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Genetics is a fast‐moving field, and for conservation practitioners or ecologists, it can be bewildering. The choice of marker used in studies is fundamental; in the literature, preference has recently shifted from microsatellites to single nucleotide polymorphism (SNP) loci. Understanding how marker type affects estimates of population genetic parameters is important in the context of conservation, especially because the accuracy of estimates has a bearing on the actions taken to protect threatened species. We compare parameter estimates between seven microsatellites, 3761 SNP loci, and a random subset of 100 SNPs for the exact same 324 individual swift parrots, Lathamus discolor, and also use 457 additional samples from subsequent years to compare SNP estimates. Both marker types estimated a lower HO than HE. We show that microsatellites and SNPs mainly indicate a lack of spatial genetic structure, except when a priori collection locations were used on the SNP data in a discriminant analysis of principal components (DAPC). The 100‐SNP subset gave comparable results to when the full dataset was used. Estimates of effective population size (Ne) were comparable between markers when the same individuals were considered, but SNPs had narrower confidence intervals. This is reassuring because conservation assessments that rely on population genetic estimates based on a few microsatellites are unlikely to be nullified by the general shift toward SNPs in the literature. However, estimates between markers and datasets varied considerably when only adult samples were considered; hence, including samples of all age groups is recommended to be used when available. The estimated Ne was higher for the full SNP dataset (2010–2019) than the smaller comparison data (2010–2015), which might be a better reflection of the species status. The lower precision of microsatellites may not necessarily be a barrier for most conservation applications; however, SNPs will improve confidence limits, which may be useful for practitioners. [ABSTRACT FROM AUTHOR]

Abstract Genetics is a fast‐moving field, and for conservation practitioners or ecologists, it can be bewildering. The choice of marker used in studies is fundamental; in the literature, preference has recently shifted from microsatellites to single nucleotide polymorphism (SNP) loci. Understanding how marker type affects estimates of population genetic parameters is important in the context of conservation, especially because the accuracy of estimates has a bearing on the actions taken to protect threatened species. We compare parameter estimates between seven microsatellites, 3761 SNP loci, and a random subset of 100 SNPs for the exact same 324 individual swift parrots, Lathamus discolor, and also use 457 additional samples from subsequent years to compare SNP estimates. Both marker types estimated a lower HO than HE. We show that microsatellites and SNPs mainly indicate a lack of spatial genetic structure, except when a priori collection locations were used on the SNP data in a discriminant analysis of principal components (DAPC). The 100‐SNP subset gave comparable results to when the full dataset was used. Estimates of effective population size (Ne) were comparable between markers when the same individuals were considered, but SNPs had narrower confidence intervals. This is reassuring because conservation assessments that rely on population genetic estimates based on a few microsatellites are unlikely to be nullified by the general shift toward SNPs in the literature. However, estimates between markers and datasets varied considerably when only adult samples were considered; hence, including samples of all age groups is recommended to be used when available. The estimated Ne was higher for the full SNP dataset (2010–2019) than the smaller comparison data (2010–2015), which might be a better reflection of the species status. The lower precision of microsatellites may not necessarily be a barrier for most conservation applications; however, SNPs will improve confidence limits, which may be useful for practitioners.

Conservation assessments of threatened species are often limited by scarce data and parameter uncertainty. Predictive models, designed to incorporate this uncertainty, may be the only tool available to inform conservation assessments for data‐deficient species, but they are used surprisingly rarely for this purpose. The swift parrot Lathamus discolor is the only critically endangered bird to be listed in Australia based on population viability analysis (PVA). We aimed to evaluate the accuracy of the 2015 conservation assessment, which used sparse information, by incorporating new detailed and long‐term data. First, we updated a range of life history parameter estimates, and then we repeated the same PVA as per the original conservation assessment. This process confirmed our earlier finding that swift parrot nests were more likely to survive in places with high mature forest cover. We identify that high forest landscape integrity and abundant hollow‐bearing trees best predict nest daily survival rates. Based on the updated PVA, we predict a 92.3% population decline over three generations (11 years). This supported the predictions of the original conservation assessment, and the main benefit of the additional data was improved confidence in projections (the magnitude and direction of the population decline were similar between the original and updated PVAs). Our results demonstrate that meaningful trends can be inferred for species with imperfect information about their life history. Using predictive models like PVAs can help managers identify which life history parameters impact most on demographic trends. This information can guide targeted data collection so that 'draft' models can be later updated to improve certainty around population predictions. [ABSTRACT FROM AUTHOR]

