Influence of Care of Domestic Carnivores on Their Predation on Vertebrates

Abstract: Domestic dogs (Canis familiaris) and cats (Felis catus) are the most abundant mammalian carnivores worldwide. Given that domestic carnivores rely on human‐provided food, their densities are usually independent of prey densities. Nevertheless, underfed pets may need to hunt to meet their energetic and nutritional requirements. We explored the effects of different levels of care (provision of food) of dogs and cats on their predation rates on wild vertebrates in 2 areas of southern Chile. We interviewed cat and dog owners and analyzed prey remains in scats of pets to examine how domestic dogs and cats were managed and to gather information on the wild vertebrates killed and harassed by pets. We used logistic regression to examine the association between pet care and the frequency of wild vertebrate remains in scats. The probability of a dog preying on vertebrates was higher for poorly fed than for adequately fed dogs (odds ratio = 3.7) and for poorly fed than for adequately fed cats (odds ratio = 4.7). Domestic dogs and cats preyed on most endemic and threatened mammals present in the study sites. Our results provide support for the hypothesis that the less care domestic animals receive from owners the higher the probability those animals will prey on wild vertebrates.     

Aerobic Biodegradation of Hydrocarbons in High Temperature and Saline Groundwater

A series of laboratory microcosm experiments and a field pilot test were performed to evaluate the potential for aerobic biodegradation of aromatic hydrocarbons and methyl tert‐butyl ether (MtBE; a common oxygenate additive in gasoline) in saline, high temperature (>30° C) groundwater. Aquifer, sediment, and groundwater samples from two sites, one in Canada and another in Saudi Arabia, were incubated for 106 days to evaluate the changes in select hydrocarbon and MtBE concentrations and microbial community structure. Almost complete biodegradation of the aromatic hydrocarbons was found in the Saudi Arabian microcosm samples whereas the Canadian microcosm samples showed no significant biodegradation during the laboratory testing. MtBE degradation was not observed in either set of microcosms. Denaturing gradient gel electrophoresis analyses showed that, while the Canadian microorganisms were the most diverse, they showed little response during incubation. The microbial communities for the Saudi Arabian sample contained significant numbers of microorganisms capable of hydrocarbon degradation which increased during incubation. Based on the laboratory results, pilot‐scale testing at the Saudi Arabian field site was carried out to evaluate the effectiveness of enhanced aerobic biodegradation on a high temperature, saline petroleum hydrocarbon plume. Dissolved oxygen was delivered to the subsurface using a series of oxygen diffusion emitters installed perpendicular to groundwater flow, which created a reactive zone. Results obtained from the seven‐month field trial indicated that all the target compounds decreased with removal percentages varying between 33 percent for the trimethylbenzenes to greater than 80 percent for the BTEX compounds. MtBE decreased 40 percent on average whereas naphthalene was reduced 85 percent on average. Examination of the microbial population upgradient and downgradient of the emitter reactive zone suggested that the bacteria population went from an anaerobic, sulfate‐reducing dominated population to one dominated by a heterotrophic aerobic bacteria dominant population. These studies illustrate that field aerobic biodegradation may exceed expectations derived from simple laboratory microcosm experiments. Also, high salinity and elevated groundwater temperature do not appear to inhibit in situ aerobic biorestoration. © 2014 Wiley Periodicals, Inc.     

Comparing the Adoption of Contaminated Land Remediation Technologies in the United States,United Kingdom,and China

In many locations across the world, land contamination poses a serious threat to human health and the wider environment. For instance, a report published on April 17, 2014, revealed that China now has 16.1 percent of its land contaminated by various organic and inorganic contaminants, posing a range of challenges from human health risk to food security. The innovation and adoption of suitable remediation technologies is critical for solving land contamination issues. However, little is known about the pattern of remediation technology adoption, as well as its determining factors. This study uses a questionnaire survey in the United States, United Kingdom, and China to examine the spatial variation of remediation technology adoption. It further explores the temporal trend of remediation technology adoption using secondary data from the U.S. Superfund program. The study identified significant differences in remediation technology adoption among these countries, which are attributed to the different environmental, social, economic, and regulatory contexts. It is argued that the full implications of remediation technology adoption to sustainable development should be further studied, and policy instruments should be designed accordingly to promote those remediation technologies that align the best with long‐term sustainability. Technology developers may also use these implications to adjust their research and development priorities. © 2014 Wiley Periodicals, Inc.     

