Identifying conservation units after large-scale land clearing: a spatio-temporal molecular survey of endangered white-tailed black cockatoos (Calyptorhynchus spp.)

Aim: We examined how the threatened and endemic white-tailed black cockatoos of Western Australia have responded genetically to recent and comprehensive habitat loss with the ultimate aim of identifying units for conservation. We assessed the population structure, connectivity and genetic diversity at spatial and temporal scales for Calyptorhynchus baudinii and C. latirostris, which have undergone dramatic population declines. Genetic comparisons of pre- and post-population decline were carried out by including historical samples dating back to 1920. We examined samples collected from across 700 km of their distribution and sampled approximately 1% of the current population census size to produce significant insights into the population genetics of white-tailed black cockatoos and generate genetic information crucial for conservation management. Location: Southwest corner of Western Australia. Methods: Six hundred and eighty-four cockatoo samples were collected from 1920 to 2010 and profiled with 19 microsatellites to identify spatial population structure and loss of genetic diversity.Results: The temporal and spatial microsatellite data illustrated that the geographically defined genetic structuring in white-tailed black cockatoos is likely to represent a recent phenomenon. We identified: (1) spatial population substructure east and west of extensively cleared habitat (>95,800 km2), but the historical samples clustered with the current western population, regardless of origin, (2) a regional loss of allelic diversity over 3–4 generations for the current eastern population, (3) a lack of a genetic signal of the recent population decline, but perhaps a mid-Holocene population collapse and lastly, (4) limited genetic differentiation between the two currently recognized white-tailed black-cockatoo species suggests a review of taxonomy and/or management units should be undertaken. Main conclusion: Based on extensive spatio-temporal sampling, we have demonstrated that recent anthropogenic habitat modifications have affected the genetic structure of a long-lived and highly mobile species. Our results have identified areas of high conservation value and the importance of maintaining native vegetation migration corridors

Validation of the use of firearms for euthanising stranded cetaceans

Efforts to euthanise stranded cetaceans remain highly variable in their outcomes, with few field tested operational procedures available. This study sought to validate the efficacy of using modern firearms technology to euthanise small (<6m length) stranded cetaceans. Post-mortem evidence was gathered from the standardised shooting of cetacean cadavers (n = 10), representing six species, using .30 caliber (7.62mm) firearms and blunt solid copper-alloy non-deforming projectiles, in southwestern Australia. The six species studied were Risso's dolphin, common dolphin, bottlenosed dolphin, pygmy sperm whale, Cuvier's beaked whale, and humpback whale. Post-mortem data revealed that 100% of bullet wound tracts fully penetrated the skulls of shot animals, with associated indirect skull fracturing, secondary bone missiles and brain parenchyma laceration. The results suggest that appropriate firearms technology is fully capable of inducing instantaneous fatal pathology to the central nervous system of these species. In comparison to alternative methods for the euthanasia of stranded cetaceans, the use of firearms is associated with superior animal welfare outcomes, public safety levels and accessibility. This paper provides a template for the safe, humane and repeatable use of this technique to euthanise <6m length stranded cetaceans

Characterisation and cross-species utility of 20 microsatellite markers for population and forensic applications in the endangered Carnaby’s Black-cockatoo, Calyptorhynchus latirostris

We characterise 20 microsatellite loci identified from the endangered Carnaby’s Black-cockatoo (Calyptorhynchus latirostris). The primers were tested across 40 individuals from the southwest of Western Australia and displayed between 4 and 11 alleles per locus with expected heterozygosities ranging from 53 to 87% and exclusion probabilities of C0.999. These loci will be useful in population genetic studies to facilitate conservation management decisions in addition to wildlife enforcement applications for the endangered Carnaby’s Black-cockatoo. We also tested the markers in 12 high profile and smuggled species from five genera, Cacatua, Callocephalon, Calyptorhynchus, Nymphicus and Probosciger. These species detected between 2 and 19 alleles per locus with 50–100% amplification success

Measuring the Welfare Impact of Soft-Catch Leg-Hold Trapping for Feral Cats on Non-Target By-Catch

