Comparing environmental influences on coral bleaching across and within species using clustered binomial regression

Differential susceptibility among reef-building coral species can lead to community shifts and loss of diversity as a result of temperature-induced mass bleaching events. We evaluate environmental influences on coral colony bleaching over an 8-year period in the Florida Keys, USA. Clustered binomial regression is used to develop models incorporating taxon-specific responses to the environment in order to identify conditions and species for which bleaching is likely to be severe. By building three separate models incorporating environment, community composition, and taxon-specific responses to environment, we show observed prevalence of bleaching reflects an interaction between community composition and local environmental conditions. Environmental variables, including elevated sea temperature, solar radiation, and reef depth, explained 90% and 78% of variability in colony bleaching across space and time, respectively. The effects of environmental variables were only partially explained (33% of variability) by corresponding differences in community composition. Taxon-specific models indicated individual coral species responded differently to local environmental conditions and had different sensitivities to temperature-induced bleaching. For many coral species, but not all, bleaching was exacerbated by high solar radiation. A 25% reduction in the probability of bleaching in shallow locations for one species may reflect an ability to acclimatize to local conditions. Overall, model results indicate predictions of coral bleaching require knowledge of not just the environmental conditions or community composition, but the responses of individual species to the environment. Model development provides a useful tool for coral reef management by quantifying the influence of the local environment on individual species bleaching sensitivities, identifying susceptible species, and predicting the likelihood of mass bleaching events with changing environmental conditions.     

Urban land use predicts West Nile virus exposure in songbirds

Urbanization is a widespread phenomenon that is likely to influence the prevalence and impact of wildlife pathogens, with implications for wildlife management and public health policies toward zoonotic pathogens. In this study, wild songbird populations were sampled at 14 sites along an urban rural gradient in the greater metropolitan Atlanta (Georgia, USA) area and tested for antibodies to West Nile virus (WNV). The level of urbanization among sites was quantitatively assessed using a principal component analysis of key land use characteristics. In total, 499 individual birds were tested during the spring and summer over three years (2004-2006). Antibody prevalence of WNV increased from rural to urban sites, and this trend was stronger among adult birds relative to juveniles. Furthermore, antibody prevalence among Northern Cardinals (Cardinalis cardinalis) was significantly higher than in other songbird species along the urban gradient. Findings reported here indicate that ecological factors associated with urbanization can influence infection patterns of this vector-borne viral disease, with likely mechanisms including changes in host species diversity and the tolerance or recovery of infected animals.     

Metacommunity models predict the local-regional species richness relationship in a natural system

Many natural communities exhibit positive relationships between local and regional species richness (LSR-RSR relationships), which can be either linear or curvilinear. Previous models have shown that the form of this relationship depends on the relative rates of colonization and extinction and the sensitivity of these rates to competition. We use simple models to show that the LSR-RSR relationship also depends on the type of metacommunity structure (Levins-like or mainland-island), and our models generate a wider range of realistic forms than do most previous models. We parameterize and test our models with two independent data sets for Daphnia in rock pools on islands in Finland and Sweden. We find that the Levins-like model with competition correctly predicts the observed LSR-RSR relationship and provides the best fit to the average local species richness per island. Simulations show that our models are robust to relaxing our assumption of identical species properties. Our study is one of the first to make and successfully test quantitative predictions for how a widely studied community pattern, the LSR-RSR relationship, arises from metacommunity dynamics.     

Voice as Entry to Agriculturalists’ Conservationist Identity: A Cultural Inventory of the Yellowstone River

We explored the communicative construction of a conservationist identity among primary producers by excavating voices of agriculturalists operating along the Yellowstone River (Montana, USA). We used a cultural inventory approach to discover and then listen to informants’ voices as they constructed their conservation identity. Those who self-identified as conservationists talked about their ecological and social responsibilities, and described challenges they faced in protecting individual resources and system processes of the watershed. For these agriculturalists, conservation and production are inextricably linked, and enable them to provide a sustainable resource base for future generations. Insight from these voices enhances understanding of what sustainability could mean to those who self-identify as both conservationists and primary producers.     

