialisation into account is important for interpreting population parameters. Here, we evaluate population parameters of an endangered habitat specialist, the forty‐spotted pardalote (Pardalotus quadragintus; dependent on white gum Eucalyptus viminalis in south‐eastern Tasmania), and a sympatric congeneric habitat generalist, the striated pardalote (Pardalotus striatus). We used occupancy models to estimate occupancy of both species, and distance sampling models to estimate population density and size on North Bruny Island. Within their shared habitat (i.e. white gum forest), we also fitted hierarchical distance sampling models to estimate density in relation to fine‐scale habitat features. We show that forty‐spotted pardalotes only occurred in forests where white gums were present, with a mean density of 2.7 birds per hectare. The density of forty‐spotted pardalotes decreased in areas with abundant small trees and trees with dead crowns, but they increased in areas where larger white gums were abundant. The striated pardalote was widespread, but where white gums were present, they occurred at 2.1 birds per hectare, compared to 0.6 birds per hectare in forests where white gums were absent. Within white gum habitat, the relative abundance of forty‐spotted pardalotes and dead trees had a positive effect on the density of striated pardalotes while small trees had a negative effect. Our study reveals that although widespread, the generalist is most abundant in the limited areas of habitat suitable for the specialist, and this indicates the need of future research to look at whether this pattern of occurrence exacerbates competition in resource depleted habitats.

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.

Most species produce equal numbers of sons and daughters, and sex differences in survival after parental care do not usually affect this pattern. Temporary overproduction of the scarcer sex can be adaptive when generations overlap, the sexes differ in life-history expectations, and parents can anticipate future mating opportunities. However, an alternative strategy of maximizing the competitiveness of the more abundant sex in these circumstances remains unexplored. We develop theory showing how mothers can maximize reproductive value when future mate competition will be high by producing more sons in the advantageous early hatching positions within their broods. Our model for optimal birth order was supported by long-term data of offspring sex in a parrot facing catastrophic female mortality caused by introduced predators. Swift parrots ( Lathamus discolor ) suffer high female mortality due to introduced sugar gliders ( Petaurus breviceps ) creating fluctuating male-biased adult sex ratios. Offspring hatched early within broods fledged in better condition, and in support of our model were more likely to be male in years with higher adult female mortality. We found a highly significant rank-order correlation between observed and predicted birth sex ratios. Our study shows the potential for mothers to maximize reproductive value via strategic biases in offspring sex depending on the advantages conferred by birth order and the predictability of future mate competition. Our long-term data support the predictions and appear to suggest that sex allocation strategies may evolve surprisingly quickly when anthropogenic pressures on populations are severe.

Cultures in humans and other species are maintained through interactions among conspecifics. Declines in population density could be exacerbated by culture loss, thereby linking culture to conservation. We combined historical recordings, citizen science and breeding data to assess the impact of severe population decline on song culture, song complexity and individual fitness in critically endangered regent honeyeaters ( Anthochaera phrygia ). Song production in the remaining wild males varied dramatically, with 27% singing songs that differed from the regional cultural norm. Twelve per cent of males, occurring in areas of particularly low population density, completely failed to sing any species-specific songs and instead sang other species' songs. Atypical song production was associated with reduced individual fitness, as males singing atypical songs were less likely to pair or nest than males that sang the regional cultural norm. Songs of captive-bred birds differed from those of all wild birds. The complexity of regent honeyeater songs has also declined over recent decades. We therefore provide rare evidence that a severe decline in population density is associated with the loss of vocal culture in a wild animal, with concomitant fitness costs for remaining individuals. The loss of culture may be a precursor to extinction in declining populations that learn selected behaviours from conspecifics, and therefore provides a useful conservation indicator.

