Understanding sex-related differences in ecology is essential for effective conservation strategies, especially in species that exhibit subtle to no sexual dimorphism. This study examines the Desert Uplands population of the Southern Black-throated Finch (Poephila cincta cincta); an endangered species endemic to north-eastern Australia, focusing on key ecological aspects, including sex ratio, movement ecology, and diet. Although previously considered sexually monomorphic, we found subtle sexual dimorphism in throat patch size (17.1% larger in males) and wing length (7.48% larger in males), with no significant differences in other morphological traits. We found a balanced adult sex ratio (52.3% females, 47.7% males), indicating no significant sex bias; a key indicator for ensuring mating opportunities and breeding success. Despite these differences, only 67.6% of individuals could be sexed accurately based on these traits. We also examined the movement ecology of the species and found no significant sex-based differences in home range size or movement distance, consistent with the subspecies' tendency to live in mixed-sex flocks. Diet analysis, based on DNA metabarcoding of crop and faecal samples, indicated no significant sex-based dietary divergence, with both sexes consuming a similar variety of grass seeds. These findings highlight the importance of understanding the ecological dynamics of the Southern Black-throated Finch for conservation efforts, suggesting that further studies on juvenile dispersal, and advanced morphometric techniques may improve understanding of this species.
Bird assemblages were surveyed on two adjoining conservation reserves in north-western NSW over six years through a sequence of dry - wet - dry conditions that included Australia's driest and warmest year on record. Surveys aimed to identify bird-habitat associations and assess changing abundances. Species richness was highest in 'wet' years, but in contrast to all previous studies, total bird abundance was highest in the two driest years driven by the superabundance of two Eyrean nomadics, Masked Woodswallow (Artamus personatus) and White-browed Woodswallow (Artamus superciliosus), coinciding with Yapunyah (Eucalyptus ochrophloia) flowering events. Seven broad patterns of species abundance were found. Less than half (42.5%) of the bird species were consistently present. Inter-annual differences in the composition of bird assemblages were mostly due to nomadic species. Diet was a reasonable predictor of movement behaviour but foraging guilds did not map directly onto movement groups. Each foraging guild had species with different movement behaviours and vice versa. Patterns of species' abundances did not always conform to their expected movement behaviour. Both vegetation and rainfall had a role in structuring bird assemblages. Variation in bird assemblages was significantly correlated with remotely sensed Normalized Difference Vegetation Index (NDVI).
The international trade of exotic birds is a growing phenomenon with important ecological and sanitary implications, particularly for countries with high biodiversity and expanding pet markets. In this study, we provide the first comprehensive characterisation of legal exotic bird imports into Chile, analysing their taxonomic and geographic diversity, temporal trends, intended use and potential biological risks. We compiled and examined official import records from 2013 to 2024, documenting 255 species from 37 families and 17 countries. Trade activity fluctuated markedly over time, increasing during the mid- and late 2010s, peaking in 2018-2019, and declining during the period affected by the SARS-CoV-2 pandemic. The most frequently imported species included Serinus canaria, Platycercus elegans and Psittacula krameri, all of which are considered invasive in other countries or regions. We also assessed the phylogenetic relatedness between imported and native Chilean avifauna, identifying several exotic taxa closely related to native species. Many of the imported birds are known to harbour infectious agents, posing potential risks to native bird communities and public health. Overall, this study provides critical baseline data to support future research and inform ecological and sanitary risk assessments related to exotic bird trade in Chile, while also offering a framework that may be applied in other countries facing similar challenges.
Antagonistic interactions between humans and wildlife are uncommon among Neotropical predators. Although raptors account for most documented avian attacks on humans, nocturnal species remain poorly studied due to their cryptic behaviour and low detectability, resulting in substantial knowledge gaps regarding their ecology and interactions with people. Here, we report the first documented case of an attack by a free-ranging Great Horned Owl (Bubo virginianus) on humans in Brazil. The observation was based on a single incident, followed by field surveys conducted at the site of the attack. No nests or additional individuals were detected, and the owl showed no signs of being provoked or acting in self-defence. Plausible explanations for the event are the presence of prey in the area, which may have triggered aggressive behaviour, or that the individual had become habituated to humans during rehabilitation and captivity. Documenting rare behavioural events such as this contributes to a better understanding of human-raptor interactions and may aid in developing preventive measures to reduce future conflicts while promoting coexistence.