Life history theory predicts that long‐lived animals trade off the costs of reproduction against individual survival. If the costs of reproduction are too high, animals should prioritize their own survival. During bad times, mobile animals may be able to compensate for local food shortages by travelling further to provision their offspring. But, whether inherent mobility alleviates individual fitness costs of this parental strategy is not known. We studied parental investment and breeding success of long‐lived, nomadic, migratory swift parrots Lathamus discolor over two successive years at the same site where food abundance went from locally low to high. We hypothesize that in a bad year, swift parrots should adjust their parental strategy by foregoing breeding altogether, producing smaller clutches/broods or reducing provisioning investment. Fewer swift parrots bred locally when food was scarce. In the bad year, clutch and brood sizes were smaller and nestlings were >20 g lighter (approximately 28% of mean body mass) than in the good year. Compared with the good year, fathers spent longer foraging, less time at the nest and travelled further during provisioning trips in the bad year. Although limited to only 2 years, our results suggest that mobile species may attempt to mitigate the effects of a bad year on their reproductive success by rearing fewer offspring and investing more in provisioning behaviour, but this strategy may not necessarily compensate for environmental conditions. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Nomadic species are globally threatened by anthropogenic habitat change, but management options to address their decline are limited. Their unpredictable settlement patterns pose major challenges for conservation because identifying where to implement action is difficult. We address this challenge by pre‐empting settlement patterns in a nomadic species using data from a long‐term study of the critically endangered, cavity‐nesting swift parrot (Lathamus discolor) and by taking action at the sites identified. We detected flower bud growth (the primary settlement cue) and deployed artificial nests at 3 predicted breeding sites before the birds arrived. At the broad breeding‐range scale, swift parrots settled wherever bud abundance was highest, including the study area. Within the study area, artificial nest occupancy was greatest at the site with abundant historical natural nesting sites. At the local scale, we found significant effects of study site and distance to forest edges on nest box occupancy by swift parrots. Despite significant differences in thermal properties between artificial and natural nests, we found no differences in clutch size, brood size, or body condition of swift parrots in each. Monitoring settlement patterns and future food availability of nomadic wildlife can empower conservation managers to make predictions about breeding and target ecologically relevant times and locations when deploying conservation resources. Our study is an example of how conservation challenges posed by nomadic species can be overcome, and demonstrates that with effective monitoring, practical action can be targeted to address acute conservation needs and augment habitat availability. © 2018 The Wildlife Society. By monitoring food availability and nest site use of nomadic animals at broad scales, we show it is possible to predict where to deploy conservation resources. We deployed nest boxes to increase the availability of habitat based on predicted settlement, which provided additional habitat of comparable quality to natural nesting sites for a critically endangered nomadic bird. [ABSTRACT FROM AUTHOR]

Abstract: 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. [ABSTRACT FROM AUTHOR]

The distribution of mobile species in dynamic systems can vary greatly over time and space. Estimating their population size and geographic range can be problematic and affect the accuracy of conservation assessments. Scarce data on mobile species and the resources they need can also limit the type of analytical approaches available to derive such estimates. We quantified change in availability and use of key ecological resources required for breeding for a critically endangered nomadic habitat specialist, the Swift Parrot ( Lathamus discolor). We compared estimates of occupied habitat derived from dynamic presence-background (i.e., presence-only data) climatic models with estimates derived from dynamic occupancy models that included a direct measure of food availability. We then compared estimates that incorporate fine-resolution spatial data on the availability of key ecological resources (i.e., functional habitats) with more common approaches that focus on broader climatic suitability or vegetation cover (due to the absence of fine-resolution data). The occupancy models produced significantly ( P < 0.001) smaller (up to an order of magnitude) and more spatially discrete estimates of the total occupied area than climate-based models. The spatial location and extent of the total area occupied with the occupancy models was highly variable between years (131 and 1498 km2). Estimates accounting for the area of functional habitats were significantly smaller (2-58% [SD 16]) than estimates based only on the total area occupied. An increase or decrease in the area of one functional habitat (foraging or nesting) did not necessarily correspond to an increase or decrease in the other. Thus, an increase in the extent of occupied area may not equate to improved habitat quality or function. We argue these patterns are typical for mobile resource specialists but often go unnoticed because of limited data over relevant spatial and temporal scales and lack of spatial data on the availability of key resources. Understanding changes in the relative availability of functional habitats is crucial to informing conservation planning and accurately assessing extinction risk for mobile resource specialists. [ABSTRACT FROM AUTHOR]