Sex-biased mortality can lead to altered adult sex ratios (ASRs), which may in turn lead to harassment and lower fitness of the rarer sex and changes in the mating system. Female critically endangered swift parrots (Lathamus discolor) suffer high predation while nesting due to an introduced mammalian predator, the sugar glider (Petaurus breviceps). High predation on females is causing severe population decline alongside strongly biased adult sex ratios (≥73% male). Our 6-year study showed that 50.5% of critically endangered swift parrot nests had shared paternity although the birds remained socially monogamous. Shared paternity increased significantly with the local rate of predation on breeding females, suggesting that rates of shared paternity increased when the ASR became more biased. Nests that were not predated produced fewer fledglings as the local ASR became more male-biased possibly due to higher interference during nesting from unpaired males. Population viability analyses showed that part of the predicted decline in the swift parrot population is due to reduced reproductive success when paternity is shared. The models predicted that the population would decline by 89.4% over three generations if the birds maintained the lowest observed rate of shared paternity. This compares with predicted population reductions of 92.1-94.9% under higher rates of shared paternity. We conclude that biases in the ASR, in this case caused by sex-specific predation from an introduced predator, can lead to changes in the mating system and negative impacts on both individual fitness and long-term population viability.

Interactive effects of habitat loss and interspecific competition are major threats to global biodiversity. Managing despotic competitors in modified landscapes is a conservation priority, but implementing actions to benefit rare and highly mobile species is challenging. In Australia, overabundance of hyperaggressive noisy miners following woodland fragmentation and degradation is a key threatening process given their impact on songbirds including the nomadic, critically endangered regent honeyeater. Recent studies have found rapid noisy miner recolonization following their experimental removal, questioning the efficacy of miner removal as a conservation measure. We estimated the relative habitat saturation of noisy miners at a hotspot of threatened bird diversity. We then experimentally removed 350 noisy miners and assessed the effect of this removal on subsequent noisy miner abundance, relative to a control area. We monitored the occurrence of noisy miners near regent honeyeater nests and modelled the effect of noisy miner removal on songbird populations. Noisy miner removal significantly decreased noisy miner abundance throughout the breeding season, when 15–18 regent honeyeaters nested in the miner removal area. Songbird abundance and species richness increased significantly in the miner removal area, relative to the control area. We provide a rare example of how spatially and temporally targeted preventative action can reduce threats for nomadic and highly threatened species during breeding and prevent ongoing avian diversity loss more broadly.

Funding was provided by 1,156 peoplethat contributed to our crowd funding campaign “Parrots,the pardalote and the possum,” the Australian Research Council (DP140104202), and the Australian Government National Environmental Science Program. WJS is funded by the Arcadia Fund.

Identifying factors influencing the demographics of threatened species is essential for conservation, but a lack of comprehensive demographic data often impedes the effective conservation of rare and mobile species. We monitored breeding of critically endangered and semi‐nomadic Regent Honeyeaters Anthochaera phrygia (global population c. 100 pairs) over 3 years throughout their range. Overall nest success probability (0.317) was highly spatially variable and considerably lower than previous estimates for this (and many other honeyeater) species, as was productivity of successful nests (mean 1.58 juveniles fledged). Nest surveillance revealed high predation rates by a range of birds and arboreal mammals as the primary cause of nest failure. An estimated 12% of pairs either failed to establish a territory or their nests did not reach the egg stage. We also found a male bias to the adult sex ratio, with an estimated 1.18 males per female. Juvenile survival for the first 2 weeks after fledging was high (86%). Management interventions that aim to increase nest success in areas of low nest survival must be investigated to address an apparent decline in reproductive output and avoid extinction of the Regent Honeyeater. We show that temporal and spatial variation in the breeding success of rare and highly mobile species can be quantified with robust population monitoring using sampling regimens that account for their life histories. Understanding the causes of spatio‐temporal variation in breeding success can enhance conservation outcomes for such species through spatially and temporally targeted recovery actions.

