The Role of Landowners in Jaguar Conservation in Sonora,Mexico

Abstract: The northernmost known breeding population of jaguars occurs in the municipality of Nácori Chico, Sonora, Mexico about 270 km from the United States–Mexico border and may be the source from which jaguars sighted in the United States dispersed. Since 1999 at least 11 jaguars (Panthera onca) had been illegally killed in the area due to predator control programs. We initiated a jaguar landowner‐based conservation plan in 2004. The eight participating landowners agreed to suspend predator control programs targeting jaguars and pumas (Puma concolor) only if cattle losses were compensated. A private outfitter, with the consent of landowners, initiated white‐tailed deer (Odocoileus virginianus) hunts in 2004 and agreed to pay the group of participating landowners US$1500 for every deer hunt permit sold. The funds paid to the landowners from deer hunts were sufficient to convince landowners to suspend all predator‐control efforts of jaguars and pumas. The involvement of landowners in the jaguar conservation program in northeastern Sonora is a successful, private, wildlife‐conservation initiative that provides an example for jaguar conservation efforts in northern Mexico.     

Experimental evaluation of emission factors of cement kilns burning hazardous wastes

Cement industry is an interesting way to eliminate combustible wastes. Thermal valorization is maximal, conditions of combustion are especially favorable to the destruction and the trapping of pollutants, and there are neither ultimate residues (slag) nor aqueous rejects. Moreover the properties of the cement are not modified. Nevertheless the increased use of substitution fuel may lead to deal with unusual amounts of heavy metals. Tests were realized on several rotary cement kilns with varying substitution ratios of fossil fuels by wastes. Mass balances were fitted over the whole plant, and emission factors were explained.     

A new hypothesis concerning the nature of small pelagic fish clusters: An individual-based modelling study of Sardinella aurita dynamics off West Africa

Coastal populations of small pelagic fish display nested aggregation levels. Above the level of the school structure, clusters are observed the nature of which has not been definitively determined. We hypothesized that these clusters corresponded to a materialisation of the microcohorts originating from successive spawnings of fish populations in their vital domain.A candidate individual-based model was developed to investigate this hypothesis. This model is based on pattern-oriented modelling of a concrete documented case: the dynamics of the round sardinella (Sardinella aurita) population living off the West African coasts and subject to environmental fluctuations caused by seasonal upwelling. The simulated agents were round sardinella microcohorts situated and moving in a discretised physical environment. The combined effects of environmental forcing (temperature, wind, retention) and inner biological dynamics (reproduction, growth and mortality, competition) condition the dynamics of this population.The modelled behaviour generated realistic dynamic patterns (population distribution, spawning zones, periods and plasticity, biomass fluctuations), which were obtained simultaneously and successfully compared with observations. The steady-state number of microcohorts obtained after simulation convergence was similar to the number of clusters observed in situ in this area for this population.The realism and diversity of the patterns simultaneously simulated suggested the cluster-microcohort equivalence hypothesis as a candidate framework accounting for the origin of the clusters observed in situ. Within this preliminary exploration, we discuss the consistency of the hypothesis and the accuracy of the model. If the correspondence between clusters and microcohorts proves to be real, it may be transient and progressively modified by other environmental factors. If stable over time, as simulated in the model, the number of observed clusters should be related to the number of spawning events in the species’ lifetime.     

Biodiversity of brackish water amphipods (crustacean) in two estuaries, southeast coast of India