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 processes that potentially limit populations across multiple scales. Fine-scale cavity characteristics have important consequences for predator exclusion and fecundity, while broad-scale processes (food or habitat availability) can determine population viability. We considered the relative importance of cavity morphology in limiting the breeding success of a critically endangered secondary cavity nesting bird that is severely affected at broad scales by nest predation. Swift Parrots (Lathamus discolor) select nest cavities where the minimum entrance diameter is positively associated with cavity depth, floor diameter and maximum entrance diameter. These cavity characteristics are adaptive because they exclude native predators by physically preventing access to the nest chamber; only one introduced nest predator is able to overcome this passive nest defence. Introduced Sugar Gliders (Petaurus breviceps) could prey on Swift Parrot nests irrespective of nest cavity morphology. We found no effect of cavity morphology on the number of eggs laid or fledglings reared by Swift Parrots. This suggests that fine-scale nest cavity characteristics do not influence the nest success of Swift Parrots beyond their effectiveness in excluding native Tasmanian predators. [ABSTRACT FROM AUTHOR]

Numerous pollinators are declining across the world. One o f these, the swift parrot (Lathamus discolor) is a critically endangered Australian bird that feeds largely on the nectar and pollen o f Eucalyptus trees. The Swift Parrot Recovery Plan includes competition for food from introduced social bees as a threatening process, although little evidence exists in support o f this. Here, we present the strongest evidence yet to support this theory. We examined nectar standing crops in the species o f trees that are important to swift parrots during their breeding season, Tasmanian blue gum (Eucalyptus globulus) and black gum (E. ovata). By comparing the amounts o f nectar between flowers exposed to visitors and those bagged to exclude visitors throughout the day, we discovered that introduced honey bees (Apis mellifera) and bumble bees (Bombus terrestris) consumed most o f the nectar and that exposed flowers often contained little nectar. Honey bees were the more common species, but bumble bees had greater per capita rates o f nectar consumption. However, at low densities these bees had no effect on standing crops of nectar, and in such situations some nectar could be harvested by managed honey bees without reducing nectar availability for swift parrots. Although this study suggests that introduced social bees may pose a threat to swift parrots, further work is needed to determine whether our results are indicative o f the impacts o f bees across greater scales o f time and space and whether these affect the reproductive success and conservation status o f the swift parrot. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

A female swift parrot (Lathamus discolour) sits at the entrance of her nest hollow in old growth Eucalyptus forest. Introduced predators are killing large numbers of nesting females leading to male‐biased sex ratios, increased competition among males for mates, and unusually high rates of shared paternity. (See pp. 502–510). Photo by Dejan Stojanovic. [ABSTRACT FROM AUTHOR]

Assessing future changes in the suitability of the climate niche for interacting species across different trophic levels can identify direct and indirect effects of climate change that may be missed using single-species approaches. We use ensembles of species distribution models based on a dynamically down-scaled regional climate model to project the future suitability of climate for the Swift Parrot (Lathamus discolor), its primary food and habitat resources (Tasmanian Blue Gum (Eucalyptus globulus) and Swamp Gum (E. ovata)), and an introduced nest predator, the Sugar Glider (Petaurus breviceps). These results are combined with layers representing mature forest and fire danger to identify locations that may act as refuges for the Swift Parrot from fire, deforestation and predation under baseline and future climates. Almost a quarter of the nesting habitat of Swift Parrots is projected to become climatically unsuitable by the end of the 21st century, but large areas may remain climatically suitable for both Swift Parrots and their food trees. However, loss of forests and the presence of Sugar Gliders are likely to limit the availability of high-quality habitat. Offshore islands that the Sugar Glider is unable to colonise or where future climate is not projected to be suitable for the Sugar Glider may be the only places, in the near future, where the Swift Parrot will be protected from nest predation by this introduced species. [ABSTRACT FROM AUTHOR]

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., 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., 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., 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., 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The article focuses on Swift Parrot, Lathamus discolor, which is a Tasmanian migratory species, listed as an endangered species by the Tasmanian government. It describes analysis of conservation law and policy that is applied for strengthening legislation and regulations in conserving the Swift Parrot habitat. It mentions the effect of the Environment Protection and Biodiversity Conservation Act of 1999 and the Threatened Species Protection Act 1995 in preserving the endangered species.