SUMMARYAspects of species life histories may increase their susceptibility to climate change. Owing to their exclusive reliance on environmental sources of heat for incubation, megapodes may be especially vulnerable. We employed a trait-based vulnerability assessment to weigh their exposure to projected climate variables of increasing temperatures, fluctuating rainfall and sea level rise and their biological sensitivity and capacity to adapt. While all 21 species were predicted to experience at least a 2 °C increase in mean annual temperature, 12 to experience a moderate or greater fluctuation in rainfall and 16 to experience rising seas, the most vulnerable megapodes are intrinsically rare and range restricted. Species that employ microbial decomposition for incubation may have an adaptive advantage over those that do not and may be more resilient to climate change. The moderate microclimate necessary for mound incubation, however, may in some areas be threatened by anthropogenic habitat loss exacerbated by warmer and seasonally drier conditions. As with many avian species, little is known about the capacity of megapodes to adapt to a changing climate. We therefore recommend that future research efforts investigate megapode fecundity, gene flow and genetic connectivity at the population level to better determine their adaptive capacity.

Mobile species pose major challenges for conservation because of their unpredictable, large scale movements in response to fluctuating resources. If locations with critical resources overlap with threats, large proportions of a mobile population may be exposed to threats. Critically endangered and nomadic swift parrots Lathamus discolor nest wherever food is most abundant in their breeding range, but concern exists that nest predation from an introduced predator may severely affect their population. Although swift parrots nest on predator-free offshore islands, population viability analysis indicates that is land nesting alone may be insufficient to offset extinction risk from high mainland predation rates assuming that the species is a single panmictic population. We test the assumption that swift parrots act as a single conservation unit. We undertook a population genetic analysis using seven microsatellite loci and samples obtained over 6 years from across the breeding range of swift parrots. We found no evidence of departure from Hardy–Weinberg expectations across the species and both Analysis of Molecular Variance and Bayesian Structure analyses failed to detect any evidence for genetic differentiation across the samples both spatially and temporally. These results, supported by simulations, indicate panmixia and a lack of population genetic structure in swift parrots. Unlike a sedentary or site philopatric species, the majority of the swift parrot population may be at risk of exposure to predation when unpredictable resources draw individuals away from islands. These findings support a key assumption of population viability models that predict an extreme reduction in population size for swift parrots, and address a major gap in knowledge of the species’ ecology. Our study has implications both for the development of effective conservation management strategies and for the longer-term evolution of avoidance of predator-infested habitat in swift parrots.

Parrots (Psittaciformes) are a well-studied, diverse group of birds distributed mainly in tropical and subtropical regions. Today, one-third of their species face extinction, mainly due to anthropogenic threats. Emerging tools in genetics have made major contributions to understanding basic and applied aspects of parrot biology in the wild and in captivity. In this review, we show how genetic methods have transformed the study of parrots by summarising important milestones in the advances of genetics and their implementations in research on parrots. We describe how genetics helped to further knowledge in specific research fields with a wide array of examples from the literature that address the conservation significance of (1) deeper phylogeny and historical biogeography; (2) species- and genus-level systematics and taxonomy; (3) conservation genetics and genomics; (4) behavioural ecology; (5) molecular ecology and landscape genetics; and (6) museomics and historical DNA. Finally, we highlight knowledge gaps to inform future genomic research on parrots. Our review shows that the application of genetic techniques to the study of parrot biology has far-reaching implications for addressing diverse research aims in a highly threatened and charismatic clade of birds.

