Using a common commensal bacterium in endangered Takahe as a model to explore pathogen dynamics in isolated wildlife populations

Predicting and preventing outbreaks of infectious disease in endangered wildlife is problematic without an understanding of the biotic and abiotic factors that influence pathogen transmission and the genetic variation of microorganisms within and between these highly modified host communities. We used a common commensal bacterium, Campylobacter spp., in endangered Takahe (Porphyrio hochstetteri) populations to develop a model with which to study pathogen dynamics in isolated wildlife populations connected through ongoing translocations. Takahe are endemic to New Zealand, where their total population is approximately 230 individuals. Takahe were translocated from a single remnant wild population to multiple offshore and mainland reserves. Several fragmented subpopulations are maintained and connected through regular translocations. We tested 118 Takahe from 8 locations for fecal Campylobacter spp. via culture and DNA extraction and used PCR for species assignment. Factors relating to population connectivity and host life history were explored using multivariate analytical methods to determine associations between host variables and bacterial prevalence. The apparent prevalence of Campylobacter spp. in Takahe was 99%, one of the highest reported in avian populations. Variation in prevalence was evident among Campylobacter species identified. C. sp. nova 1 (90%) colonized the majority of Takahe tested. Prevalence of C. jejuni (38%) and C. coli (24%) was different between Takahe subpopulations, and this difference was associated with factors related to population management, captivity, rearing environment, and the presence of agricultural practices in the location in which birds were sampled. Modeling results of Campylobacter spp. in Takahe metapopulations suggest that anthropogenic management of endangered species within altered environments may have unforeseen effects on microbial exposure, carriage, and disease risk. Translocation of wildlife between locations could have unpredictable consequences including the spread of novel microbes between isolated populations.     

Economic Valuation of Subsistence Harvest of Wildlife in Madagascar

Wildlife consumption can be viewed as an ecosystem provisioning service (the production of a material good through ecological functioning) because of wildlife's ability to persist under sustainable levels of harvest. We used the case of wildlife harvest and consumption in northeastern Madagascar to identify the distribution of these services to local households and communities to further our understanding of local reliance on natural resources. We inferred these benefits from demand curves built with data on wildlife sales transactions. On average, the value of wildlife provisioning represented 57% of annual household cash income in local communities from the Makira Natural Park and Masoala National Park, and harvested areas produced an economic return of U.S.$0.42 ha^?1· year^?1. Variability in value of harvested wildlife was high among communities and households with an approximate 2 orders of magnitude difference in the proportional value of wildlife to household income. The imputed price of harvested wildlife and its consumption were strongly associated (p< 0.001), and increases in price led to reduced harvest for consumption. Heightened monitoring and enforcement of hunting could increase the costs of harvesting and thus elevate the price and reduce consumption of wildlife. Increased enforcement would therefore be beneficial to biodiversity conservation but could limit local people's food supply. Specifically, our results provide an estimate of the cost of offsetting economic losses to local populations from the enforcement of conservation policies. By explicitly estimating the welfare effects of consumed wildlife, our results may inform targeted interventions by public health and development specialists as they allocate sparse funds to support regions, households, or individuals most vulnerable to changes in access to wildlife. Valoración Económica de la Caza de Subsistencia de Vida Silvestre en Madagascar     

Association of reproductive traits with captive- versus wild-sourced birds in trade

The wildlife trade is a billion-dollar global business, involving millions of people, thousands of species, and hundreds of millions of individual organisms. Unravelling whether trade targets reproductively distinct species and whether this preference varies between captive- and wild-sourced species is a crucial question. We used a comprehensive list of all bird species traded, trade listings and records kept in compliance with the Convention on International Trade in Endangered Species (CITES), and a suite of avian reproductive parameters to examine whether wildlife trade is associated with particular facets of life history and to examine the association between life-history traits and captive- and wild-sourced traded volumes over time. Across all trade, CITES listing, and CITES trade, large birds were more likely to be traded and listed, but their longevity and age at maturity were not associated with CITES listing or trade. We found species across almost the full range of trait values in both captive and wild trade between 2000 and 2020. Captive trade volumes clearly associated with relatively longer lived and early-maturing species; these associations remained stable and largely unchanged over time. Trait–volume associations in wild-sourced trade were more uncertain. Only body mass had a clear association, and it varied from negative to positive over time. Although reproductive traits were important in captive-sourced trade, species-level variation dominated trade, with even congeneric species varying greatly in volume despite similar traits. The collection and incorporation of trait data into sustainability assessments of captive breeding facilities are crucial to ensure accurate quotas and guard against laundering.     

