1,763 research outputs found
The future of sustainability in the context of COVID-19
The COVID-19 pandemic is a global crisis emanating both from a virus (SARS-CoV-2) and from the drastic actions to contain it. Here, we reflect on the immediate responses of most world powers amid the pandemic chaos: totalitarian surveillance and nationalist isolation. Drawing on published literature, we consider measures such as wildlife-use bans, lockdowns and travel restrictions, along with their reverberations for people, economies and the planet. Our synthesis highlights significant shortfalls of applying command-and-control tactics in emergencies. For one, heavy-handed bans risk enormous unintended consequences and tend to fail if they lack legitimacy or clash with people’s values. Furthermore, reactive and myopic strategies typically view the pandemic as a stand-alone crisis, rather than unravelling the complex interplay of nature-society interactions through which zoonotic diseases originate. A return to adaptive management approaches that recognise root causes and foster socio-ecological resilience will be essential to improve human and planetary health and mitigate future pandemics
Multiple-Criteria Decision Analysis and characterisation of phase change materials for waste heat recovery at high temperature for sustainable energy-intensive industry
A latent heat storage system based on Phase Change Materials (PCMs) is proposed to increase the energy and environmental efficiency by recovering and storing waste heat from combustion gases or other surplus sources at in the energy-intensive industries (EII), currently unused. The final configuration design is specifically adapted to the plant operational requirements, by means of a methodology combining the search of the best conceptual design and a proper selection of core PCMs. To that end, a selection of suitable PCM is carried out by using characterisation techniques and thermal stability testing. Furthermore, relevant key factors are weighted by an in-house Multiple-Criteria Decision Analysis (MCDA) to define the most promising design options to be implemented in two plants belonging to the EII sector. For the ceramic sector, the design resulted in a shell-and-tube system with 1188 kg of a PCM melting at 885 °C and encapsulated in double concentric tubes, involving a storage capacity of 227 MJ. Similarly, 1606 kg of PCM, whose phase-change temperature is 509 °C, is selected for the steel sector providing a PCM-TES system capable to store 420 MJ
Challenges and opportunities for monitoring wild Nile crocodiles with scute mark-recapture photography
The global conservation status of Nile crocodiles (Crocodylus niloticus) was last assessed in 1996. The species presents particular difficulty in monitoring because it can be cryptic, require expertise to handle, and caudal tail tags and transmitters are often lost. Some studies advocate mark-recapture techniques based on photograph identification of the unique scute markings of crocodile tails as a non-invasive means of monitoring their populations. Researchers developed this method with crocodiles in captivity. In this study, we test the technique under field conditions by monitoring crocodiles from 2015 to 2017 in the Sunset Dam in the Kruger National Park. Using a Cormack-Jolly-Seber open population model, we found that the dam may host 15–30 individuals, but that there is a high turnover of individuals and much uncertainty in model outputs. The dam’s population thus has high rates of immigration and emigration. The method proved challenging under field conditions, as there was bias in identifying scute markings consistently. The efficient use of the method requires an exceptional quality of photographic equipment. Animal crypsis, however, remains an issue. In this study, we discuss how to improve the mark-recapture photography methodology, especially to adapt the technique for citizen science initiatives.
Conservation implications:Â Using scute mark-recapture photography presents challenges under field conditions. These challenges require innovative, practical and analytical solutions to successfully use the technique before monitoring programmes, aimed at ensuring the persistence of crocodiles in the wild, can be implemented
The effect(s) of carbaryl-treated seed on body maintenance and survival of the multi-mammate mouse, Mastomys natalensis (sensu lato)
Maintenance, expressed as change in daily body mass, and survival rates of Mastomys natalensis (sensu lato) were recorded from May to September 1994 in laboratory feeding trials, to investigate the short-term effects of a carbaryl insecticide on these variables. Individuals were subjected to seeds treated with carbaryl insecticide in three different treatments (5, 10 and 20 g of carbaryl/kg of seeds). Carbaryl did not have short-term adverse effects on growth and survival of this species when the seeds were kept in the laboratory and when they were exposed to environmental conditions between measurements. This suggests that the ingestion of carbaryl-treated seeds is not the cause of the decline in density of M. natalensis on rehabilitating coastal dune forests at Richards Bay.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Richards Bay Minerals. Endangered Wildlife
Trust's Eddie Young Memorial Fund. Foundation
for Research Development.mn201
Calibrating a camera trap-based biased mark-recapture sampling design to survey the leopard population in the N'wanetsi concession, Kruger National Park, South Africa
Estimating large carnivore abundance can be challenging.
