A Behaviorally Explicit Demographic Model Integrating Habitat Selection and Population Dynamics in California Sea Lions

Abstract: Although there has been a call for the integration of behavioral ecology and conservation biology, there are few tools currently available to achieve this integration. Explicitly including information about behavioral strategies in population viability analyses may enhance the ability of conservation biologists to understand and estimate patterns of extinction risk. Nevertheless, most behavioral‐based PVA approaches require detailed individual‐based data that are rarely available for imperiled species. We present a mechanistic approach that incorporates spatial and demographic consequences of behavioral strategies into population models used for conservation. We developed a stage‐structured matrix model that includes the costs and benefits of movement associated with 2 habitat‐selection strategies (philopatry and direct assessment). Using a life table for California sea lions (Zalophus californianus), we explored the sensitivity of model predictions to the inclusion of these behavioral parameters. Including behavioral information dramatically changed predicted population sizes, model dynamics, and the expected distribution of individuals among sites. Estimated population sizes projected in 100 years diverged up to 1 order of magnitude among scenarios that assumed different movement behavior. Scenarios also exhibited different model dynamics that ranged from stable equilibria to cycles or extinction. These results suggest that inclusion of behavioral data in viability models may improve estimates of extinction risk for imperiled species. Our approach provides a simple method for incorporating spatial and demographic consequences of behavioral strategies into population models and may be easily extended to other species and behaviors to understand the mechanisms of population dynamics for imperiled populations.     

Monitoring SARS-CoV-2 in the Wastewater and Rivers of Tapachula,a Migratory Hub in Southern Mexico

Food and Environmental Virology - The COVID-19 pandemic has been monitored by applying different strategies, including SARS-CoV-2 detection with clinical testing or through wastewater-based...     

Population Viability Analysis of Captive and Released Bearded Vulture Populations

With the computer program VORTEX I ran a series of simulations of the Bearded Vulture ( Gypaetus barbatus ) population held in captivity in European zoos and of the population released in the Alps. The simulations showed that the risk of extinction of the captive population with the extraction rates currently in use is low. It seems possible to maintain the current release rate of two fledglings per year at each of the four release sites in the Alps, but it does not seem possible to increase the release rate by expanding the project to other European mountains without dangerously depleting the captive population. The models showed that the most effective way to increase the release rate without increasing the captive population size is by improving hatching success in captivity. The information on the demographic parameters of the Bearded Vulture population released in the Alps was not good enough to predict the ultimate fate of the present population or to allow for recommendations on how long the population should continue to be supplemented. Although it will be necessary to wait some years to see if Bearded Vultures are able to breed in the wild in the Alps and to estimate fecundity rates, it should be possible to improve the monitoring of the individuals released to obtain more-precise survival estimates. The models of the captive and released population also showed that it should at least be possible to have an artificially supplemented Bearded Vulture population in the Alps, but because this is not the goal of the present reintroduction project, the organizations involved should decide whether this is a politically or economically desirable goal.     

Hybridization and the Extinction of Rare Plant Species

Much has been written about the role of interspecific competition, disease, herbivory, and the loss of key mutualisms in the extinction of rare plant species. Interspecific hybridization rarely is considered among the biotic interactions that promote extinction. We show how hybridization may contribute to the demise of rare plant species through demographic swamping and genetic assimilation by an abundant congener. We contend that the growth of the hybrid subpopulation is the key to rare species assimilation, and we show how the production of hybrid seed, the fitness of hybrids, and pest pressure affect hybrid proliferation. We also discuss how habitat disturbance, unspecialized pollinators, and weak crossing barriers promote hybridization, and how the negative consequences of hybridization are unlikely to be compensated for by immigration from conspecific populations. We also illustrate stages in the demise of species in island floras. We suggest that hybridization is an increasing threat to rare species because ecological barriers are being disrupted by human activities.     