The Letter-winged Kite (Elanus scriptus), a raptor endemic to the arid interior of Australia, is the only nocturnal member of the Accipitridae family and remains one of the country's least studied birds. Currently listed as Near Threatened in the IUCN RedList but Least Concern in Australian federal legislation, its population status and distribution are poorly understood, with anecdotal evidence indicating an ongoing decline. However, no comprehensive, range-wide assessment of population trends has been conducted, creating a significant knowledge shortfall that may hinder timely conservation action. In this study, we leveraged citizen science datasets on Australian birds to compile what is, to our knowledge, the first comprehensive occurrence database for the Letter-winged Kite. We integrated historical and contemporary records with current ecological understanding to establish a baseline assessment of the species' population trends and distribution. Utilising three potential hypotheses around decline, our analysis suggests that, while the species remains relatively stable within its core range, irruptive events into peripheral areas are occurring with decreasing frequency, scale and abundance. We argue that the Letter-winged Kite exemplifies the need for a more precautionary approach to species' conservation listings. Despite data deficiencies, existing evidence supports elevating the species' conservation status to Vulnerable based on its small, contiguous population and consistent signs of decline suggestive of an ongoing range contraction. We believe this designation is both warranted and necessary to ensure appropriate conservation attention is directed towards the species, until such time that more robust data can confirm or refute the extent of its decline.
Recent molecular and morphological studies have argued that the smaller bodied fig-parrots long assigned to the genus Cyclopsitta Reichenbach, 1850 warrant placement in two genera. AviList, the 2025 global list of the world's birds, agreed but advocated the use of the generic name Nannopsittacus Mathews, 1916, rather than Suavipsitta Mathews, 1917, for the New Guinean fig-parrots currently linked to the species epithets gulielmitertii, melanogenia and nigrifrons. Although entirely in keeping with the present International Code of Zoological Nomenclature, this strains common sense and invites ridicule of the Code because some South American parrotlets have for decades longer been assigned to the almost identically spelled Nannopsittaca Ridgway, 1912. I show that, remarkably enough, Mathews himself realised the risk of confusion between Ridgway's Nannopsittaca and his own Nannopsittacus and that that is why he introduced Suavipsitta to replace his own name Nannopsittacus all in the same Volume of his Birds of Australia Volume 6. Having two so similar generic names within an Order of birds clearly risks confusion and misuse in the literature. I conclude that the Zoological Code should be changed to follow the International Code for Nomenclature of algae, fungi and plants (Shenzhen Code) and simply not allow such confusingly similar generic names.
The Moluccan Scrubfowl (Eulipoa wallacei), an endemic megapode of the Moluccan Islands, is declining due to egg harvesting and degradation of coastal nesting habitats. This study investigated the spatial structure, burrow architecture and microhabitat characteristics of nesting sites at Tanjung Maleo, Haruku Island, Indonesia. Field observations were conducted at four active nesting sites using direct excavation, digital planimetry and quantitative analyses, including regression, Pearson correlation and the Morisita index. Measured variables included nest density, inter-nest distance, burrow dimensions, substrate temperature and moisture, and sand texture. Nest number increased with site area, while nest density showed a weak negative relationship with area, indicating spatial suitability and microhabitat preference. Nest distribution was uniform, with a mean inter-nest distance of 7.70 +/- 4.63 m. Burrows were steeply inclined (60.85 degrees +/- 7.42 degrees) with relatively constant diameters (19.99 +/- 1.71 cm) and stable incubation conditions (26.38 +/- 2.57 degrees C; 92.57 +/- 7.03% moisture). Only diagonal and vertical depths were strongly correlated. Nesting substrates were dominated by homogeneous medium sand that was consistent across sites, indicating strong selection for specific sand characteristics. Nesting sites were consistently located in open coastal areas above the highest tidal line. Spatial patterns reflect a scale-dependent strategy, in which uniform distribution at broader scales coexists with localised clustering driven by microhabitat suitability. Overall, these findings highlight a distinct tropical coastal burrow-nesting strategy and emphasise the importance of conserving open sandy coastal habitats, as well as regulating human use, to ensure nesting site availability and long-term reproductive success.
