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A complete species census and evidence for regional declines in piping plovers

Complete population estimates for widely distributed species are rarely possible. However, for the third time in 10 years, an International Piping Plover ( Charadrius melodus ) Breeding and Winter Census was conducted throughout the species range in 2001. Nearly 1,400 participants from 32 U.S. states and Puerto Rico; 9 Canadian provinces; St. Pierre and Miquelon, France; Cuba; and the Bahamas visited 2,244 sites covering 11,836 km of shoreline habitat. During the winter census, 2,389 piping plovers were observed at 33.5% of potentially occupied sites ( n = 352). Of these, 56.8% had ≤ 10 birds present. The breeding census recorded 5,945 adults at 777 of 1,892 sites surveyed. More than 80% of sites with piping plovers present had ≤ 10 birds. Results indicated an 8.4% increase from 1991 but only a 0.2% increase since 1996. Regional trends suggest that since 1991, number of breeding birds increased on the Atlantic Coast by 78% (2,920 birds; 12.4% increase since 1996) and by 80% in the Great Lakes (72 birds; 50% increase since 1996). However, plovers declined 15% (2,953 birds; 10% decline since 1996) in Prairie Canada/U.S. northern Great Plains. Subregional trends since 1991 reflect a 32.4% decline in Prairie Canada (972 birds; 42.4% decline since 1996), a 2.5% decline in the U.S. northern Great Plains (1,981 birds; 24% increase since 1996), 5.5% decline in eastern Canada (481 birds; 14% increase since 1996), although a 66.2% increase on the U.S. Atlantic Coast (2,430 birds; 12% since 1996). While numbers were down in much of the U.S. northern Great Plains since 1996, an increase (460%, 1,048 birds; 67.7% increase since 1991) was detected on the Missouri River. Results from 3 complete species census efforts provide essential data for conservation planning and assessment and illustrate the utility of global censuses for species of concern.

Journal of Wildlife Management

Community-based conservation and recovery of native species on Monuriki Island, Fiji

The small uninhabited island of Monuriki (40.4 ha) in western Fiji is of national and international conservation concern for its several protected species. Exotic invasive species and a Category 5 cyclone have exacerbated conservation challenges. The cooperation of local, national, and international stakeholders continues to be crucial in restoration of the island’s native flora and fauna. This summary presents a timeline of restoration efforts and current status of the recovery programme for Monuriki. The critically endangered dry forest habitat of Fiji is only found in a few isolated patches on disparate islands. The Fijian crested iguana (Brachylophus cf. vitiensis) is a critically endangered species restricted to a few small islands in this dry forest zone of western Fiji. The population of crested iguanas on Monuriki Island is the third largest remaining population. Even before iguanas were first documented on the island in the early 1980s, individuals had been removed by local resorts for display purposes, a practice that was previously unregulated. In the late 1990s, the first efforts to conserve and restore Monuriki Island were discussed, but conservation initiatives were not implemented until the development of the Crested Iguana Recovery Plan in 2008. In 2011, domestic goats (Capra hircus) and non-native rats (Rattus exulans) were removed from the island, and 10 pairs of iguanas were brought into captive breeding facilities within Fiji. In 2015, the first 32 captive-bred crested iguanas were released back on Monuriki Island. More than half of these iguanas (N=26) were radio-tracked for 56 days post-release in order to assess survivorship and help provide insights into their short-term movement patterns. Of the 26 iguanas that were tracked, nearly 70% (N=18) were found after 56 days indicating excellent short-term survival. In February 2016, Tropical Cyclone Winston, a Category 5 storm passed through Fiji and devastated some of the tropical dry forest habitat on Monuriki. With sustained winds of up to 230 km/ hr nearly all of the canopy leaves from trees on Monuriki Island were removed and large amounts of debris covered the forest floor. Following the cyclone, a brief wildlife survey revealed Monuriki’s iguana and bird populations were still present. In 2017, the crested iguana captive breeding programme was brought to an end when 16 of the original 20 iguana founders, and an additional 32 captive bred off spring, were reintroduced onto Monuriki. This was accomplished, in part, due to successful breeding and reestablishment of the remaining wild iguanas on the island. Despite a major storm event, reestablishment likely resulted from reduced egg and hatchling predation by the rats, and excellent habitat recovery after goat removal. Overall these invasive species eradications have proven highly successful for the recovery of the iguanas, wedge-tailed shearwaters (Puffi nus pacifi cus), and several other non-target species including the banded rail (Gallirallus philippensis) and endangered Fijian peregrine falcon (Falco peregrinus). Furthermore, eradication of non-native species has also helped the recovery of the highly threatened tropical dry forest ecosystem in which these species exist.

Monuriki island

Estimating migratory game-bird productivity by integrating age ratio and banding data

Context: Reproduction is a critical component of fitness, and understanding factors that influence temporal and spatial dynamics in reproductive output is important for effective management and conservation. Although several indices of reproductive output for wide-ranging species, such as migratory birds, exist, there has been no theoretical justification for their estimators or associated measures of variance. Aims: The aims of our research were to develop statistical justification for an estimator of reproduction and associated variances on the basis of an existing national wing-collection survey and banding data, and to demonstrate the applicability of this estimator to a migratory game bird. Methods: We used a Bayesian hierarchical modelling approach to integrate wing-collection data, which provides information on population age ratios, and band-recovery data, which provides information on recovery probabilities of various age classes, for American woodcock ( Scolopax minor ) to estimate productivity and associated measures of variance. We present two models of relative vulnerability between age classes: one model assumed that adult recovery probabilities were higher, but that annual fluctuations were synchronous between the two age classes (i.e. an additive effect of age and year). The second model assumed that adults, on average, had higher recovery probabilities than did juveniles and that annual fluctuations were asynchronous through time (i.e. an interaction between age and year). Key results: Fitting our models within a hierarchical Bayesian framework efficiently incorporates the two data types into a single estimator and derives appropriate variances for the productivity estimator. Further, use of Bayesian methods enabled us to derive credible intervals that avoid the reliance on asymptotic assumptions. When applied to American woodcock data, the additive model resulted in biologically realistic and more precise age-ratio estimates each year and is adequate when the relative vulnerability to sampling only slightly varies or does not vary among components of a population (e.g. age, sex class) among years. Therefore, we recommend using woodcock indices from our analysis based on this model. Conclusions: We provide a flexible modelling framework for estimating productivity and associated variances that can incorporate ecological covariates to explore various factors that could drive annual dynamics in productivity. Applying our model to the American woodcock data indicated that assumptions about the variability in relative recovery probabilities could greatly influence the precision of our productivity estimator. Therefore, researchers should carefully consider the assumption of temporally variable relative recovery probabilities (i.e. ratio of juvenile to adults' recovery probability) for different age classes when applying this estimator. Implications: Several national and international management strategies for migratory game birds in North America rely on measures of productivity from harvest survey parts collections, without a justification of the estimator or providing estimates of precision. We derive an estimator of productivity with realistic measures of uncertainty that can be directly incorporated into management plans or ecological studies across large spatial scales.

Wildlife Research