Most cavity-dependent species select tree-cavities with a narrow range of characteristics so that only a small subset of available cavities may be suitable for any species. Most surveys for tree-cavities are done from the ground using binoculars to reduce effort, but this technique is prone to error. These errors are likely to contribute to the loss of the cavity resource when used to inform conservation efforts for cavity-dependent species. The Swift Parrot (Lathamus discolor) is an endangered migratory bird threatened by ongoing removal of cavity-bearing trees by production forestry. We climbed trees with cavities used for nesting by Swift Parrots and determined that they prefer cavities with small entrances, deep chambers and wide floors. Such cavities are rare and occur in large trees that support higher than average numbers of tree-cavities. Importantly, cavities used by Swift Parrots were also likely to be both overestimated and underestimated using ground-based surveys, and without calibration by climbing, the size and direction of survey error could not be determined. We conclude that the most effective way to gain detailed information about the characteristics and abundance of tree-cavities is to climb a representative sample of trees to calibrate ground-based methods for a specific ecosystem. [ABSTRACT FROM AUTHOR]

Declines in avian biodiversity are being reported worldwide. A better understanding of the ecology of many species is fundamental to identifying and addressing threatening processes and developing effective mitigation measures. The Swift Parrot (Lathamus discolor) is listed as endangered and is an obligate migrant that breeds only in Tasmania, wintering in mainland Australia. The species nests in tree-hollows and forages primarily on flowers of the Tasmanian Blue Gum (Eucalyptus globulus) and Black Gum (Eucalyptus ovata) during the breeding season. Surveys for Swift Parrot nests conducted over three consecutive breeding seasons identified 130 Swift Parrot nests in 117 trees. Sites were between 12 and 130 ha in area with up to 49 nests found at an individual site. Swift Parrot nest-trees were characterised as being large eucalypts (mean diameter at breast height = 105 cm) with five or more potential hollows (mean = 8.6) and showing clear signs of senescence. Reuse of nests was uncommon over the 3 years and the infrequency of reuse was most likely related to poor flowering of Tasmanian Blue Gums around nesting sites in years following recorded nesting. To protect the species, conservation actions need to account for the spatiotemporal variation in the availability of Swift Parrot breeding habitat and recognise there may be several years between the use of a particular site. Given the number of nests found at individual sites this will require the management or reservation of suitable forest stands with old-growth characteristics across the landscape, rather than focussing on individual trees or historical nesting sites. [ABSTRACT FROM AUTHOR]

The synchronisation of metabolism and behaviour to support migration has been demonstrated in a wide range of migratory organisms. However these models have been developed using long-distance migrants. This study investigated physiological and behavioural changes associated with short-distance migration in Swift Parrots (Lathamus discolor). Non-migratory Musk Lorikeets (Glossopsitta concinna) were included as a comparator species. The mean body mass and fat score of wild Swift Parrots was higher in spring than in summer. Mean pectoral muscle condition score did not vary seasonally. There was no significant variation in plasma corticosterone concentration in either captive adult male Swift Parrots or captive Musk Lorikeets, when examined either by month or when pooled by season. Captive Swift Parrots showed inconsistent diurnal and nocturnal orientation preferences. There was no evidence of migratory restlessness in any of the periods examined. Pectoral muscle condition, plasma corticosterone concentrations and behavioural changes of migratory restlessness and orientation showed no clear seasonal pattern of synchronous change that is expected in a migratory species. This may reflect the weakly synchronised migration of the Swift Parrots or that the fairly short-distance migration requires minimal physiological preparation. [ABSTRACT FROM AUTHOR]