Understanding the relative influence of individual threats on species decline is essential for effective conservation planning. This is particularly challenging for species that declined historically, as early losses leave limited records from which to infer past distributions. The southern subspecies of the Squatter Pigeon (Geophaps scripta scripta), a granivorous bird from eastern Australia, experienced a substantial range contraction in the early 1900s. Reported causes of decline include land clearing, habitat degradation and feral predators; however, the relative importance of these threats has not been quantified. To address this gap, we developed an ensemble species distribution model (SDM) to evaluate the influence of environmental variables and threatening processes on the contemporary relative likelihood of occurrence (RLO) of the Southern Squatter Pigeon. We then hindcasted historical habitat extent using environmental conditions and threat distributions prior to European colonisation to infer how the subspecies' range may have contracted. Contemporary suitable habitat was estimated at approximately 359,500 km2, primarily in central and northern Queensland. Hindcasting estimated a historical habitat extent of approximately 688,000 km2, representing an approximate 48% decline in RLO. Habitat losses were concentrated in inland New South Wales and southern Queensland. Among threatening processes, red fox density had the strongest negative association with Southern Squatter Pigeon RLO. Cat density was a comparatively weak negative predictor of Southern Squatter Pigeon RLO, and habitat condition showed only a minor influence. Overall, these findings identify the red fox as the primary threat to the Southern Squatter Pigeon.
Female ornamentation as a signal of mate quality has been historically understudied. In bird species where females build the nest, nest morphology - a repeatable and heritable trait in some taxa - may function as an extended phenotypic signal subject to natural or sexual selection. In Diamond Firetails (Stagonopleura guttata), females differ in their ornamentation, measured as the number of white flank spots ('spottiness'), a trait linked to dominance, reproductive investment, and immune strength. Female Diamond Firetails are the sole builders of the nest, and nests often differ in their morphology, notably in the length of the entrance tunnel. We aimed to investigate the relationship between the phenotype of the nest builder, clutch size and nest architecture, and how nest architecture affects depredation risk. We analysed female morphology (mass, tarsus length, spottiness), nest morphology (nest height, nest length, entrance tunnel length), and clutch size in captive and wild Diamond Firetails. We found that spot number was significantly repeatable in captive birds. Larger females and spottier females in both the wild and in captivity laid larger clutches, and spottier captive birds built nests with longer tunnels. Using clay eggs in artificial nests with manipulated tunnel lengths in the wild, we found that nests with longer tunnels were less likely to be depredated, particularly by birds. These results suggest that nest morphology may function as an extended phenotype related to female ornamentation, both of which can signal female quality and/or investment, and may be selected for through both sexual and natural selection.
The replacement of native temperate forests by exotic tree plantations is widespread in southern South America, yet its functional consequences for forest birds remain insufficiently understood. Because population density alone may not reliably indicate habitat quality, we evaluated whether substitution by mature Pinus radiata plantations alters foraging niche attributes of forest birds in south-central Chile. We compared bird densities, microhabitat use, foraging manoeuvres, and multidimensional niche overlap between native forest fragments and adjacent pine plantations during breeding and non-breeding seasons. Bird densities were generally lower in pine plantations, and several forest specialists were absent from this habitat. Mean foraging height showed no consistent habitat effect once species identity and temporal variation were accounted for. However, plantations were characterised by reduced foliage volume in lower strata, and foraging observations were disproportionately associated with native understory vegetation within plantations. For focal species with sufficient observations, multidimensional niche analyses revealed habitat-specific shifts in microhabitat use and, for one species pair, greater convergence in niche space in plantations relative to native forests. These patterns were accompanied by changes in the frequency of certain foraging manoeuvres. Our results indicate that habitat substitution by pine plantations modifies microhabitat use and niche relationships among forest birds, consistent with reduced structural complexity relative to native forests. Although some species exhibited behavioural flexibility, plantations did not support the full assemblage of forest specialists. Integrating behavioural niche attributes with density measures provides an informative assessment of habitat substitution effects in temperate Neotropical forest landscapes.