Measuring Protected‐Area Isolation and Correlations of Isolation with Land‐Use Intensity and Protection Status

Abstract: Protected areas cover over 12% of the terrestrial surface of Earth, and yet many fail to protect species and ecological processes as originally envisioned. Results of recent studies suggest that a critical reason for this failure is an increasing contrast between the protected lands and the surrounding matrix of often highly altered land cover. We measured the isolation of 114 protected areas distributed worldwide by comparing vegetation‐cover heterogeneity inside protected areas with heterogeneity outside the protected areas. We quantified heterogeneity as the contagion of greenness on the basis of NDVI (normalized difference vegetation index) values, for which a higher value of contagion indicates less heterogeneous land cover. We then measured isolation as the difference between mean contagion inside the protected area and mean contagion in 3 buffer areas of increasing distance from the protected‐area border. The isolation of protected areas was significantly positive in 110 of the 114 areas, indicating that vegetation cover was consistently more heterogeneous 10–20 km outside protected areas than inside their borders. Unlike previous researchers, we found that protected areas in which low levels of human activity are allowed were more isolated than areas in which high levels are allowed. Our method is a novel way to assess the isolation of protected areas in different environmental contexts and regions.     

Effects of Two Amphibian Pathogens on the Developmental Stability of Green Frogs

Abstract: Developmental instability, measured as fluctuating asymmetry (FA), is often used as a tool to measure stress and the overall quality of organisms. Under FA, it is assumed that control of symmetry during development is costly and that under stress the trajectory of development is disturbed, resulting in asymmetric morphologies. Amphibian emergent infectious diseases (EIDs), such as Ranavirus and chytrid fungus, have been involved in several mortality events, which makes them stressors and allows for the study of FA. We analyzed nine populations of green frogs (Rana clamitans) for the presence or absence of Ranavirus and chytrid fungus. Individuals were measured to determine levels of FA in seven traits under the hypothesis that FA is more likely to be observed in individuals infected by the pathogens. Significantly higher levels of FA were found in individuals with Ranavirus compared with uninfected individuals among all populations and all traits. We did not observe FA in individuals infected with chytrid fungus for any of the traits measured. Additionally, we observed a significant association between Ranavirus infection and levels of FA in both males and females, which may indicate this viral disease is likely to affect both sexes during development. Altogether, our results indicate that some EIDs may have far‐reaching and nonlethal effects on individual development and populations harboring such diseases and that FA can be used as a conservation tool to identify populations subject to such a stress.     

Traditional Ecological Knowledge Trends in the Transition to a Market Economy: Empirical Study in the Doñana Natural Areas

Abstract: Researchers and conservation managers largely agree on the relevance of traditional ecological knowledge for natural resource management in indigenous communities, but its prevalence and role as societies modernize are contested. We analyzed the transmission of traditional knowledge among rural local people in communities linked to protected areas in Doñana, southwestern Spain. We studied changes in knowledge related to local practices in agriculture and livestock farming among 198 informants from three generations that cover the period in which the area transited from an economy strongly dependent on local ecosystem services to a market economy with intensified production systems. Our results suggest an abrupt loss of traditional agricultural knowledge related to rapid transformations and intensification of agricultural systems, but maintenance of knowledge of traditional livestock farming, an activity allowed in the protected areas that maintains strong links with local cultural identity. Our results demonstrate the potential of protected areas in protecting remaining bodies of traditional ecological knowledge in developed country settings. Nevertheless, we note that strict protection in cultural‐landscape‐dominated areas can disrupt transmission of traditional knowledge if local resource users and related practices are excluded from ecosystem management.     

Building a Regionally Connected Reserve Network in a Changing and Uncertain World

Abstract: Habitat connectivity is required at large spatial scales to facilitate movement of biota in response to climatic changes and to maintain viable populations of wide‐ranging species. Nevertheless, it may require decades to acquire habitat linkages at such scales, and areas that could provide linkages are often developed before they can be reserved. Reserve scheduling methods usually consider only current threats, but threats change over time as development spreads and reaches presently secure areas. We investigated the importance of considering future threats when implementing projects to maintain habitat connectivity at a regional scale. To do so, we compared forward‐looking scheduling strategies with strategies that consider only current threats. The strategies were applied to a Costa Rican case study, where many reserves face imminent isolation and other reserves will probably become isolated in the more distant future. We evaluated strategies in terms of two landscape‐scale connectivity metrics, a pure connectivity metric and a metric of connected habitat diversity. Those strategies that considered only current threats were unreliable because they often failed to complete planned habitat linkage projects. The most reliable and effective strategies considered the future spread of development and its impact on the likelihood of completing planned habitat linkage projects. Our analyses highlight the critical need to consider future threats when building connected reserve networks over time.     