Harvesting, consumption and trade of forest meat are key causes of biodiversity loss. Successful mitigation programs are proving difficult to design, in part because anthropogenic pressures are treated as internationally uniform. Despite illegal hunting being a key conservation issue in the Pacific Islands, there is a paucity of research. Here, we examine the dynamics of hunting of birds and determine how these contribute to biodiversity loss on the islands of Samoa. We focus on the interactive effects of hunting on two key seed dispersing bird species: the Pacific pigeon (Ducula pacifica) and the critically endangered Manumea or tooth-billed pigeon (Didunculus strigiristris). We interviewed hunters, vendors and consumers and analyzed household consumption. Results suggest that over 22,000 pigeons were consumed per year and this is by primarily the richest people across the country. Indeed, the wealthiest 10% of households consumed 43% of all wild pigeon meat, and the wealthiest 40% of households consumed 80% of all pigeons. The Manumea was shot by 33% (n = 30) of the surveyed hunters while pursuing the Pacific pigeon. Results raise serious conservation concerns, as pigeon hunting is likely to be a key factor contributing to the decline of the Manumea and critical forest seed dispersers in general. Our results show that wild meat consumption can lead to non-targeted pressure on bycatch species. Wild meat harvesting and consumption is a key issue leading to species declines and extinctions in the tropics. It is critical that this issue receives the appropriate attention and is addressed in the Pacific if species and forests are to be maintained.

Allee effects occur when survival or reproductive success declines with decreasing population size or density. Species most severely impacted by Allee effects may be the very species for which these effects will be hardest to detect and overcome. This impedes effective conservation through a lack of evidence to drive management actions. We review the literature to identify (1) component Allee effects (components of fitness) which could lead to a demographic Allee effect (effect of all components on the population growth rate) in bird populations; and (2) traits that make species susceptible to component Allee effects. Concurrently, we assess the potential for undetected Allee effects to negatively influence the population growth rate of 14 critically endangered Australian bird species or subspecies. Whilst some (e.g. Helmeted Honeyeater) are unlikely to suffer from a demographic Allee effect, several (e.g. Great Knot, Orange-bellied Parrot) are susceptible to a number of component Allee effects an...

Genetic tagging, the unique identification of individuals by their DNA profile, has proven to be an effective method for research on several animal species. In this study we apply non-invasive genetic tagging from feather samples to reveal the genetic structure and estimate local population size of red-and-green macaws (Ara chloropterus) without the need to capture these animals. The study was centered in the Tambopata region of the Peruvian Amazon. Here macaws frequently visit clay licks and their naturally molted feathers provide a unique source of non-invasively sampled DNA. We analyzed 249 feathers using nine microsatellite loci and identified 221 unique genotypes. The remainder revealed 21 individuals which were ‘recaptured’ one or more times. Using a capture-mark-recapture model the average number of different individuals visiting clay licks within one breeding season was estimated to fall between 84 and 316 individuals per clay lick. Analysis of population genetic structure revealed only small genetic differences among regions and clay licks, suggesting a single red-and-green macaw genetic population. Our study confirms the utility of non-invasive genetic tagging in harsh tropical environment to obtain crucial population parameters about an abundant parrot species that is very difficult to capture in the wild.

Population limitation is the outcome of cumulative and synergistic processes that act on species over multiple spatial scales. Tree cavity dependent animals are good case studies for exploring proc...

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.

Non-excavating species that prefer rare combinations of cavity traits are limited to only a fraction of the available tree cavity resource. Understanding animal preferences and quantifying the abundance of suitable cavities is fundamental to protecting non-excavators. We aimed to identify the traits of trees and cavities selected by a vulnerable, non-excavating bird, the superb parrot Polytelis swainsonii. We also evaluated cavity abundance and the accuracy of ground-based survey techniques (where an observer estimated the number of cavities in the canopy with binoculars from the ground). We then climbed trees to accurately identify true cavities and to measure their internal dimensions. Ground-based counts of tree cavities were correlated with the true number of cavity entrances in trees. When trees had zero cavities, ground counts overestimated their abundance, but for cavity-bearing trees ground counts underestimated their abundance. We found that superb parrot nest trees contained more cavities than random trees. Superb parrots selected cavities that were deeper, with wider floors and entrance sizes than random cavities. Cavities with the combination of selected traits comprised only 0.5% of the standing cavity resource. Our results confirm that non-excavators can be very selective about the types of trees and cavities they use for nesting. Rarity of suitable cavities may be a factor limiting the population growth and recovery of superb parrots. Without accounting for the critical information gap between what is observed on the ground, and what is in fact present in trees, effective habitat management for non-excavators may be compromised by inaccurate assessments of cavity abundance and conservation status.

