Population genomics and structure of the critically endangered Mariana Crow (Corvus kubaryi)

Funding: UK Biotechnology and Biological Sciences Research Council (BBSRC) David Phillips Fellowship (BB/G023913/2) (C.R.).The Mariana Crow, or Åga (Corvus kubaryi), is a critically endangered species (IUCN - International Union for Conservation of Nature), endemic to the islands of Guam and Rota in the Mariana Archipelago. It is locally extinct on Guam, and numbers have declined dramatically on Rota to a historical low of less than 55 breeding pairs throughout the island in 2013. Because of its extirpation on Guam and population decline on Rota, it is of critical importance to assess the genetic variation among individuals to assist ongoing recovery efforts. We conducted a population genomics analysis comparing the Guam and Rota populations and studied the genetic structure of Rota individuals population. We used blood samples from five birds from Guam and 78 birds from Rota. We identified 145,552 candidate single nucleotide variants (SNVs) from a genome sequence of an individual from Rota and selected a subset of these to develop an oligonucleotide in-solution capture assay. The Guam and Rota populations were genetically differentiated from each other. Crow populations sampled broadly across their range on Rota showed significant genetic structuring – a surprising result given the small size of this island and the good flight capabilities of the species. Knowledge of its genetic structure will help improve management policies strategies to help with its recovery.Publisher PDFPeer reviewe

Nest predation in some Australian forest, woodland and shoreline-breeding birds

Abstract not availabl

Nest predation in some Australian forest, woodland and shoreline-breeding birds

Abstract not availabl

Key demographic factors for recovery of the endangered Nightingale Reed-Warbler (Acrocephalus hiwae) via population viability analysis

The Nightingale Reed-Warbler (Acrocephalus hiwae), a critically endangered songbird, is the last remaining of four reed-warbler species that once inhabited the Mariana Islands. The most recent population estimate for the species is 2915-3742 individuals distributed over the islands of Saipan (n = 2742, 95% CI = 1686-3956) and Alamagan (n = 946, 95% CI = 173-1000), which represents a significant decline for the species on Saipan. Though data on life history parameters such as survival rates are not widely available, other parameters such as clutch size and nest success have been studied. Given the extirpation of three of the four reed-warbler species from the Mariana Islands, the recent significant decline of the larger Saipan population, and the increasing threats faced by the species, it is critical to determine what additional life history information is needed to aid management decisions. Using Vortex, we developed stochastic population models to represent current reed-warbler population dynamics and used sensitivity analysis to identify the life history parameters to which the model was most sensitive. Baseline models without inbreeding indicated declines of the Nightingale Reed-Warbler populations on Saipan and Alamagan, as well as of the overall population. The inclusion of inbreeding further increases the modeled rate of population decline. Parameters such as initial population size, carrying capacity, and male survival have relatively little influence on reed-warbler population models, while female and juvenile survival and, to a lesser degree, fecundity measures, exhibit strong influences on the species' population dynamics. We recommend effort be placed on collecting updated survival data for all life stages, but particularly for females and juveniles. Given model predictions of vulnerability to extinction, we recommend management actions that may increase survival rates of juveniles and females

2019 Kiwikiu Conservation Translocation Report

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.The U.S. Fish & Wildlife Service (USFWS) Recovery Plan for the kiwikiu (Maui Parrotbill; Pseudonestor xanthophrys) (USFWS 2006) recommended establishing a second population within its historical range to protect the species from catastrophic loss in its small current range. In addition to the inherent threats of a small population and small range size, the current kiwikiu population is located on the windward (northeastern) slope of Haleakalā where they are under threat from severe weather events and frequent rainfall that have been shown to reduce reproductive success. The Kahikinui region of Maui on the leeward (southern) slope of Haleakalā was selected as the site of a new population of kiwikiu. Nakula Natural Area Reserve (NAR) was selected as the first release site to begin establishing the species in the Kahikinui region. The Maui Forest Bird Working Group (MFBWG; hereafter “the working group”) wrote a comprehensive Kiwikiu Reintroduction Plan (MFBWG 2018). After many years of preparation, which included building infrastructure, controlling predators, and reducing mosquito densities in Nakula NAR, 14 kiwikiu were transferred to the site: seven wild birds translocated from Hanawī NAR and seven from a conservation breeding facility managed by San Diego Zoo Global. The birds from the conservation breeding facility and the wild were moved to Nakula NAR in mid-October 2019 and releases were completed a few weeks later. After release, birds were monitored using radio telemetry through November 2019 at which point all birds either had died or disappeared (except for one individual that was transferred back to the conservation breeding facility). Necropsies indicated avian malaria as the primary cause of death for all recovered individuals and little hope remains for the few remaining missing birds at the site. Unexpectedly high densities of mosquitoes were later confirmed within the release site. Further investigation revealed that the translocated wild individuals tested positive for the malaria parasite prior to the move to Nakula NAR. In this report, we discuss the strategies that were employed during the kiwikiu translocation, the outcome of those actions, and the steps moving forward for both future release improvements and recovery strategies for the kiwikiu

Evaluation of replicate sampling using hierarchical spatial modeling of population surveys accounting for imperfect detectability

Abstract Effective species management and conservation benefit from knowledge of species distribution and status. Surveys to obtain that information often involve replicate sampling, which increases survey effort and costs. We simultaneously modeled species distribution, abundance and spatial correlation, and compared the uncertainty in replicate abundance estimates of the endangered palila (Loxioides bailleui) using hierarchical generalized additive models with a soap film smoother that incorporated random effects for visit. Based on survey coverage and detections, we selected the 2017 point‐transect distance sampling survey on Mauna Kea, Hawai‘i Island, for our modeling. Our modeling approach allowed us to account for imperfect detections, control the effects of boundary features, and generate visit‐specific density surface maps. We found that visit‐specific smooths were nearly identical, indicating that little information was gained from a subsequent visit, and that most of the estimator uncertainty was derived from within‐visit variability. Scaling back the palila survey to a single visit would halve the survey effort and logistical costs and increase efficiencies in data management and processing. Changing the sampling protocol warrants careful consideration and our findings may help management and regulatory agencies by maximizing efficiency and minimizing costs of surveying protocols, while providing guidelines on how to best collect information critical to species' conservation