Effect of Small‐Scale Heterogeneity of Prey and Hunter Distributions on the Sustainability of Bushmeat Hunting

Abstract: Bushmeat is the main source of protein and the most important source of income for rural people in the Congo Basin, but intensive hunting of bushmeat species is also a major concern for conservationists. Although spatial heterogeneity in hunting effort and in prey populations at the landscape level plays a key role in the sustainability of hunted populations, the role of small‐scale heterogeneity within a village hunting territory in the sustainability of hunting has remained understudied. We built a spatially explicit multiagent model to capture the dynamics of a system in which hunters and preys interact within a village hunting territory. We examined the case of hunting of bay duikers (Cephalophus dorsalis) in the village of Ntsiété, northeastern Gabon. The impact of hunting on prey populations depended on the spatial heterogeneity of hunting and prey distribution at small scales within a hunting area. Within a village territory, the existence of areas hunted throughout the year, areas hunted only during certain seasons, and unhunted areas contributed to the sustainability of the system. Prey abundance and offtake per hunter were particularly sensitive to the frequency and length of hunting sessions and to the number of hunters sharing an area. Some biological parameters of the prey species, such as dispersal rate and territory size, determined their spatial distribution in a hunting area, which in turn influenced the sustainability of hunting. Detailed knowledge of species ecology and behavior, and of hunting practices are crucial to understanding the distribution of potential sinks and sources in space and time. Given the recognized failure of simple biological models to assess maximum sustainable yields, multiagent models provide an innovative path toward new approaches for the assessment of hunting sustainability, provided further research is conducted to increase knowledge of prey species’ and hunter behavior.     

Local Extinction of Dragonfly and Damselfly Populations in Low‐ and High‐Quality Habitat Patches

Abstract: Understanding the risk of extinction of a single population is an important problem in both theoretical and applied ecology. Local extinction risk depends on several factors, including population size, demographic or environmental stochasticity, natural catastrophe, or the loss of genetic diversity. The probability of local extinction may also be higher in low‐quality sink habitats than in high‐quality source habitats. We tested this hypothesis by comparing local extinction rates of 15 species of Odonata (dragonflies and damselflies) between 1930–1975 and 1995–2003 in central Finland. Local extinction rates were higher in low‐quality than in high‐quality habitats. Nevertheless, for the three most common species there were no differences in extinction rates between low‐ and high‐quality habitats. Our results suggest that a good understanding of habitat quality is crucial for the conservation of species in heterogeneous landscapes.     

Estimating the Value of Non‐Use Benefits from Small Changes in the Provision of Ecosystem Services

Abstract: The unit of trade in ecosystem services is usually the use of a proportion of the parcels of land associated with a given service. Valuing small changes in the provision of an ecosystem service presents obstacles, particularly when the service provides non‐use benefits, as is the case with conservation of most plants and animals. Quantifying non‐use values requires stated‐preference valuations. Stated‐preference valuations can provide estimates of the public's willingness to pay for a broad conservation goal. Nevertheless, stated‐preference valuations can be expensive and do not produce consistent measures for varying levels of provision of a service. Additionally, the unit of trade, land use, is not always linearly related to the level of ecosystem services the land might provide. To overcome these obstacles, we developed a method to estimate the value of a marginal change in the provision of a non‐use ecosystem service—in this case conservation of plants or animals associated with a given land‐cover type. Our method serves as a tool for calculating transferable valuations of small changes in the provision of ecosystem services relative to the existing provision. Valuation is achieved through stated‐preference investigations, calculation of a unit value for a parcel of land, and the weighting of this parcel by its ability to provide the desired ecosystem service and its effect on the ability of the surrounding land parcels to provide the desired service. We used the water vole (Arvicola terrestris) as a case study to illustrate the method. The average present value of a meter of water vole habitat was estimated at UK£12, but the marginal value of a meter (based on our methods) could range between £0 and £40 or more.