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 c...

Migratory birds spend a large proportion of their lives within non-breeding habitats. However, knowledge of how they respond to variable winter resources is limited, especially for small migratory species. Citizen science programs provide an effective way to collect data on small migrants over large spatio-temporal scales. Here we present survey data for the Critically Endangered Swift Parrot (Lathamus discolor) that were collected by hundreds of volunteers over 7 years across the species’ winter range. Swift Parrots were detected in 23% of the 4035 surveys. Linear mixed models were used to examine variation in Swift Parrot abundance and correlations with climate variables. During non-drought years Swift Parrots concentrated within Victorian habitats. However, when Victoria was in drought, the response of the birds depended on the extent of drought conditions throughout the winter range. Consecutive years of drought in Victoria resulted in the population migrating over 1000 km further to drought refuge habitat in New South Wales. This study provides a rare demonstration of the large spatio-temporal responses of a migratory bird population to extreme climate conditions across its winter range. It demonstrates both variable and repeated use of winter habitats, and highlights the need for conservation management at large spatio-temporal scales.

Dispersal is essential for species persistence and landscape genetic studies are valuable tools for identifying potential barriers to dispersal. Macaws have been studied for decades in their natural habitat, but we still have no knowledge of how natural landscape features influence their dispersal. We tested for correlations between landscape resistance models and the current population genetic structure of macaws in continuous rainforest to explore natural barriers to their dispersal. We studied scarlet macaws (Ara macao) over a 13,000 km2 area of continuous primary Amazon rainforest in south-eastern Peru. Using remote sensing imagery from the Carnegie Airborne Observatory, we constructed landscape resistance surfaces in CIRCUITSCAPE based on elevation, canopy height and above-ground carbon distribution. We then used individual- and population-level genetic analyses to examine which landscape features influenced gene flow (genetic distance between individuals and populations). Across the lowland rainforest we found limited population genetic differentiation. However, a population from an intermountain valley of the Andes (Candamo) showed detectable genetic differentiation from two other populations (Tambopata) located 20–60 km away (F ST = 0.008, P = 0.001–0.003). Landscape resistance models revealed that genetic distance between individuals was significantly positively related to elevation. Our landscape resistance analysis suggests that mountain ridges between Candamo and Tambopata may limit gene flow in scarlet macaws. These results serve as baseline data for continued landscape studies of parrots, and will be useful for understanding the impacts of anthropogenic dispersal barriers in the future.

For small and rapidly declining populations acting fast to prevent extinction is crucial. However, many endangered species receive little attention or management action. Action paralysis can prevail for several reasons, particularly for data deficient species when conservation resources are scarce. Here we draw attention to one of the world’s rarest birds, the King Island Scrubtit (Acanthornis magnus greenianus), a subspecies of a monotypic genus. Recognised as critically endangered for more than two decades, conservation action is virtually non-existent despite a rapid population decline. To establish current baseline information using a repeatable cost-effective monitoring methodology we surveyed 154 sites at eight locations as well as additional sites within the agricultural matrix. We detected the King Island Scrubtit at 28 sites in three locations (Nook Swamp, Colliers Swamp and Pegarah State Forest). At these locations, we estimated overall occupancy to be 0.35 (s.e. 0.05) and detectability to be 0.68 (s.e. 0.05) during a single site visit. We estimate the current area of occupancy of the bird to be