Analysis of PM10, PM2.5, and PM2 5-10 concentrations in Santiago, Chile, from 1989 to 2001

Daily particle samples were collected in Santiago, Chile, at four urban locations from January 1, 1989, through December 31, 2001. Both fine PM with da < 2.5 microm (PM2.5) and coarse PM with 2.5 < da < 10 microm (PM2.5-10) were collected using dichotomous samplers. The inhalable particle fraction, PM10, was determined as the sum of fine and coarse concentrations. Wind speed, temperature and relative humidity (RH) were also measured continuously. Average concentrations of PM2.5 for the 1989-2001 period ranged from 38.5 microg/m3 to 53 microg/m3. For PM2.5-10 levels ranged from 35.8-48.2 microg/m3 and for PM10 results were 74.4-101.2 microg/m3 across the four sites. Both annual and daily PM2.5 and PM10 concentration levels exceeded the U.S. National Ambient Air Quality Standards and the European Union concentration limits. Mean PM2.5 levels during the cold season (April through September) were more than twice as high as those observed in the warm season (October through March); whereas coarse particle levels were similar in both seasons. PM concentration trends were investigated using regression models, controlling for site, weekday, month, wind speed, temperature, and RH. Results showed that PM2.5 concentrations decreased substantially, 52% over the 12-year period (1989-2000), whereas PM2.5-10 concentrations increased by approximately 50% in the first 5 years and then decreased by a similar percentage over the following 7 years. These decreases were evident even after controlling for significant climatic effects. These results suggest that the pollution reduction programs developed and implemented by the Comisión Nacional del Medio Ambiente (CONAMA) have been effective in reducing particle levels in the Santiago Metropolitan region. However, particle levels remain high and it is thus imperative that efforts to improve air quality continue.     

New Device Against Non-Thermal Effects from Mobile Telephones

Summary Objectives: The aim of this study is to initiate research in the field of biomedical engineering geared towards a reduction of non-thermal effects on the brain due to the use of mobile telephones. This line of research employs devices attached to the back of cellular-telephone cases. Methods: Under electromagnetic-environment controlled conditions EEG records have been obtained in 16 healthy subjects, with their eyes open at the base-line. These records were compared with the use of the mobile telephone with and without one of these devices for five minutes each, and having them statistically tested with Wilcoxon matched-pairs. Results: Differences between experimental EEG, with and without the use of the device, have been observed. These subtle changes basically affect Delta and Theta wave bands. Their distribution, (changes in the affected areas of the brain), also varies, above all in the frontal areas. Conclusions: The use of this device could reduce non-thermal effects of mobile telephones on the human EEG.     

Not Only Single Mating in Stingless Bees

Queens of the large, pantropical and fully eusocial taxon Meliponinae (stingless bees) are generally considered to be singly mated. We indirectly estimated queen mating frequency in two meliponids, Melipona beecheii and Scaptotrigona postica, by examining genotypes of workers at microsatellite DNA loci. Microsatellites were highly variable, providing suitable markers with which to assign patrilinial origin of workers within colonies headed by single queens. Queen mating frequency varied between 1 and 3 (M. beecheii) and 1 and 6 (S. postica), representing the first clear documentation of polyandry in the Meliponinae. Effective paternity frequency, m _e , was lower, although above 2 for S. postica. Stingless bees may provide suitable subjects for the testing of recent inclusive fitness arguments describing intracolony kin conflict in social Hymenoptera. Received: 26 August 1998 / Accepted in revised form: 18 November 1998     

Diversity of eco-innovations: Reflections from selected case studies

An analytical framework is developed in this paper in order to explore the diversity of eco-innovations according to several key dimensions (design, user, product service and governance). The framework is used to analyse a set of case studies of eco-innnovation processes. The diversity of the analysed eco-innovations appears to be considerable; each of them involves different kinds of combinations of elements pertaining to those dimensions. Albeit the design dimension is decisive to determine the environmental impacts of the innovation, all dimensions can play a significant role in the management of eco-innovation. Our findings suggest that the capacity of eco-innovations to provide new business opportunities and contribute to the transformation towards a sustainable society depends on the interplay of those dimensions and the engagement of key stakeholders in the innovation process.