A biased leopard (Panthera pardus) population survey was
conducted in the N’wanetsi concession in the Kruger
National Park (KNP), South Africa, using motion-sensitive
camera traps from April to August 2008. Survey effort
included 88 trapping occasions and 586 trap days. The
survey yielded 24 leopard photographs, comprising fourteen
adults of eleven males and three females. The capture
rate was determined to be 24.4 trap days per leopard.
Estimates of population abundance stabilized at approximately
500 trap days. Precision of population estimates
began to stabilize after 378 trap days. We estimated that
there were nineteen leopards in an area of 150 km2.
Leopard density was estimated at 12.7 leopards per
100 km2. We explore the possibility of employing the
methods used in this study to survey the leopard population
in the KNP and surrounding areas.The KCS Pacific Foundation, The Nancy-Carroll Draper Foundation, and WESSA.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2028hb2013ab201
The white rhino can again be a conservation success
No abstract available.https://zslpublications.onlinelibrary.wiley.com/journal/14691795hj2023Mammal Research InstituteZoology and Entomolog
Age Determination by Back Length for African Savanna Elephants: Extending Age Assessment Techniques for Aerial-Based Surveys
Determining the age of individuals in a population can lead to a better understanding of population dynamics through age structure analysis and estimation of age-specific fecundity and survival rates. Shoulder height has been used to accurately assign age to free-ranging African savanna elephants. However, back length may provide an analog measurable in aerial-based surveys. We assessed the relationship between back length and age for known-age elephants in Amboseli National Park, Kenya, and Addo Elephant National Park, South Africa. We also compared age- and sex-specific back lengths between these populations and compared adult female back lengths across 11 widely dispersed populations in five African countries. Sex-specific Von Bertalanffy growth curves provided a good fit to the back length data of known-age individuals. Based on back length, accurate ages could be assigned relatively precisely for females up to 23 years of age and males up to 17. The female back length curve allowed more precise age assignment to older females than the curve for shoulder height does, probably because of divergence between the respective growth curves. However, this did not appear to be the case for males, but the sample of known-age males was limited to ≤27 years. Age- and sex-specific back lengths were similar in Amboseli National Park and Addo Elephant National Park. Furthermore, while adult female back lengths in the three Zambian populations were generally shorter than in other populations, back lengths in the remaining eight populations did not differ significantly, in support of claims that growth patterns of African savanna elephants are similar over wide geographic regions. Thus, the growth curves presented here should allow researchers to use aerial-based surveys to assign ages to elephants with greater precision than previously possible and, therefore, to estimate population variables
Spatial constraints and seasonal conditions but not poaching pressure are linked with elevated faecal glucocorticoid metabolite concentrations in white rhino
DATA AVAILABILTY : The data that support the findings of this study are available from the Science Manager at South African National Parks Mrs Judith Botha
([email protected]), upon reasonable request.CONTEXT : Due to considerable declines in African wildlife populations, most large African mammals
are managed inside protected areas. Protected areas come in various sizes, and have different
environmental features, climates and management strategies (i.e. ‘hands-on’ or ‘hands-off’) that can
influence an animals’ homeostasis. White rhinos (Ceratotherium simum simum) are found almost
exclusively within protected areas where population sizes are driven by natural factors and
poaching pressures. AIMS : Our aim was to understand the effect of natural and anthropogenic
factors on the adrenocortical response of white rhinos within three protected areas. Specifically,
we wanted to understand how poaching pressure, protected area size (<500 km2), season (wet
and dry) and rainfall patterns were responsible for driving adrenocortical activity in white rhino.
