Regent Honeyeater Research Articles

Frequency-dependence may moderate fitness costs linked to reduced bird song complexity.

Animal cultures can undergo rapid changes associated with innovations, revolutions or population decline. Where a rapid shift results in reduced complexity of cultural behaviours, it may have fitness consequences for individuals. Here, we report a dramatic shift in the dominant song type of critically endangered wild regent honeyeaters Anthochaera phrygia. Between 2015 and 2019, most males in the Blue Mountains sang a typical regent honeyeater song (typical Blue Mountains song), but 5%-10% sang an abbreviated version of the song with half the number of syllables (the clipped Blue Mountains song), which was associated with lower pairing success. Since 2020, the proportion of males singing the clipped Blue Mountains song has increased to 50%-75% each year. The likelihood of successful pairing in these males showed a significant concomitant increase, suggesting that the fitness costs associated with the abbreviated song decreased as it became the dominant song type. Our results suggest that the fitness consequences of loss of song complexity in declining and fragmented populations may be ameliorated by frequency-dependent shifts in song type preference.

A bird, a flock, a song, and a forest: The decline of Regent Honeyeater life

AbstractThe south‐eastern corner of the Australian continent was once crisscrossed by the nomadic flight paths of the Regent Honeyeater. For hundreds of thousands of years, they winged their way up and down this vast continent. Today, however, the species is listed as critically endangered and is just clinging to existence. This multimedia essay tells the story of this decline, exploring the complex, co‐shaping, relationships between individual birds and their flocks, their songs, and their forests. While these are relationships that might be glossed as being social, cultural, and ecological (respectively), and so belonging to separate domains of life, they are in reality delicately interwoven elements of what it is to be a Regent Honeyeater; relationships that, taken together, have been integral to the emergence and ongoing life of this species. In attending to the breakdown of these relationships in our present time, this essay seeks to develop new resources for storying loss in a time of ongoing extinctions. Bringing text into conversation with images and audio, the essay works to draw the reader/viewer/listener into an encounter with an unravelling world. Ultimately, our aim has been to create an essay in which the conceptual ideas, the design, and the biology of the species described, are brought into some sort of alignment that allows them to become mutually reinforcing elements of a storied encounter. Our reflection on the process of creating this essay are provided in the accompanying exegetical commentary.

Zoo-bred female birds prefer songs of zoo-bred males: Implications for adaptive management of reintroduction programs

Understanding the factors affecting the success of animal reintroductions is crucial for facilitating endangered species recovery. Cultural differences between individuals from different animal populations can lead to assortative mating, whereby individuals prefer to breed within their own familiar cultural cohort. Assortative mating can hinder the assimilation of zoo-bred individuals into wild populations, so quantifying this risk becomes important for informing adaptive management strategies in conservation. We conducted mate choice experiments on zoo-bred female regent honeyeaters (Anthochaera phrygia) to assess whether they showed stronger behavioural responses to the familiar but abnormal songs of zoo-bred male regent honeyeaters than those of their wild counterparts or an interspecific control song. Female regent honeyeaters were no more likely to enter the playback aviary in response to the songs of zoo-bred males than those of wild males or a different species. However, females that did enter the playback aviary were significantly more likely to respond quickly, approach the speaker closely and remain in the playback aviary for longer in response to the songs of zoo-bred males than wild songs or control songs. Our study is the first to show experimentally that zoo-bred females prefer familiar, but abnormal, zoo-bred songs over unfamiliar wild-type songs. We suggest that assortative mating amongst released birds is a risk in reintroduced regent honeyeaters, given recent evidence that the breeding success of reintroduced pairs is low. Our study demonstrates how small-scale experiments conducted within applied zoo-breeding settings can yield useful information to refine husbandry techniques and reduce cultural divides between wild and reintroduced populations.