The Eyrean Grasswren is a little-known passerine of the Simpson and Strzelecki Deserts in central Australia thought to be dependent on sandhill canegrass (Zygochloa paradoxa). However, no formal habitat studies on the species have been conducted. We investigated habitat associations of Eyrean Grasswrens at Ethabuka Reserve, on the northern edge of the species' range, using transect surveys (n = 53, covering 106 km) with call playback to record occurrence, coupled with systematic vegetation sampling. We analysed results using three approaches: (1) testing occurrence in relation to canegrass presence/absence; (2) modelling the effects of canegrass characteristics (cover, density); and (3) modelling the influence of sand dune vegetation structure (tree density, shrub density, dune height, vegetation cover). We also assessed how past fire events and dune height shaped these habitat features. Grasswrens were found exclusively on dunes with sandhill canegrass, favouring sparse, large tussocks over dense clusters of smaller plants. They occurred on dunes with greater plant diversity and low tree density. Dune height influenced vegetation cover and tree density, while a higher proportion of long unburnt dune increased vegetation diversity which impacted grasswren occurrence. These findings indicate that canegrass structure, vegetation diversity, and fire history all play a role in determining grasswren habitat suitability. The preference for widely spaced mature tussocks likely reflects the feeding, movement and breeding requirements of grasswrens. Our results emphasise the importance of maintaining plant diversity and managing fire in landscapes that contain large sandhill canegrass tussocks to preserve unburnt refuges for Eyrean Grasswrens.
Tropical seabirds often forage facultatively in association with tuna and may be affected by industrial fisheries both directly through bycatch, and indirectly through reduced prey availability following tuna removal. We tracked seven Juan Fern & aacute;ndez Petrels Pterodroma externa - endemic to the Juan Fern & aacute;ndez Islands, Chile, and among the most abundant seabirds in the eastern tropical Pacific - using geolocator-immersion loggers over 2 years (2020-2022) to examine migratory routes, year-round distributions, activity patterns and overlap with fisheries. During pre-laying exodus and incubation, birds occupied subtropical and sub-Antarctic waters in the southeast Pacific, reaching 5,781 and 4,298 km from the colony, respectively. During the non-breeding period, birds dispersed widely across the eastern and central Pacific, from Peru to Mexico and as far north as Hawaii. Individuals showed annual consistency in migration strategies but did not aggregate in a single region, with 3-8 residency periods each lasting 15-80 days. Return migrations followed looping routes through the South Pacific, likely assisted by mid-latitude westerly winds. At-sea flight activity was lower during non-breeding (45% time flying) than breeding (73-77%) and increased around the full moon, both by night (by 20%) and day (51%), suggesting lunar effects on prey availability and nocturnal foraging, and potential diurnal compensation. Although our sample was small, there was substantial overlap between non-breeding distributions and industrial tuna longline and purse-seine fisheries. These results provide the first description of their annual movements and highlight potential fisheries exposure, laying groundwork for future studies to quantify population-level distributions and the dynamics of seabird-fisheries interactions.