Challenges in modeling detailed and complex environmental data sets: a case study modeling the excess partial pressure of fluvial $$\hbox {CO}_2$$ CO 2

Environmental and Ecological Statistics - Advances in sensor technology enable environmental monitoring programmes to record and store measurements at a high temporal resolution, enhancing the...     

Integrating archaeology and ancient DNA analysis to address invasive species colonization in the Gulf of Alaska

The intentional and unintentional movement of plants and animals by humans has transformed ecosystems and landscapes globally. Assessing when and how a species was introduced are central to managing these transformed landscapes, particularly in island environments. In the Gulf of Alaska, there is considerable interest in the history of mammal introductions and rehabilitating Gulf of Alaska island environments by eradicating mammals classified as invasive species. The Arctic ground squirrel (Urocitellus parryii) is of concern because it affects vegetation and seabirds on Gulf of Alaska islands. This animal is assumed to have been introduced by historic settlers; however, ground squirrel remains in the prehistoric archaeological record of Chirikof Island, Alaska, challenge this timeline and suggest they colonized the islands long ago. We used 3 lines of evidence to address this problem: direct radiocarbon dating of archaeological squirrel remains; evidence of prehistoric human use of squirrels; and ancient DNA analysis of dated squirrel remains. Chirikof squirrels dated to at least 2000 years ago, and cut marks on squirrel bones suggested prehistoric use by people. Ancient squirrels also shared a mitochondrial haplotype with modern Chirikof squirrels. These results suggest that squirrels have been on Chirikof longer than previously assumed and that the current population of squirrels is closely related to the ancient population. Thus, it appears ground squirrels are not a recent, human‐mediated introduction and may have colonized the island via a natural dispersal event or an ancient human translocation.     

Near-miss events,risk messages,and decision making

Decades of research have sought to understand how disaster preparedness decisions are made. We believe one understudied factor is the impact of near-miss events. A near-miss occurs when an event (such as a hurricane or terrorist attack) has some non-trivial probability of ending in disaster (loss of life, property damage), but the negative outcome is avoided largely by chance (e.g., at the last minute, the storm dissipates or the bomb fails to detonate). In the first of two experiments, we study reactions to a hurricane threat when participants are told about prior near-miss events. We find that people with information about a prior near-miss event that has no negative consequences are less likely to take protective measures than those with either no information or information about a prior near-miss event that has salient negative information. Similar results have been shown in prior research, but we seek to understand people’s reasoning for the different reactions. We examine the role of an individual’s risk propensity and general level of optimism as possible explanatory variables for the “near-miss” effect. We find risk propensity to be stable across conditions, whereas general optimism is influenced by the type of prior near-miss information, so that optimism mediates how near-miss information impacts protective decisions. People who experience a potentially hazardous near-miss but escape without obvious cues of damage will feel more optimistic and take less protective action. In the second study, we test messages about the hazard’s risk and examine the impact of these messages to offset the influence of near-misses. We end by discussing the implications of near-misses for risk communication.     

Understanding public perceptions of risk regarding outdoor pet cats to inform conservation action

Free‐ranging domestic cats (Felis catus) incur and impose risks on ecosystems and represent a complex issue of critical importance to biodiversity conservation and cat and human health globally. Prior social science research on this topic is limited and has emphasized feral cats even though owned cats often comprise a large proportion of the outdoor cat population, particularly in urban areas. To address this gap, we examined public risk perceptions and attitudes toward outdoor pet cats across varying levels of urbanization, including along the wildland–urban interface, in Colorado (U.S.A.), through a mail survey of 1397 residents. Residents did not view all types of risks uniformly. They viewed risks of cat predation on wildlife and carnivore predation on cats as more likely than disease‐related risks. Additionally, risk perceptions were related to attitudes, prior experiences with cats and cat–wildlife interactions, and cat‐owner behavior. Our findings suggest that changes in risk perceptions may result in behavior change. Therefore, knowledge of cat‐related risk perceptions and attitudes could be used to develop communication programs aimed at promoting risk‐aversive behaviors among cat owners and cat‐management strategies that are acceptable to the public and that directly advance the conservation of native species.