To inform trapping protocols to reduce by-catch while trapping feral cats by-catch welfare costs should be quantified. During cat trapping programs at six Western Australian sites from 1997–2015, 431 non-target individuals, including 232 individuals from native species (132 mammals, 52 birds and 42 reptiles) were captured. Among the native fauna; birds were more likely to be severely injured (33%, compared to 12% in mammals and 21% in reptiles). Amongst other vertebrates, larger individuals were less likely to be injured. Olfactory lures used in these studies attracted reptiles, but repelled mammals. By-catch varied with climate and landscape. Trap injury to by-catch species poses ethical concerns, especially for threatened species that can least afford an additional threat. Future trapping should consider the timing of trapping, trap placement, trap settings (especially the treadle pressure needed to close the trap) and new innovations sending immediate capture alerts to minimise by-catch and potential injury associated with prolonged restraint. By-catch welfare data should be analysed to identify best practice and on-going improvement

The evolutionary history of cockatoos (Aves: Psittaciformes: Cacatuidae)

Cockatoos are the distinctive family Cacatuidae, a major lineage of the order of parrots (Psittaciformes) and distributed throughout the Australasian region of the world. However, the evolutionary history of cockatoos is not well understood. We investigated the phylogeny of cockatoos based on three mitochondrial and three nuclear DNA genes obtained from 16 of 21 species of Cacatuidae. In addition, five novel mitochondrial genomes were used to estimate time of divergence and our estimates indicate Cacatuidae diverged from Psittacidae approximately 40.7. million years ago (95% CI 51.6-30.3. Ma) during the Eocene. Our data shows Cacatuidae began to diversify approximately 27.9. Ma (95% CI 38.1-18.3. Ma) during the Oligocene. The early to middle Miocene (20-10. Ma) was a significant period in the evolution of modern Australian environments and vegetation, in which a transformation from mainly mesic to xeric habitats (e.g., fire-adapted sclerophyll vegetation and grasslands) occurred. We hypothesize that this environmental transformation was a driving force behind the diversification of cockatoos. A detailed multi-locus molecular phylogeny enabled us to resolve the phylogenetic placements of the Palm Cockatoo (Probosciger aterrimus), Galah (Eolophus roseicapillus), Gang-gang Cockatoo (Callocephalon fimbriatum) and Cockatiel (Nymphicus hollandicus), which have historically been difficult to place within Cacatuidae. When the molecular evidence is analysed in concert with morphology, it is clear that many of the cockatoo species' diagnostic phenotypic traits such as plumage colour, body size, wing shape and bill morphology have evolved in parallel or convergently across lineages

Survival and reintegration of rehabilitated Carnaby’s Cockatoos Zanda latirostris into wild flocks

Release into the wild is the preferred outcome for rehabilitated animals, but often little is known about what happens to individuals following their release. Increased knowledge of post-release survival and reintegration into the wild could improve release and rehabilitation strategies. To assess the survival and reintegration of rehabilitated Endangered Carnaby’s Cockatoos Zanda latirostris into wild flocks we studied the movements and behaviour of 23 birds fitted with satellite tracking devices. We assessed longer term survival by collating records of leg-banded birds over eight years. Rehabilitated birds had an estimated annual survival rate of 0.73. The band recovery rate for all rehabilitated Carnaby’s Cockatoos banded between 2005 and 2013 was not significantly different to those fitted with tracking devices (10.3% versus 13.0% respectively, P = 1). Physical, social and behavioural indicators of fitness were used to assess the success of the reintegration of rehabilitated birds. Released birds flew, roosted and foraged with wild birds. Whilst pair bond formation and breeding of study birds could not be confirmed during this study, behaviours associated with pair bonding were observed, including allo-preening and male courtship displays. The rehabilitation process and pre-release procedure for identifying individuals ready for release was effective at selecting suitable release candidates

Subsidized commercial harvesting for cost-effective wildlife management in urban areas: A case study with kangaroo sharpshooting

The management of overabundant urban fauna is a contentious issue worldwide, particularly for populations of white-tailed deer (Odocoileus virginianus) in North America and kangaroos (Macropus spp.) in Australia. To be successful, management programs in such settings must be cost-effective, humane, and publicly acceptable. Here, we describe the management of a fenced, urban population of western grey kangaroos (M. fuliginosus) in southwestern Australia, with an estimated population density of 189 kangaroos/km2. After a period of >12 months of solicited public involvement by key stakeholder groups, a licensed professional shooting team, observing a national code of practice, conducted night-time sharpshooting. Over an 11-month period in 2006–2007, 1,009 kangaroos were shot in 43 shooting nights, a mean (±SE) culling rate of 23 ± 3 kangaroos/night or harvest rate of 12 ± 2 kangaroos/hr. Inspectors under the relevant Western Australian legislation functioned as animal welfare observers to ensure that the methods employed for the culling program met the national code of practice and that all license conditions were met. No accidents or injuries occurred during the program. The program produced 17 kg/kangaroo of harvestable meat and biological samples for several research projects. The operational costs of the project were very low, at AU$36/kangaroo, with payments largely limited to incentives paid to commercial harvesters and management staff monitoring public safety and animal welfare. This case study is an example of a publicly acceptable, cost-effective, humane, and lethal urban wildlife control operation. It demonstrates that public acceptance of a cull of wildlife can be forthcoming with appropriate prior consultation and high professional standards