Towards effective management of an overabundant native bird: The noisy miner

AbstractAddressing threats to biodiversity from pest species is a global challenge. One such challenge is to mitigate the impact of an overabundant Australian songbird, the noisy minerManorina melanocephala,on woodland birds. The overabundance of noisy miners is listed as a key threatening process under federal biodiversity legislation, but current understanding of where and how noisy miner populations can be managed to yield conservation benefits is unclear. We evaluated the effectiveness of noisy miner removal across 12 treatment areas totaling 3913 ha and nine control areas totaling 1487 ha important for the critically endangered regent honeyeaterAnthochaera phrygia. Removal of noisy miners significantly reduced their densities in all but one of the treatment areas. In 10 of the 12 treatment areas, noisy miner densities remained below an impact threshold of 0.65–0.83 birds ha−1for at least 3 to more than 12 months. The percentage of suitable noisy miner habitat in the surrounding landscape was not a strong predictor of noisy miner management success. Regent honeyeaters occupied six treatment areas, nesting successfully in four. The abundance of other songbirds increased post‐miner removal in seven areas, decreased in three, and was mixed in two. Data from the control areas showed some variation in songbird numbers was independent of noisy miner management. We conclude that noisy miners can be managed in areas of high conservation value for a minimum cost of AUD $10 ha−1. Larger treatment areas may be more important than the broader landscape context in maintaining long‐term noisy miner suppression. Standardized, long‐term monitoring is crucial to identify not only the drivers of pest species recolonization but also locations where threats from pests on endangered species can be addressed effectively while minimizing animal welfare and financial costs.

Population viability in data deficient nomadic species: What it will take to save regent honeyeaters from extinction

The long-distance, unpredictable movement patterns of nomadic species make them challenging to monitor and conserve. Critically endangered regent honeyeaters Anthochaera phrygia once roamed south-eastern Australia in ‘immense flocks’ but now number fewer than 300 wild birds over a vast 300,000 km2 range. Regent honeyeaters are a rare example where extensive monitoring data are now available for a nomadic species, enabling evaluation of the impact of management actions using population viability analysis (PVA). We combined demographic estimates from wild population monitoring in the 1990s, a zoo-based supplementation program and a contemporary range-wide monitoring program to simulate the wild population trajectory under various management and climatic scenarios. Without intervention, our models predicted extinction within 20 years, and showed that management strategies at their current intensity have limited efficacy to prevent extinction. Conservation actions should aim to increase the size and density of the wild population so that Allee effects no longer suppress population growth. Protection of wild regent honeyeater nests is essential as breeding success has declined over recent decades and droughts increasingly reduce breeding opportunities. Our models emphasise the need for zoo-based breeding to bolster the wild population, but show that release of zoo bred birds into the wild only slows the rate of population decline. To recover the wild regent honeyeater population, the next five years will be critical for implementing the most effective conservation strategy. This requires a combination of nest protection and release of zoo-bred birds with improved fitness, predator suppression, habitat protection and increased rates of habitat restoration.

A range‐wide monitoring programme for a critically endangered nomadic bird

AbstractNomads challenge the prevailing approach to species conservation because their unpredictable resource‐driven movements hamper data collection. We developed a monitoring approach to address the conservation needs of critically endangered, nomadic regent honeyeaters Anthochaera phrygia, whose unpredictable movements occur at a continental scale. We used species distribution models that incorporated lagged effects of environmental variation on habitat suitability to refine and prioritise monitoring. By incorporating lagged effects of weather on occurrence, we identified a priority area within which we selected sites to survey. We undertook 1695 surveys in 2016 at 777 priority sites, and in 2017, we conducted a further 1434 surveys at 859 sites. We discovered nesting regent honeyeaters at new locations, locating 218 regent honeyeaters over two years. We validated performance of our priority mapping with the 2016–2017 survey results and the results of Crates et al. (J. Wildl. Manage. 2017, 81, 669). Predictive performance of the priority monitoring range map was best at estimated model values of approximately 0.7 and declined at both higher and lower values. Water availability was an important predictor, but poor resolution of the underlying data used in SDMs (e.g. temporary water sources) may explain our model performance. By accounting for spatiotemporal weather variation, we show that regional habitat suitability within the range of regent honeyeaters varied dramatically among years. Incorporating dynamic weather conditions is a useful approach to designing monitoring programmes for nomads. Our approach shows how to compromise between the need to account for the dynamic environmental conditions that drive site occupancy of nomads and the practical logistic constraints of implementing monitoring with scarce resources.

Poor‐quality monitoring data underestimate the impact of Australia's megafires on a critically endangered songbird