Mapping Hotspots of Threatened Species Traded in Bushmeat Markets in the Cross–Sanaga Rivers Region

Bushmeat markets exist in many countries in West and Central Africa, and data on species sold can be used to detect patterns of wildlife trade in a region. We surveyed 89 markets within the Cross–Sanaga rivers region, West Africa. In each market, we counted the number of carcasses of each taxon sold. During a 6‐month period (7594 market days), 44 mammal species were traded. Thirteen species were on the International Union for Conservation of Nature (IUCN) Red List or protected under national legislation, and at least 1 threatened species was traded in 88 of the 89 markets. We used these data to identify market groups that traded similar species assemblages. Using cluster analyses, we detected 8 market groups that were also geographically distinct. Market groups differed in the diversity of species, evenness of species, and dominant, prevalent, and characteristic species traded. We mapped the distribution of number of threatened species traded across the study region. Most threatened species were sold in markets nearest 2 national parks, Korup National Park in Cameroon and Cross River in Nigeria. To assess whether the threatened‐species trade hotspots coincided with the known ranges of these species, we mapped the overlap of all threatened species traded. Markets selling more threatened species overlapped with those regions that had higher numbers of these. Our study can provide wildlife managers in the region with better tools to discern zones within which to focus policing efforts and reduce threats to species that are threatened by the bushmeat trade. Mapeo de Sitios Críticos para Especies Amenazadas Comercializadas en Mercados de Vida Silvestre en la Región de los Ríos Cross‐Sanaga     

Use of DNA barcoding to reveal species composition of convenience seafood

Increased education of consumers can be an effective tool for conservation of commercially harvested marine species when product labeling is accurate and allows an informed choice. However, generic labeling (e.g., as white fish or surimi) and mislabeling of seafood prevents this and may erode consumer confidence in seafood product labels in general. We used DNA barcoding to identify the species composition of two types of convenience seafood (i.e., products processed for ease of consumption): fish fingers (long pieces of fish covered with bread crumbs or batter, n = 241) and seafood sticks (long pieces of cooked fish, n = 30). In products labeled as either white fish or surimi, four teleost species were present. Less than 1.5% of fish fingers with species-specific information were mislabeled. Results of other studies show substantially more mislabeling (e.g., >25%) of teleost products, which likely reflects the lower economic gains associated with mislabeling of convenience seafood compared with whole fillets. In addition to species identification, seafood product labels should be required to contain information about, for example, harvesting practices, and our data indicate that consumers can have reasonable confidence in the accuracy of the labels of convenience seafood and thus select brands on the basis of information about current fisheries practice.     

Social and Ecological Change over a Decade in a Village Hunting System,Central Gabon

Despite widespread recognition of the major threat to tropical forest biological diversity and local food security posed by unsustainable bushmeat hunting, virtually no long‐term studies tracking the socioecological dynamics of hunting systems have been conducted. We interviewed local hunters and collected detailed hunting data to investigate changes in offtake and hunter characteristics over 10 years (2001–2010) in Dibouka and Kouagna villages, central Gabon, in the context of hunter recollections of longer term trends since the 1950s. To control for changes in hunter behavior, such as trap location and characteristics, we report hunting offtake data per trap. Our results suggest the hunting area was already highly depleted by 2001; local hunters reported that 16 large‐bodied prey species had become rare or locally extirpated over the last 60 years. Overall, we observed no significant declines in hunting offtake or changes in species composition from 2001 to 2010, and offtakes per trap increased slightly between 2004 and 2010. However, trapping distance from the villages increased, and there was a switch in hunting techniques; a larger proportion of the catch was hunted with guns in 2010. The number of hunters declined by 20% from 2004 to 2010, and male livelihood activities shifted away from hunting. Hunters with the lowest hunting incomes in 2004 were more likely than successful hunters to have moved away from the village by 2010 (often in response to alternative employment opportunities). Therefore, changes in trap success (potentially related to biological factors) were interacting with system‐level changes in hunter number and composition (related to external socioeconomic factors) to produce a relatively static overall offtake. Our results highlight the importance of understanding the small‐scale context of hunting to correctly interpret changes or apparent stasis in hunting effort and offtake over time. Cambio Social y Ecológico a lo Largo de Una Década en un Sistema de Cacería Aldeana, Gabón Central     