Lethal control of invasive mammalian predators can be controversial and is rarely a ‘silver bullet’ for conservation problems. Evaluating the efficacy of lethal control is important for demonstrating the benefits to threatened species are real and detecting unexpected perverse outcomes. We implemented a pilot study to evaluate if lethal control of introduced sugar gliders Petaurus breviceps can reduce the rate of nest predation on Tasmanian hollow nesting birds including swift parrots (Lathamus discolor). Using a before-after-control-impact design, we implemented a lethal control treatment whereby we attempted to remove sugar gliders from three treatment sites. In each time period across sites we monitored quail eggs in nest boxes to record predation, and used cameras to detect sugar gliders. We caught nine sugar gliders over three treatment sites. The model best supported by the data indicated an effect of site×time period on both egg survival and the rate of glider detection on cameras. There was no support for an effect of treatment on our data. We also recorded predation of a real swift parrot nest by sugar gliders at a treatment site where we recorded no predation of quail eggs. Our pilot study shows that at small scales, intensive lethal control of gliders yields low capture rates and no discernible effect on the metrics we measured. We conclude that alternative approaches to controlling the impact of sugar gliders, such as habitat protection, are critical in this study system before lethal control is widely implemented as a management tool.

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.

The critically endangered regent honeyeater Anthochaera phrygia has suffered a severe population decline since the mid-nineteenth century. The contemporary population is estimated to consist of 200...

The positive abundance-occupancy relationship (AOR) is a pervasive pattern in macroecology. Similarly, the association between occupancy (or probability of occurrence) and abundance is also usually assumed to be positive and in most cases constant. Examples of AORs for nomadic species with variable distributions are extremely rare. Here we examined temporal and spatial trends in the AOR over 7 years for a critically endangered nomadic migrant that relies on dynamic pulses in food availability to breed. We predicted a negative temporal relationship, where local mean abundances increase when the number of occupied sites decreases, and a positive relationship between local abundances and the probability of occurrence. We also predicted that these patterns are largely attributable to spatiotemporal variation in food abundance. The temporal AOR was significantly negative, and annual food availability was significantly positively correlated with the number of occupied sites but negatively correlated with abundance. Thus, as food availability decreased, local densities of birds increased, and vice versa. The abundance-probability of occurrence relationship was positive and nonlinear but varied between years due to differing degrees of spatial aggregation caused by changing food availability. Importantly, high abundance (or occupancy) did not necessarily equate to high-quality habitat and may be indicative of resource bottlenecks or exposure to other processes affecting vital rates. Our results provide a rare empirical example that highlights the complexity of AORs for species that target aggregated food resources in dynamic environments.

Tree cavity dependent animals are sensitive to changes in cavity availability in forests. Fire is important in the long-term dynamics of cavity creation and loss, but there are few data on how fire impacts nesting resource availability for animals. We assessed the survival of 189 trees and 191 cavities used for nesting by an endangered secondary cavity nesting bird, the swift parrot Lathamus discolor, over a decade. A subset of monitored trees were burned in an uncontrolled fire. At the site of that fire, we compared swift parrot habitat quality before and after burning. We also evaluated the risk of total tree collapse due to stem destabilisation from basal scarring by calculating the critical failure stress for all monitored trees. Modelled persistence of unburned swift parrot nest cavities was more than twice that of scorched cavities over ten years. Likewise, unburned nest trees were more likely to still be standing at the end of the ten years than scorched trees. Fire caused an acute local increase in cavity and tree collapse. At the site of the fire, 62.8% of scorched nest cavities were destroyed compared to only 9.1% over the unburned remainder of the study area. Likewise, 48.6% of scorched nest trees collapsed at the fire affected site, compared to only 3.8% of unburned trees elsewhere. Burning associated tree collapse led to a significant decrease in tree diameter at breast height and number of potential cavities at monitored plots. This destroyed most of the existing nest cavity resource for swift parrots at the local scale and cavity abundance is unlikely to be replenished quickly. Loss of nesting resources may outweigh longer-term benefits of fire as an agent of cavity creation if animals miss opportunities for reproduction in locations where habitat is diminished by cumulative stochastic events and anthropogenic changes.

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.