AbstractAimCatastrophic events such as south‐eastern Australia's 2019/20 megafires are predicted to increase in frequency and severity under climate change. Rapid, well‐informed conservation prioritization will become increasingly crucial for minimizing biodiversity losses resulting from megafires. However, such assessments are susceptible to bias, because the quality of monitoring data underpinning knowledge of species' distributions is highly variable and they fail to account for differences in life history traits such as aggregative breeding. We aimed to assess how impact estimates of the 2019/20 megafires on the critically endangered regent honeyeater Anthochaera phrygia varied according to the quality of available input data and assessment methodology.InnovationUsing Google Earth Engine Burnt Area Mapping, we estimated the impact of the megafires on the regent honeyeater using six monitoring datasets that differ in quality and temporal span. These datasets are representative of the variable quality of monitoring data available for assessing fire impact on 326 other threatened species; most are poorly monitored, and few have standardized, species‐specific monitoring programmes. We found that assessments based on area of occupancy (AOO), extent of occurrence (EOO) and public sightings underestimated the fire impact relative to recent, targeted monitoring datasets: a MaxEnt model, sightings from a national monitoring programme and nest locations since 2015. Using an impact threshold of 30% of habitat burned, regent honeyeaters would not meet these criteria using estimates derived from EOO, AOO or public sightings, but would exceed the cut‐off based on estimates derived from the targeted monitoring data that account for population density.Main conclusionsTo ensure that conservation prioritization has the greatest capacity to minimize biodiversity losses, we highlight the need to improve targeted, threatened species monitoring. We demonstrate the importance of using recent, standardized monitoring data to estimate accurately the impact of major ecological disturbances, particularly for declining, nomadic species undergoing range contractions.

Landscape‐scale distribution of nest predators and its relationship with regent honeyeater nest success

AbstractOvercoming low breeding success is a major challenge for reversing population decline in threatened species. High nest predation rates are a common cause of low productivity in birds, but implementing evidence‐based management actions to reduce nest predation is challenging. Targeted breeding management requires a good understanding of where threatened species breed, the identity and distribution of nest predator species and the impact of these nest predators on breeding success. For rare and nomadic species, this information is hard to come by. The breeding success of regent honeyeater Anthochaera phrygia has declined over recent decades, and nest predation is the primary cause of breeding failure. We conducted point‐count surveys of nine avian and three mammalian nest predator species across 80% of the regent honeyeater’s contemporary breeding area in south eastern Australia. We used occupancy models to determine the presence of predator species at survey sites and spatial models to predict predator abundance and species richness across the breeding area. We incorporated predator predictions for regent honeyeater nest locations into nest fate and daily nest survival models. Predator abundance was correlated positively with tree hollow abundance and proximity to water and negatively with shrub cover. Regent honeyeater nest success showed no significant relationship with predator abundance or predator species richness. Given how abundant and widespread avian and mammalian nest predators were throughout the breeding area, improving regent honeyeater nest success is likely to require implementation of simultaneous nest protection measures to avoid potential compensatory nest predation. Further research is required to better understand the relationship between nest predator abundance and regent honeyeater nest success.

Born to Be Wild: Evaluating the Zoo-Based Regent Honeyeater Breed for Release Program to Optimise Individual Success and Conservation Outcomes in the Wild

Evaluating the effectiveness of captive breeding programs is central to improving conservation outcomes in released animals. However, few studies have assessed the impact of the strategies and trade-offs involved in husbandry decisions and the selection of traits on the success of breeding programs. This study evaluated a range of husbandry features including an animal's environment, health, and traits of the released individual and its parents involved in the zoo-based Regent Honeyeater breed for release program to optimise individual reproductive success and survivability, leading to improved conservation outcomes in the wild. We analysed 285 birds using a penalised Cox proportional hazard model to assess survival and an ordinal logistic model to evaluate the reproductive success of zoo bred birds released to the wild. Key features identified by the study highlight the importance of having parents that are successful breeders and parents that have an overall higher lifetime reproductive output. However, there were associated quantity-quality trade-offs, as the success of young (i.e., released birds) produced by parents was negatively associated to the number of clutches per year (where one clutch per year was found optimal). The study demonstrated the importance of considering the parental effects on the traits of its offspring beyond its pedigree information and found there was an associated decline in fitness of its offspring with older fathers. Song tutoring using wild Regent Honeyeaters was also important for increased survival post-release. Other important factors are discussed within the review. In general, the study recommended that a multi-faceted approach in the assessment and evaluation of the captive breeding program, to identify markers that will improve conservation outcomes of future releases.

Loss of vocal culture and fitness costs in a critically endangered songbird.

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.