The present study about the gammarid amphipods of Vellar and Uppanar estuaries was performed during two seasons (pre-monsoon and post-monsoon, 2005–2006), respectively, in nine habitats: five in the Vellar estuary and four in the Uppanar estuary. Amphipod samples were collected from sediments, oyster beds, seaweeds, sea grass, and mangroves. A total of 29 species of gammarid amphipods were collected in each area. The surface water temperature ranged from 16°C to 26°C, the salinity from 20 to 32 psu, and the pH between 7.5 and 8.3. Dissolved oxygen ranged from 5.3 to 7.8 ml/l. The maximum abundance of amphipods was observed during the pre-monsoon (July to September) in Vellar mangrove, and it was minimum during the pre-monsoon in Uppanar sea grass. It was found that several physicochemical factors, such as salinity, temperature, dissolved oxygen, pH, and the substrate have a marked effect on the distribution and the relative abundance of amphipods. The ranges of species diversity, richness, dominance, and evenness in the Vellar and Uppanar estuaries were 1.58–4.15, 1.82–5.29, 0–0.11, and 0.96–1, respectively. Using multivariate analyses, in each estuary, it was possible to identify different communities of amphipod species according to their habitats.     

Experimental Test of Postfire Management in Pine Forests: Impact of Salvage Logging versus Partial Cutting and Nonintervention on Bird–Species Assemblages

Abstract: There is an intense debate about the effects of postfire salvage logging versus nonintervention policies on regeneration of forest communities, but scant information from experimental studies is available. We manipulated a burned forest area on a Mediterranean mountain to experimentally analyze the effect of salvage logging on bird–species abundance, diversity, and assemblage composition. We used a randomized block design with three plots of approximately 25 ha each, established along an elevational gradient in a recently burned area in Sierra Nevada Natural and National Park (southeastern Spain). Three replicates of three treatments differing in postfire burned wood management were established per plot: salvage logging, nonintervention, and an intermediate degree of intervention (felling and lopping most of the trees but leaving all the biomass). Starting 1 year after the fire, we used point sampling to monitor bird abundance in each treatment for 2 consecutive years during the breeding and winter seasons (720 censuses total). Postfire burned‐wood management altered species assemblages. Salvage logged areas had species typical of open‐ and early‐successional habitats. Bird species that inhabit forests were still present in the unsalvaged treatments even though trees were burned, but were almost absent in salvage‐logged areas. Indeed, the main dispersers of mid‐ and late‐successional shrubs and trees, such as thrushes (Turdus spp.) and the European Jay (Garrulus glandarius) were almost restricted to unsalvaged treatments. Salvage logging might thus hamper the natural regeneration of the forest through its impact on assemblages of bird species. Moreover, salvage logging reduced species abundance by 50% and richness by 40%, approximately. The highest diversity at the landscape level (gamma diversity) resulted from a combination of all treatments. Salvage logging may be positive for bird conservation if combined in a mosaic with other, less‐aggressive postfire management, but stand‐wide management with harvest operations has undesirable conservation effects.     

Uptake of cadmium into cells in culture∗

Cadmium has been recognized as pollutant of the environment for many years and numerous studies on its toxic effects have been carried out. Little, however, is known about its metabolic behaviour e.g. why the metal is accumulated so extremely rapidly into the organs of men and animals. Since the study of the individual metabolic steps is very difficult in vivo cell cultures may be used to obtain first indications of what happens in the whole animal.

We used CHO cells in monolayer culture to study the conditions under which the uptake of cadmium occurs. From serumfree medium the metal is accumulated rapidly in the cells. The uptake is inhibited very strongly by the presence of serum or albumin. Accumulation occurs against a concentration gradient and is dependent on the incubation temperature. Below 10°C no cadmium uptake is seen. Several substances which are known to affect cell metabolism have been used to influence cadmium accumulation. Neither inhibitors of energy production nor microtubule or microfilament disruptors showed any substantial effect. In contrast SH‐group blocking agents markedly reduced cadmium uptake.

The results show that cadmium uptake does not occur by passive diffusion but by some active mechanism.     