Identifying the impact of introduced predators on endangered prey populations is critical for conservation management. Population viability analysis (PVA) becomes a valuable tool for quantifying such impacts when high quality life history data are available but, surprisingly, predictions from PVA of future population decline have seldom been used directly to assess conservation status. Here we synthesise new research on the unusual life history of the endangered swift parrot Lathamus discolor, an austral migrant that breeds in Tasmania, Australia. Swift parrots are challenging to monitor because (1) spatio-temporal fluctuation in food availability causes them to select entirely different breeding sites each year over a 10,000 km 2 range, and (2) they suffer high but variable rates of predation from introduced sugar gliders Petaurus breviceps depending on where they breed. 50.9% of nesting females on the main island of Tasmania were killed by sugar gliders while incubating eggs, but there was no predation from this source on offshore islands. Over four years 16.5% (0–29%) of the population bred on offshore islands. We use PVAs to examine the likely extent of future population decrease due to sugar glider predation, and demonstrate that the remaining swift parrot population is likely to decrease by 78.8–94.7% (mean over four models = 86.9%) over only three generations (12–18 years). Our models offer a rare example of the use of PVAs for assessing impending population decline and conservation status in species that are challenging to monitor. In this case they support a change of status for swift parrots from ‘‘Endangered’’ to ‘Critically Endangered’ under IUCN criteria.

Summary 1. Unlike philopatric migrants, the ecology of nomadic migrants is less well understood. This life-history strategy reflects responses to spatiotemporal variation in resource availability and the need to find resource rich patches to initiate breeding. The fitness consequences of movements between regions of patchily distributed resources can provide insight into ecology of all migrants and their responses to global change. 2. We link broad-scale data on spatiotemporal fluctuation in food availability to data on settlement patterns and fitness outcomes for a nomadic migrant, the endangered swift parrot Lathamus discolor. We test several predictions to determine whether facultative movements are adaptive for individual swift parrots in an environment where resources are patchily distributed over time and space. 3. Variation in the availability of swift parrot food resources across our study period was dramatic. As a consequence, swift parrots moved to breed wherever food was most abundant and did not resettle nesting regions in successive years when food availability declined. By moving, swift parrots exploited a variable food resource and reproduced successfully. 4. Exploiting the richest patches allowed swift parrots to maintain stable fitness outcomes between discrete breeding events at different locations. Unlike sedentary species that often produce few or lower quality offspring when food is scarce, nomadic migration buffered swift parrots against extreme environmental variation. 5. We provide the first detailed evidence that facultative movements and nomadic migration are adaptive for individuals in unpredictable environments. Our data support the widely held assumption that nomadic migration allows animals to escape resource limitation.

Species 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.

Only three wild-bred female Orange-bellied Parrots returned from migration in the 2016/17 breeding season, representing the lowest point of a long-term decline. In this context of imminent extinction risk we (i) update knowledge of population parameters, (ii) critically evaluate current recovery actions, and (iii) identify new management options. We present new data from the 2016/17 breeding season. Orange-bellied Parrots were only observed at the last known breeding site where fire suppression may havecaused shortage of natural food. Recently burned habitat elsewhere support abundant food, but no parrots. Fecundity of captive-bred individuals was significantly worse than wild-bred individuals (0.8 vs. 3 fledglings respectively), mostly due to infertility. Bacterial septicemia due to contaminated food caused mortalities of at least four nestlings. Fostering captive-bred nestlings to the wild showed some potential as a recovery tool, with 2 of 4 nests accepting a foster nestling, and one of these fledging successfully. Captive-bred birds had poorer feather condition than wild birds. Addressing food shortages and the addition of new managementactions to improve population recruitment are critical and urgent recovery priorities. We suggest recovery priorities for the species arising from our results, including emergency intervention to prevent imminent extinction.

In a rare parallel with human instrumental music, wild palm cockatoos manufacture sound tools and produce a rhythmic beat., 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.