Meta-transcriptomic identification of Trypanosoma spp. in native wildlife species from Australia

BackgroundWildlife species carry a remarkable diversity of trypanosomes. The detection of trypanosome infection in native Australian fauna is central to understanding their diversity and host-parasite associations. The implementation of total RNA sequencing (meta-transcriptomics) in trypanosome surveillance and diagnosis provides a powerful methodological approach to better understand the host species distribution of this important group of parasites.MethodsWe implemented a meta-transcriptomic approach to detect trypanosomes in a variety of tissues (brain, liver, lung, skin, gonads) sampled from native Australian wildlife, comprising four marsupials (koala, Phascolarctos cinereus; southern brown bandicoot, Isoodon obesulus; swamp wallaby, Wallabia bicolor; bare-nosed wombat, Vombatus ursinus), one bird (regent honeyeater, Anthochaera phrygia) and one amphibian (eastern dwarf tree frog, Litoria fallax). Samples corresponded to both clinically healthy and diseased individuals. Sequencing reads were de novo assembled into contigs and annotated. The evolutionary relationships among the trypanosomatid sequences identified were determined through phylogenetic analysis of 18S rRNA sequences.ResultsWe detected trypanosome sequences in all six species of vertebrates sampled, with positive samples in multiple organs and tissues confirmed by PCR. Phylogenetic analysis indicated that the trypanosomes infecting marsupials were related to those previously detected in placental and marsupial mammals, while the trypanosome in the regent honeyeater grouped with avian trypanosomes. In contrast, we provide the first evidence for a trypanosome in the eastern dwarf tree frog that was phylogenetically distinct from those described in other amphibians.ConclusionsTo our knowledge, this is the first meta-transcriptomic analysis of trypanosomes in native Australian wildlife, expanding the known genetic diversity of these important parasites. We demonstrated that RNA sequencing is sufficiently sensitive to detect low numbers of Trypanosoma transcripts and from diverse hosts and tissues types, thereby representing an effective means to detect trypanosomes that are divergent in genome sequence.

Ecology and conservation of the regent honeyeater

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...

Sustained and delayed noisy miner suppression at an avian hotspot

AbstractTo mitigate the impact of noisy miners Manorina melanocephala on Australia’s woodland birds, there is a need to identify locations where noisy miner suppression can be affordable, sustainable and facilitate woodland bird recovery. In 2017, we suppressed noisy miners from the Goulburn River, NSW for at least three months. During this period, six pairs of critically endangered regent honeyeaters nested in the treatment area. In 2018, we continued monitoring the original noisy miner treatment area, which was expanded to include our 2017 control area, and established a new control area downstream. In 2019, the removal effort was again expanded to include the 2018 control area. In the 2017 treatment area, noisy miners remained suppressed up to 27 months post‐removal. Their numbers here were lower 1 year after the initial cull than in the week after it. In the 2018 and 2019 treatment areas, noisy miner abundance was significantly lower after respective culls than at all pre‐removal periods. In 2018, around 20 vulnerable painted honeyeaters occupied the 2018 treatment area. In 2019, two regent honeyeater pairs nested in and at least 40 painted honeyeaters occupied the treatment area. Songbird abundance increased within seasons and also up to a year following noisy miner removal, and plateaued thereafter. We show how, in strategic locations, a week of noisy miner suppression each spring can sequentially create ever‐larger landscapes where noisy miner impacts on threatened woodland birds are minimal.

Risk aversion and uncertainty create a conundrum for planning recovery of a critically endangered species

AbstractMaking transparent and rational decisions to manage threatened species in situations of high uncertainty is difficult. Managers must balance the optimism of successful intervention with the risk that intervention could make matters worse. We assessed nest protection options for regent honeyeaters (Anthochaera phrygia) in Australia. Formal expert elicitation highlighted two methods of nest protection expected to improve nest success. However, the risks and benefits of different actions were uncertain; for example, protecting nests from predators might also increase the risk of nest desertion by adults. To avoid risks, the recovery team opted to collect more information before implementation. The two methods of nest protection were compared using a field experiment. However, the same risk aversion limited the experiment to a single variable (nest predation) and dictated the use of artificial nests. The results of the experiment suggested neither action was likely to significantly reduce predation risks (<3% mean differences in survival between treatment and control). When presented with these results, managers made only minor revisions to their estimates; in part, this reflected low confidence by managers that artificial nests could reflect real predation risks. However, estimates were also revised more negatively for the initially less‐favored option, despite absence of such evidence, possibly highlighting confirmation bias. In this uncertain situation, the status quo was initially maintained although it was perceived as suboptimal; implementation of the preferred option (tree collars) is now planned for the 2019 breeding season. We faced what might be a common conundrum for conservation of critically endangered species. High uncertainty affects management decisions; however, perilous species status also leads to strong risk aversion, which limits both the willingness to act on limited information and the ability to learn effectively. Structured methods can increase transparency, facilitate evaluation, and assist decision making, but objective limitations and subjective attitudes cannot be circumvented entirely.

Genomic impact of severe population decline in a nomadic songbird.