Use of Market Data to Assess Bushmeat Hunting Sustainability in Equatorial Guinea

Abstract: Finding an adequate measure of hunting sustainability for tropical forests has proved difficult. Many researchers have used urban bushmeat market surveys as indicators of hunting volumes and composition, but no analysis has been done of the reliability of market data in reflecting village offtake. We used data from urban markets and the villages that supply these markets to examine changes in the volume and composition of traded bushmeat between the village and the market (trade filters) in Equatorial Guinea. We collected data with market surveys and hunter offtake diaries. The trade filters varied depending on village remoteness and the monopoly power of traders. In a village with limited market access, species that maximized trader profits were most likely to be traded. In a village with greater market access, species for which hunters gained the greatest income per carcass were more likely to be traded. The probability of particular species being sold to market also depended on the capture method and season. Larger, more vulnerable species were more likely to be supplied from less‐accessible catchments, whereas there was no effect of forest cover or human population density on probability of being sold. This suggests that the composition of bushmeat offtake in an area may be driven more by urban demand than the geographic characteristics of that area. In one market, traders may have reached the limit of their geographical exploitation range, and hunting pressure within that range may be increasing. Our results demonstrate that it is possible to model the trade filters that bias market data, which opens the way to developing more robust market‐based sustainability indices for the bushmeat trade.     

Cost‐Effectiveness of Translocation Options for a Threatened Waterbird

Abstract: Reintroduction of captive‐reared animals has become increasingly popular in recent decades as a conservation technique, but little is known of how demographic factors affect the success of reintroductions. We believe whether the increase in population persistence associated with reintroduction is sufficient to warrant the cost of rearing and relocating individuals should be considered as well. We examined the trade‐off between population persistence and financial cost of a reintroduction program for Crested Coots (Fulica cristata). This species was nearly extirpated from southern Europe due to unsustainable levels of hunting and reduction in amount and quality of habitat. We used a stochastic, stage‐based, single‐sex, metapopulation model with site‐specific parameters to examine the demographic effects of releasing juveniles or adults in each population for a range of durations. We parameterized the model with data from an unsuccessful reintroduction program in which juvenile captive‐bred Crested Coots were released between 2000 and 2009. Using economic data from the captive‐breeding program, we also determined whether the strategy that maximized abundance coincided with the least expensive strategy. Releasing adults resulted in slightly larger final abundance than the release of nonreproductive juveniles. Both strategies were equally poor in achieving a viable metapopulation, but releasing adults was 2–4 times more expensive than releasing juveniles. To obtain a metapopulation that would be viable for 30 years, fecundity in the wild would need to increase to the values observed in captivity and juvenile survival would need to increase to almost unity. We suggest that the most likely way to increase these vital rates is by increasing habitat quality at release sites.     

Hunter Reporting of Catch per Unit Effort as a Monitoring Tool in a Bushmeat‐Harvesting System

Abstract: Growing threats to biodiversity in the tropics mean there is an increasing need for effective monitoring that balances scientific rigor with practical feasibility. Alternatives to professional techniques are emerging that are based on the involvement of local people. Such locally based monitoring methods may be more sustainable over time, allow greater spatial coverage and quicker management decisions, lead to increased compliance, and help encourage attitude shifts toward more environmentally sustainable practices. Nevertheless, few studies have yet compared the findings or cost‐effectiveness of locally based methods with professional techniques or investigated the power of locally based methods to detect trends. We gathered data on bushmeat‐hunting catch and effort using a professional technique (accompanying hunters on hunting trips) and two locally based methods in which data were collected by hunters (hunting camp diaries and weekly hunter interviews) in a 15‐month study in Equatorial Guinea. Catch and effort results from locally based methods were strongly correlated with those of the professional technique and the spatial locations of hunting trips reported in the locally based methods accurately reflected those recorded with the professional technique. We used power simulations of catch and effort data to show that locally based methods can reliably detect meaningful levels of change (20% change with 80% power at significance level [α]= 0.05) in multispecies catch per unit effort. Locally based methods were the most cost‐effective for monitoring. Hunter interviews collected catch and effort data on 240% more hunts per person hour and 94% more hunts per unit cost, spent on monitoring, than the professional technique. Our results suggest that locally based monitoring can offer an accurate, cost‐effective, and sufficiently powerful method to monitor the status of natural resources. To establish such a system in Equatorial Guinea, the current lack of national and local capacity for monitoring and management must be addressed.