Occupancy modelling using data collected by repeatedly sampling sites is a common approach utilised by land managers to understand species distributions and trends. Two important factors that can complicate interpretation of these models are imperfect detection and spatial autocorrelation. We examine the effect of these potential errors using a multi-year data set on the distribution of the migratory and endangered swift parrot (Lathamus discolor). We simultaneously account for these effects by extending a zero-inflated Binomial (ZIB) framework to allow the inclusion of semiparametric, smooth spatial terms into both the occupancy and detection component of the model, in a maximum likelihood framework easily implemented in common software. This approach also has the advantage of relatively straightforward model selection procedures. We show that occupancy and detectability were strongly linked to food availability, but the strength of this relationship varied annually. Explicitly recognising spatial variability through the inclusion of semiparametric spatially smooth terms in the ZIBs significantly improved models in all years, and we suggest this predictor is an effective proxy for unmeasured environmental covariates or conspecific attraction. Importantly, the spatially explicit ZIBs predicted fewer occupied sites in more defined areas compared to non-spatial ZIBs. Given the importance of predicted distributions in land management, habitat protection and conservation of swift parrots, these models serve as an important tool in understanding and describing their ecology. Our results also reinforce the need for designing surveys that capture the underlying spatial structure of an ecosystem, especially when studying mobile aggregating species.

Aim Introduced predators are a global driver of species decline, but their impact on highly mobile species is poorly understood. We report the severe impact of a previously undocumented introduced predator on the endangered, migratory swift parrot (Lathamus discolor). Sugar gliders (Petaurus breviceps), a supposedly benign introduced species, were detected acting as a major opportunistic predator of cavity-nesting birds. We assessed the intensity and geographical extent of sugar glider predation and investigated whether habitat loss exacerbated predation risk to swift parrots. Location Tasmania, Australia. Methods We monitored nests of swift parrots for 3 years with motion-activated cameras. We used bioclimatic modelling to predict the potential distribution of introduced sugar gliders across the study area and assessed the predation risk to swift parrots and other threatened birds in the region using nest-survival analysis. Results Daily survival of nests in areas where sugar gliders occurred was mean 0.97, which equated to a true likelihood of 0.17 for a nest to survive the 60-day nesting period. No nests failed on an offshore island where sugar gliders were shown to be absent. Most cases (83.3%) of glider predation resulted in the death of the adult female parrot. On the Tasmanian mainland, there was a positive relationship between nest survival and increasing mature forest cover at the landscape scale. Main conclusions Predation risk varied dramatically across the breeding range of swift parrots, depending on the presence of sugar gliders. Offshore islands are an important refuge for swift parrots because sugar gliders are absent. However, islands are vulnerable, and our bioclimatic model shows that they are bioclimatically suitable for sugar gliders. Synergistic interactions between predation and habitat loss combine with low breeding-site philopatry to expose swift parrots to dramatic variation in predation risk depending on nesting location.

Psittacidae (parrots) have the most threatened species of any bird family in the world. Most parrots are obligate secondary cavity nesters, and can be limited in their breeding success by the availability and quality of nest hollows. However, nesting opportunities for parrots can be increased by provision of artificial nest boxes. The Tambopata Macaw Project has been studying the breeding ecology and natural history of the Scarlet Macaw Ara macao macao in the south-eastern Peruvian Amazon for over 20 years by monitoring natural nest hollows and two types of artificial nest (wooden and PVC). We present data for breeding success in natural and artificial nests over 12 consecutive breeding seasons. The aims of this study were to: (a) determine the nesting requirements and reproductive success of breeding macaws; and, (b) compare the efficacy of the two types of artificial nests and natural nest cavities. Our data showed a high rate of reoccupation of successful nests in consecutive years and that nests in artificial and natural nests had very similar reproductive parameters. Our results indicate that artificial nest types can be used by conservation managers seeking to assist A. macao populations where nest hollows are in short supply, and that artificial nests can contribute important data to natural history studies of species where access to natural nests is limited.