Parrots across the globe are at risk from habitat removal and modification. The Vulnerable Eastern Ground Parrot Pezoporus wallicus of Australia is subject to anthropogenic influences and monitoring is paramount for its protection. Pezoporus wallicus is shy and rarely seen, but it calls predictably and distinctively. Autonomous Recording Units were used to record the diel patterns of calling behaviour and investigate the detectability of P. wallicus during a breeding season, to derive optimal sampling methods. Recorders were deployed within heathlands in south-east Queensland during 2020, recording for 60 minutes around civil dawn and dusk. Call rates across recording periods were generally higher in the evening (27.8 calls per site) than morning (7.4 calls per site). Most calling occurred over half hour periods, with peaks at civil dawn and dusk. Daily calling was variable within and across sites. Occupancy modelling indicated a minimum survey effort of four evening acoustic survey sessions per site over four days if manually searching for calls on spectrograms or 3 days, if call recognisers could be utilised, would maximise the likelihood of a 95% probability of detecting P. wallicus at an occupied site. Efficient surveys using ARU technology will be of great benefit to monitoring this and other declining bird species around the world.
The introduction of Mallards (Anas platyrhynchos) into New Zealand (NZ) established a self-sustaining feral population, with many hybrids arising through ongoing interbreeding with endemic Grey Ducks (Anas superciliosa superciliosa; P & amacr;rera). We investigated whether NZ Mallards and verified contemporary P & amacr;rera x NZ Mallard hybrids exhibit hybrid vigour by comparing morphometrics (body mass, wing chord and culmen length) and viability metrics (fecundity and nest success) against P & amacr;rera. P & amacr;rera were generally smaller than NZ Mallards, while hybrids were intermediate, with backcrossed individuals tending towards the size of their respective parent species. Importantly, a binomial generalised linear model of daily nest survival revealed that hybrid females outperform NZ Mallards, with female age, body size and condition also significantly influencing survival. Despite clear morphological differences among genetic groups, these results indicate that hybrids gain a measurable advantage in nest viability. Given that NZ Mallards and contemporary hybrids are at least as viable as P & amacr;rera, and that hybrids show higher daily nest survival than Mallards, our findings are consistent with expectations of hybrid heterosis. In the Anthropocene, understanding the adaptive potential of hybrids is critical as anthropogenic hybridisation rises. For P & amacr;rera, hybridisation with Mallards represents one of the multiple existential threats, alongside habitat loss, overharvest and exotic predators. However, the elevated survival of hybrid populations suggests that if P & amacr;rera were lost, hybrids could successfully occupy their ecological niche, with implications for conservation management of endemic waterfowl.
Keeping alien birds in Australia poses a significant environmental and agricultural biosecurity risk if birds escape or are released from captivity. Red whiskered Bulbuls were introduced to Australia in 1865 and have subsequently become established in the wild in New South Wales and Victoria, but are not established in South Australia, where they are a declared pest bird. Between 1993 and 2018, 19 birds were found and removed from the wild or captivity in the Adelaide Hills and Adelaide suburbs, South Australia. We used mitochondrial DNA sequences and nuclear single-nucleotide polymorphisms (SNPs) to examine the geographical origin of these red-whiskered bulbuls in South Australia, the minimum number of birds that were introduced, and the relationship within and between the captive and wild birds. We found two mitochondrial DNA haplotypes, suggesting a minimum of two females were introduced into South Australia. Nuclear SNPs revealed two main clusters of individuals: (1) all 7 wild Adelaide Hills birds, and (2) all 11 captive birds plus one wild Adelaide suburbs bird, suggesting two separate origins. Wild birds were first- or second-degree relatives, indicating that this was a breeding population, but they were not derived from the captive Adelaide population. None of the captive birds were closely related, suggesting that captive birds were not yet a breeding colony and had been sourced from unrelated individuals, probably in eastern Australia. Our results show that molecular methods are a valuable tool in the biosecurity innovation suite for understanding the provenance of escaped biosecurity risk species.