Uncovering the population genetic histories of non-model organisms is increasingly possible through advances in next generation sequencing and DNA sampling of museum specimens. This new information can inform conservation of threatened species, particularly those for which historical and contemporary population data are unavailable or challenging to obtain. The critically endangered, nomadic regent honeyeater Anthochaera phrygia was abundant and widespread throughout south-eastern Australia prior to a rapid population decline and range contraction since the 1970s. A current estimated population of 250–400 individuals is distributed sparsely across 600,000 km2 from northern Victoria to southern Queensland. Using hybridization RAD (hyRAD) techniques, we obtained a SNP dataset from 64 museum specimens (date 1879–1960), 102 ‘recent’ (1989–2012) and 52 ‘current’ (2015–2016) wild birds sampled throughout the historical and contemporary range. We aimed to estimate population genetic structure, genetic diversity and population size of the regent honeyeater prior to its rapid decline. We then assessed the impact of the decline on recent and current population size, structure and genetic diversity. Museum sampling showed population structure in regent honeyeaters was historically low, which remains the case despite a severe fragmentation of the breeding range. Population decline has led to minimal loss of genetic diversity since the 1980’s. Capacity to quantify the overall magnitude of both genetic diversity loss and population decline was limited by the poorer quality of genomic data derived from museum specimens. A rapid population decline, coupled with the regent honeyeater’s high mobility, means a detectable genomic impact of this decline has not yet manifested. Extinction may occur in this nomadic species before a detectable genomic impact of small population size is realised. We discuss the implications for genetic management of endangered mobile species and enhancing the value of museum specimens in population genomic studies.

Spatially and temporally targeted suppression of despotic noisy miners has conservation benefits for highly mobile and threatened woodland birds

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.

Contemporary breeding biology of critically endangered Regent Honeyeaters: implications for conservation

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.

Video monitoring reveals novel threat to Critically Endangered captive-bred and released Regent Honeyeaters

ABSTRACTNest predation is a primary cause of nest failure in open-cup nesting woodland birds and low reproductive success is a common reason why reintroduced species fail to establish in the wild. We used video monitoring to record the breeding outcomes and identify the causes of nest failure in a reintroduced population of the Critically Endangered Regent Honeyeater. We intensively monitored 28 nesting attempts of 13 pairs during the 2015 breeding season, and found that the probability of individual nest success was 0.21 (from egg laying to fledging). We report for the first time Sugar and Squirrel Gliders depredating Regent Honeyeater nests. In addition to losses attributed to predation, a high proportion of chicks died in the nest from unknown causes. Our results show that rates of nest initiation and success are low in reintroduced Regent Honeyeaters, and future reintroductions should attempt to mitigate the threat of nest predation. Other sources of nest failure and barriers to nest initiation and egg laying are priority areas for future research.

Enhancing seedling survival on former floodplain grazing land in the Capertee Valley, Australia

SummaryActive revegetation is an essential component of biodiversity conservation for fragmented ecosystems and the species that depend on them. However, key knowledge gaps exist around the most cost‐effective revegetation strategies to employ in different contexts. This article reports on a revegetation trial undertaken in the Capertee Valley of New South Wales, Australia, to assist the conservation of the critically endangered bird, the Regent Honeyeater (Anthochaera phrygia). Seven treatments were compared to assess their cost‐effectiveness for enhancing plant survival at a floodplain site with a history of grazing on introduced pastures. While overall survival rates were low, treatments involving tree guards had higher survival rates and were more cost‐effective than treatments without guards. Weed growth, animal activity and water stress all appeared to play a role in the low survival rates at this site, with enhanced weed control emerging as a priority for future trials at similar sites.

An occupancy approach to monitoring regent honeyeaters

ABSTRACTConservation of rare and highly mobile species is frequently limited by a lack of monitoring data. Critically endangered regent honeyeaters (Anthochaera phrygia, population 350–400) pose a substantial conservation challenge because of their high mobility and irregular settlement throughout their estimated 600,000‐km2 range. Given an ongoing population decline, enhanced monitoring efforts to inform population management are needed. We conducted an occupancy survey of regent honeyeaters and other nectarivores over 880 km2 of the species' core range in New South Wales, Australia, during spring 2015. We located approximately 70 regent honeyeaters, potentially representing 20% of the population. Presence of regent honeyeaters was best predicted by high local nectar abundance. Detectability of regent honeyeaters when breeding (0.59) was similar to common, co‐occurring nectarivores and was sufficient to distinguish absence from non‐detection. For rare and highly mobile species, monitoring approaches that prioritize sampling extent over site visit duration and explicitly accommodate their life‐history attributes can provide valuable population data, with subsequent benefits for conservation. © 2017 The Wildlife Society.