Effects of Road Mortality and Mitigation Measures on Amphibian Populations

Road mortality is a widely recognized but rarely quantified threat to the viability of amphibian populations. The global extent of the problem is substantial and factors affecting the number of animals killed on highways include life‐history traits and landscape features. Secondary effects include genetic isolation due to roads acting as barriers to migration. Long‐term effects of roads on population dynamics are often severe and mitigation methods include volunteer rescues and under‐road tunnels. Despite the development of methods that reduce road kill in specific locations, especially under‐road tunnels and culverts, there is scant evidence that such measures will protect populations over the long term. There also seems little likelihood that funding will be forthcoming to ameliorate the problem at the scale necessary to prevent further population declines. Efectos de la Mortalidad en Carreteras y Medidas de Mitigación en Poblaciones de Anfibios Beebee     

Demographic Connectivity for Ursid Populations at Wildlife Crossing Structures in Banff National Park

Wildlife crossing structures are one solution to mitigating the fragmentation of wildlife populations caused by roads, but their effectiveness in providing connectivity has only been superficially evaluated. Hundreds of grizzly (Ursus arctos) and black bear (Ursus americanus) passages through under and overpasses have been recorded in Banff National Park, Alberta, Canada. However, the ability of crossing structures to allow individual and population‐level movements across road networks remains unknown. In April 2006, we initiated a 3‐year investigation into whether crossing structures provide demographic connectivity for grizzly and black bears in Banff National Park. We collected hair with multiple noninvasive methods to obtain genetic samples from grizzly and black bears around the Bow Valley. Our objectives were to determine the number of male and female grizzly and black bears that use crossing structures; examine spatial and temporal patterns of crossings; and estimate the proportions of grizzly and black bear populations in the Bow Valley that use crossing structures. Fifteen grizzly (7 female, 8 male) and 17 black bears (8 female, 9 male) used wildlife crossing structures. The number of individuals detected at wildlife crossing structures was highly correlated with the number of passages in space and time. Grizzly bears used open crossing structures (e.g., overpasses) more often than constricted crossings (e.g., culverts). Peak use of crossing structures for both bear species occurred in July, when high rates of foraging activity coincide with mating season. We compared the number of bears that used crossings with estimates of population abundance from a related study and determined that substantial percentages of grizzly (15.0% in 2006, 19.8% in 2008) and black bear (17.6% in 2006, 11.0% in 2008) populations used crossing structures. On the basis of our results, we concluded wildlife crossing structures provide demographic connectivity for bear populations in Banff National Park. Conectividad Demográfica para Poblaciones de Úrsidos en Estructuras para Cruce de Vida Silvestre en el Parque Nacional Banff     

Species composition of the international shark fin trade assessed through a retail‐market survey in Hong Kong

The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species‐specific basis. Species‐specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999–2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014–2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one‐third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1–64.2% for blue [Prionace glauca], 0.2–1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals.     

Effects of uncertainty and variability on population declines and IUCN Red List classifications

The International Union for Conservation of Nature (IUCN) Red List Categories and Criteria is a quantitative framework for classifying species according to extinction risk. Population models may be used to estimate extinction risk or population declines. Uncertainty and variability arise in threat classifications through measurement and process error in empirical data and uncertainty in the models used to estimate extinction risk and population declines. Furthermore, species traits are known to affect extinction risk. We investigated the effects of measurement and process error, model type, population growth rate, and age at first reproduction on the reliability of risk classifications based on projected population declines on IUCN Red List classifications. We used an age‐structured population model to simulate true population trajectories with different growth rates, reproductive ages and levels of variation, and subjected them to measurement error. We evaluated the ability of scalar and matrix models parameterized with these simulated time series to accurately capture the IUCN Red List classification generated with true population declines. Under all levels of measurement error tested and low process error, classifications were reasonably accurate; scalar and matrix models yielded roughly the same rate of misclassifications, but the distribution of errors differed; matrix models led to greater overestimation of extinction risk than underestimations; process error tended to contribute to misclassifications to a greater extent than measurement error; and more misclassifications occurred for fast, rather than slow, life histories. These results indicate that classifications of highly threatened taxa (i.e., taxa with low growth rates) under criterion A are more likely to be reliable than for less threatened taxa when assessed with population models. Greater scrutiny needs to be placed on data used to parameterize population models for species with high growth rates, particularly when available evidence indicates a potential transition to higher risk categories.