METHODS : To understand the relationship between rhino adrenocortical responses and different
environmental and anthropogenic stressors, we quantified glucocorticoid metabolites in faecal
samples (fGCM) collected from four populations within three protected areas (i.e. two small
parks, one big park) during the wet and dry seasons. KEY RESULTS : We found differences in
seasonal fGCM concentrations, with a 42% increase during the dry season, and no differences in
fGCM concentrations between the high and low poaching areas. Additionally, we found fGCM
concentrations in samples from the small parks were respectively 38% and 42% higher than in
samples from the large park during both the dry and wet seasons compared. CONCLUSIONS : Our
results suggest that white rhinos may experience physiological stress in smaller parks, especially
during the dry season when resources are limited. IMPLICATIONS : By mitigating stress associated
with reduced access to resources and spatial constraints, managers may better promote the
viability of large mammals in small protected areasThe South African National Parks.https://www.publish.csiro.au/WRhj2023Mammal Research Institut
Simplified large African carnivore density estimators from track indices
BACKGROUND: The range, population size and trend of large carnivores are important parameters to assess their status globally and to plan conservation strategies. One can use linear models to assess population size and trends of large carnivores from track-based surveys on suitable substrates. The conventional approach of a linear model with intercept may not intercept at zero, but may fit the data better than linear model through the origin. We assess whether a linear regression through the origin is more appropriate than a linear regression with intercept to model large African carnivore densities and track indices.
METHODS : We did simple linear regression with intercept analysis and simple linear regression through the origin and used the confidence interval for ß in the linear model y = αx + ß, Standard Error of Estimate, Mean Squares Residual and Akaike Information Criteria to evaluate the models.
RESULTS : The Lion on Clay and Low Density on Sand models with intercept were not significant (P > 0.05). The other four models with intercept and the six models thorough origin were all significant (P < 0.05). The models using linear regression with intercept all included zero in the confidence interval for ß and the null hypothesis that ß = 0 could not be rejected. All models showed that the linear model through the origin provided a better fit than the linear model with intercept, as indicated by the Standard Error of Estimate and Mean Square Residuals. Akaike Information Criteria showed that linear models through the origin were better and that none of the linear models with intercept had substantial support.
DISCUSSION : Our results showed that linear regression through the origin is justified over the more typical linear regression with intercept for all models we tested. A general model can be used to estimate large carnivore densities from track densities across species and study areas. The formula observed track density = 3.26 × carnivore density can be used to estimate densities of large African carnivores using track counts on sandy substrates in areas where carnivore densities are 0.27 carnivores/100 km2 or higher. To improve the current models, we need independent data to validate the models and data to test for non-linear relationship between track indices and true density at low densities.Christiaan Winterbach was funded by the National Research Foundation, South Africa,
Grant No: 95399.https://peerj.comam2017Centre for Wildlife Managemen
Potential Use of Bio-Oleogel as Phase Change Material
Two bio-oleogels were investigated. These materials were produced with a combination of canola and soybean oil with 4, 6, 8, and 10% of beeswax (by weight). Sensible heat storage capacity, melting parameters, and enthalpies were investigated by the differential scanning calorimetry (DSC) test. An ordinary DSC dynamic test was performed. Cycles of heating and cooling were performed, as well as tests with different heating rates. According to the results, the materials present a melting temperature between −16 to −12 °C and a total latent heat between 22.9 and 367.6 J/g. BC10 (canola oil with 10% beeswax) was the sample with the best performance, with a latent heat of 367.6 J/g and a melting temperature of −13.6 °C, demonstrating its possible use as a phase change material for cold storage
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