Within the Indo-Pacific, understory birds have received the majority of phylogeographic investigation while canopy birds are comparatively under-studied. The White-bellied Cuckooshrike (Coracina papuensis), generally considered a canopy species, contains 13-15 described taxa but lacks a modern genomic dataset corroborating these distinctions. Therefore, we evaluated the phylogeography of C. papuensis using genome-wide single nucleotide polymorphisms for 49 individuals representing the taxa with available tissue samples (10 of the 13-15). We identified varying support for eight different lineages with limited diversification across the Australian continental shelf but surprisingly we found support for two lineages in eastern Papua New Guinea (Central and Oro Provinces) and evidence of long-distance dispersal.
Migratory shorebird populations are declining primarily because of intertidal habitat loss. Conservation efforts rely on monitoring, but ground surveys are generally impractical on extensive mudflats where shorebirds forage. On the 12th of March 2024, we used a DJI Mavic 3 Enterprise to conduct a proof-of-concept drone survey of shorebirds foraging on a 650 m x 250 m section of intertidal mudflat within Moreton Bay, Australia (GPS: -27.51, 153.41). We surveyed seven 16 m wide transects, spaced 75 m apart, across the mudflat perpendicular to the tidal front. We generated image mosaics for each transect and used manual and computer vision methods to locate and identify the birds. We also conducted concurrent ground counts and monitored for disturbance. Drone surveys detected 77 waterbirds, while ground counts recorded 46 birds, including 31 waterbirds, 2 seabirds, 12 non-migratory shorebirds, and 1 migratory shorebird. Differences in counts were attributed to excessive spacing between transects. We recommend that surveys: (1) use sensors capable of 0.5 cm pix-1 resolution and a large image footprint from above the flight initiation distance of sensitive species; (2) use multiple batteries and drones if needed; (3) use a transect-based flight path oriented perpendicular to the tidal front with transects spaced using conservative abundance estimates; (4) acquire approval to fly beyond visual line of sight and above 120 m if necessary; (5) ensure compatibility between flight application, camera, and flight plan; (6) consider processing images individually rather than as orthomosaics; (7) use computer vision tools for large sites or aggregations.
Dispersal is a critical yet challenging life-history stage for wildlife, with successful dispersal essential for gene flow, population connectivity, and mitigation of local extinctions. However, the behavioural transition from natal dependency to independence - a key preparatory stage known as natal prospecting - is poorly known. These knowledge gaps are especially pronounced in large, elusive, and nocturnal species, such as Powerful Owls (Ninox strenua). Here, we utilise GPS tracking data collected across 48 nights to investigate the fine-scale spatial and movement behaviours during a juvenile Powerful Owl's post-fledgling period, characterising natal prospecting in Victoria, Australia, providing novel insights into a rarely observed ecological process. The juvenile exhibited clear temporal changes in movement behaviour during the post-fledgling phase. Over time, movements became increasingly exploratory, with the individual travelling longer distances and exhibiting reduced spatial overlap between successive nights. Our findings suggest a progressive expansion of the juvenile's familiarity with the landscape via exploratory forays, potentially in preparation for dispersal. These behaviours likely facilitate assessment of habitat suitability and inform the selection of transient dispersal routes. As such, maintaining and restoring forested habitat and ecological corridors is critical to supporting these essential preparatory movements. This study highlights the value of GPS telemetry in understanding natal prospecting behaviours in a threatened apex predator. Expanded investigation across diverse landscape contexts will be essential for informing evidence-based habitat management and conservation planning.
The South Island K & omacr;kako (Callaeas cinerea) is an endemic New Zealand bird species with an uncertain extinction status. Declared extinct in 2007, the species was re-evaluated as extant in 2013, following a single verified sighting. There have been no verified sightings in the years since, but large numbers of unverified sightings. In this paper, we apply statistical methods to this sighting timeseries to evaluate whether a population of the species continues to exist on the South Island and Stewart Island. Our findings suggest that there is still a reasonable probability (48%) that the species is still extant. However, we also find that it is not improbable that all recent sightings are false positives. These results raise important questions about the reliability of current extinction models in the presence of nonstationary sighting processes, and their implications for the allocation of sparse conservation funding.