The endangered Swift Parrot Lathamus discolor breeds mostly in coastal south-eastern Tasmania, an area where urban development is common and the city of Hobart is situated. Hobart's suburbs are visited regularly by foraging Swift Parrots that nest in the surrounding forests. The reproductive success of Swift Parrots depends largely on the availability of the birds' major dietary items, the nectar and pollen of Eucalyptus trees. This study investigated the relative value of suburban trees and those in adjacent native forest in Hobart as food sources for Swift Parrots. To this end, we compared flower production between mature trees in suburban and bushland areas for the two species on which Swift Parrots predominantly forage while breeding; Tasmanian Blue Gum Eucalyptus globulus and Black Gum E. ovata. For both species, flower production over the past few years was greater for individual trees in the suburb than for those in the surrounding bushland. Hence, individual trees in the suburb probably provide more nectar and pollen than do those in the nearby bushland and are potentially important to the reproductive success of Swift Parrots. Our findings suggest that the relatively poor flowering in this peri-urban bushland may be the result of poorer health of trees in the bushland than in the suburb, particularly the greater fire damage and sparser canopies in the bushland trees. Further research is required to determine the frequency and intensity of fire in bushland that will promote the greatest flower production in E. globulus and E. ovata. [ABSTRACT FROM AUTHOR]

Abstract: It is becoming increasingly easy to generate genotypic data but much harder to gather an equivalent amount of phenotypic information, particularly for chemical traits. In this study of Eucalyptus globulus ssp. globulus, we measured about 60 chemical leaf traits of trees growing in a common garden to address the following questions: (1) how much variation is there between geographic regions, populations within regions and within populations? (2) How do chemical traits vary over the species’ geographic range? (3) If so, does E. globulus ssp. globulus exhibit distinct chemotypes – plants that are morphologically similar but which differ chemically? (4) Are the affinities between E. globulus ssp. globulus and closely related subspecies apparent in the chemical variation? Variation among trees within populations contributed most variation in leaf chemistry followed by variation between geographic regions. For many traits, variation among populations within proposed races and variation among proposed races within geographic regions explained little of the total variation. There was a cline in the concentration of secondary chemicals with the lowest concentrations in Tasmanian populations and the highest in those from eastern Victoria, with intermediate concentrations in populations from Bass Strait Islands. We identified three chemotypes, characterised by specific terpenes and formylated phloroglucinol compounds. The frequency of occurrence of these chemotypes showed a geographic pattern also, with “chemotype 1” predominating in Tasmania, while “chemotypes 2 and 3” occurred at highest frequency in eastern Victoria. We suggest that the chemotypes reflect introgression between E. globulus ssp. globulus and the three closely related subspecies –E. globulus ssp. bicostata, E. globulus ssp. maidenii and E. globulus ssp. pseudoglobulus. Although the formation of land-bridges with fluctuating sea levels has no doubt shaped the evolutionary history of all four subspecies, we propose that the migratory swift parrot (Lathamus discolor), an important pollinator and a species closely associated with E. globulus, has helped shape the evolution of the four tree subspecies. [Copyright &y& Elsevier]

Migratory birds are dependent on a combination of suitable wintering, migration and breeding habitats. Identification and protection of these habitats is essential for the conservation of the birds. The endangered Swift Parrot (Psittacidae:Lathamus discolor) migrates north from Tasmania to south-eastern mainland Australia in search of suitable winter food resources. This 5-year study examines the use of known winter foraging habitats by Swift Parrots on a state-wide scale not previously attempted. Swift Parrots used a diversity of winter foraging habitats in regions of the coast and western slopes of New South Wales each year, including several habitats that occur in endangered ecological communities. The abundance of Swift Parrots in New South Wales fluctuated significantly between years and regions, with coastal areas providing important drought-refuge habitats for a large proportion of the population. Over half of all foraging sites were used repeatedly, highlighting their likely importance for conservation. Landscapes containing winter foraging habitat included scattered trees, remnant vegetation and continuous forests, and Swift Parrots foraged extensively on lerp and nectar from a diversity of tree species within these. The occurrence of Swift Parrots at foraging sites was primarily associated with the abundance of lerp, nectar and non-aggressive competitors. [ABSTRACT FROM AUTHOR]

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.