Costs are key when reintroducing threatened species to multiple release sites

Threatened species with reduced and fragmented habitats can be reintroduced into their historical ranges to establish new populations. Multiple sites might be an option for reintroductions; therefore, managers must determine when to open sites (e.g. establish infrastructure and improve conditions), release individuals into those sites, and eventually cease releases. Careful planning of this schedule, incorporating the cost of actions, is imperative at the outset of a program. To address this challenge, we consider a reintroduction plan under different cost scenarios for three potential reintroduction sites. In particular, we investigate the implications of having either no ongoing site-management cost, a financial ongoing site-management cost, or a demographic cost of continuous releases. We couple population and management models to find a schedule that maximizes total abundance over time of bridled nail-tail wallaby Onychogalea fraenata (released in fixed numbers each breeding season from a stable source population) using stochastic dynamic programming. We find that the type of ongoing cost influences the structure of the optimal schedule. If active release sites cost nothing to maintain, there is no incentive to cease releases. In that case, the optimal schedule is to open sites sequentially, then release individuals to the smallest active population for the entire length of the program. A financial cost for managing active sites alters this result; once all sites are open and have populations of a critical threshold size, sites should be closed sequentially. A higher mortality rate (demographic cost) at active compared to inactive sites completely changes the structure of the optimal strategy. Instead of opening all sites in the first few management stages, only one site should be active any time to reduce the demographic impact of releases. Our general results provide a guide for planning future reintroduction programs and illustrate the importance of categorizing and understanding ongoing costs for reintroduction planning

Regional variation in habitat matrix determines movement metrics in Baudin

Context: The Baudin’s cockatoo is one of three black cockatoo species endemic to Western Australia and is listed as Endangered by state and federal governments. Although there is a Recovery Plan in place for this species, conservation efforts are hindered by gaps in knowledge regarding the species movement ecology. Aims: To identify key foraging and roosting habitat for Baudin’s cockatoos and to determine differences in flock movements, including the spatial extent of movement, in Urban, Peri-urban and Forest regions using telemetry data. Methods: Wild Baudin’s cockatoos that had been injured and undergone rehabilitation were equipped with satellite PTT (platform transmitter terminal) and GPS tags and released back into wild flocks. The study birds, and the flocks into which they integrated, were tracked in the field to collect telemetry and observational data. Satellite data were used to define the types of movement behaviour (resident, ranging, migratory), and GPS data were analysed to determine key foraging and roosting habitat, and to calculate home range area estimates. Key results: There was a significant difference in flock movement between the Urban/Peri-urban regions and the Forest region in terms of daily distances moved and distances between roosts, with these parameters being far greater for the Forest region. Additionally, flock sizes were larger in the Forest region compared with the Urban and Peri-urban regions. In Urban and Peri-urban regions, key habitat comprised remnant vegetation in urban green space (nature reserves, parks and private property), and roadside and riparian vegetation, which served as movement corridors in the landscape. Conclusions: The research shows that it is important to maintain vegetation connectivity in the landscape. This enables Baudin’s cockatoos to utilise key patches of remnant vegetation in their non-breeding wintering grounds in Urban and Peri-urban regions of the Perth Peel Coastal Plain. Further research on the movement ecology of Baudin’s cockatoos should focus on habitat suitability modelling, which, in combination with the identified key habitat sites, will benefit the decision-making process in relation to conservation management of this endangered black cockatoo species. Implications: This research has benefited the conservation management of Baudin’s cockatoos by providing information on key habitat through satellite tracking and outlining the importance of the connective features of remnant vegetation. We advocate for further telemetry studies combined with habitat suitability modelling to preserve the necessary habitat for the persistence of this species in the Western Australian landscape