What camera traps tell us about elephants eating crops

First paragraph: An important conservation goal is to try and ensure that people and wildlife can coexist. This is especially important when it comes to elephants, whose large home ranges and long distance movements take them outside of protected areas

A new method for the separation of androgens from estrogens and for the partition of estriol from the estrone-estradiol fraction: with special reference to the identification and quantitative microdetermination of estrogens by ultraviolet absorption spectrophotometry

It is recognized generally that a qualitative and quantitative knowledge of the excretion pattern of the urinary estrogens is one index to an understanding of the functional activity of the ovary and adrenal cortex. Obviously, such determinations may be useful also in evaluating the normal and abnormal functions of other physiologically related endocrine glands as well as of organs like the liver and kidneys. The clinical applications of these data are self-evident. Various attempts have been made to circumvent the notoriously inaccurate values which have been obtained for the urinary estrogens by a variety of bioassay methods and calorimetric techniques (1, 2). The acknowledged shortcomings of these methods have led us to investigate the application of ultraviolet absorption spectrophotometry to the quantitative determination of the urinary estrogens in an attempt to develop an objective physical method for their accurate determination. It is known that the infra-red portion of the spectrum yields more differentially characteristic curves, but those of the ultraviolet range are more readily obtainable, and consequently better adapted to clinical use. This communication is concerned with studies of the following aspects of the problem: (1) spectrophotometric identification and quantitative micro determination of crystalline estrogens; (2) detection by spectrophotometric assay of gross errors in current methods for extraction and partition of estrogens; (3) studies on the ultraviolet absorption of substances comprising the background material; (4) separation of the phenolic estrogens from the so called neutral steroid fraction; (5) separation of urinary estrogens from other urinary phenolic substances by steam distillation; (6) micro-Girard separation of estrone from estradiol; (7) an essentially new method for the extraction and partition of crystalline estrone, estradiol, and estriol, and their quantitative assay by ultraviolet spectrophotometry

Elephants in a landscape of risk: spatial, temporal, and behavioural responses to anthropogenic risk in African savannah elephants

African savanna elephant (Loxodonta africana) populations have declined due to poaching for the ivory trade. Elephants and humans also increasingly share ranges and resources. This thesis investigates whether and how human-mediated risk influences elephant space use, activity patterns, resource use, grouping patterns, and sex differences in responses to risk, in the Ruaha-Rungwa ecosystem, Tanzania. This area experienced multiple poaching surges and has increasing levels of human activity. I applied occupancy models to elephant occurrence data to investigate space use in relation to risk and environmental factors. Elephant occurrence was negatively associated with human population densities and conversion to agriculture, as well as elephant carcass occurrence (a proxy for poaching risk) and illegal human use. Using camera trap data I compared active periods, grouping patterns, and use of roads and water sources at one low-risk site and three high-risk sites. Male and female elephants were more nocturnal in high-risk versus low-risk sites, including use of water sources; this was more pronounced for cow-calf groups than for lone males. In the high-risk versus low-risk sites, elephants were active for less time overall, avoided movement on roads, and male elephants associated more with males and cow-calf groups. I assessed how risk influences elephant use of water sources using camera trap data. Elephant use of a high-risk resource was driven by seasonal variation in water availability, and use of high-risk water sources was more nocturnal than use of low-risk water sources. Males, but not females, adjusted group size in relation to risk. I discuss costs associated with risk-induced behavioural shifts, including a reduction in total active time and effects on body condition, and show that the consequences of elephant poaching in Ruaha-Rungwa extend beyond effects on population size and structure. I suggest that risk-avoidance behaviour may enable elephants to persist in increasingly human-dominated landscapes

Using camera traps to study the age-sex structure and behaviour of crop-using elephants Loxodonta africana in Udzungwa Mountains National Park, Tanzania

Crop losses from elephants are one of the primary obstacles to the coexistence of elephants and people and one of the contributing causes to elephant population decline. Understanding if some individuals in an elephant population are more likely to forage on crops, and the temporal patterns of elephant visits to farms, is key to mitigating the negative impacts of elephants on farmers. We used camera traps as a novel technique to study elephant crop foraging behaviour in farmland adjacent to the Udzungwa Mountains National Park in southern Tanzania from October 2010 to August 2014. Camera traps placed on elephant trails into farmland captured elephants on 336 occasions over the four-year study period. We successfully identified individual elephants from camera trap images for 126 of these occasions. All individuals detected on the camera traps were independent males, and we identified 48 unique bulls aged between 10 and 29 years. Two-thirds of the bulls identified were detected only once by camera traps over the study period, a pattern that also held during the last year of study when camera trapping effort was continuous. Our findings are consistent with previous studies that found that adult males are more likely to adopt high-risk feeding behaviours such as crop foraging, though young males dispersing from maternal family units also consume crops in Udzungwa. Our study found a large number of occasional crop-users (32 of the 48 bulls identified) and a smaller number of repeat crop-users (16 out of 48), suggesting that lethal elimination of crop-using elephants is unlikely to be an effective long-term strategy for reducing crop losses from elephants

Age structure as an indicator of poaching pressure: insights from rapid assessments of elephant populations across space and time

Detecting and monitoring illegal harvesting pressure on wild populations is challenging due to the cryptic nature of poaching activities. Although change in population age structure has been suggested as an indicator of harvesting pressure, few studies have tested its validity when based on short-term field surveys. Using data from rapid demographic assessment surveys carried out in 2009 at six sites in Tanzania, we examined whether African elephant populations experiencing contrasting levels of poaching pressure showed significant differences in their age structure, operational sex ratio (i.e. adult males to adult females), dependent individual to adult female ratio at the group level, and proportion of tuskless individuals. We also compared similar metrics between the population sampled in Ruaha National Park in 2009 and again in 2015 following a suspected increase in poaching. Elephant populations experiencing medium and high levels of poaching in 2009 were characterised by fewer calves and old individuals, a reduced number of adult males relative to adult females, and a lower ratio of calves to adult females within groups. We also found a higher proportion of tuskless individuals in poached populations (>6%). Changes in age structure in the Ruaha population between 2009 and 15 were similar to those observed across sites in 2009. Our findings are consistent with previous work documenting how the loss of older individuals – targeted for their larger tusks – decreases recruitment and survival of elephant calves. Illegal killing for ivory is a huge threat to the survival of African elephants. In this context, the present study contributes towards validating the use of age structure as an indicator of poaching pressure in elephant populations, but also in other wildlife populations where illegal offtake is targeted at specific age classes

Investigation of the effect of poaching on African elephant (Loxodonta africana) group size and composition in Ruaha National Park, Tanzania

Monitoring the impacts of poaching on wildlife is crucial to the management of ecosystems and wildlife populations. Previous studies have shown that poaching can affect the demography, reproduction and behavior of wildlife. For African elephants (Loxodonta africana), poaching has been shown to affect population numbers, structure, breeding system, behavior and activity patterns. This study investigated whether there were significant differences in group size and composition of African elephants in Ruaha National Park, Tanzania between areas of high- and low poaching levels, based on the 2013 whole-ecosystem aerial census, which we used as a proxy for poaching pressure. Elephant group size and composition were recorded along 417.6 km of monthly transects from May to November 2016, and again from May to November 2017. Comparison of cow/calf group sizes revealed that the group sizes were larger in areas with low poaching pressure. The dependent-to-adult female ratio was higher in areas with low poaching pressure, while the proportion of adult females was higher in areas with high poaching pressure. The proportions of cow/calf and mixed group types were higher in areas with low poaching pressure. A higher proportion of bull groups were seen in areas with high poaching pressure, which could be evidence of a risk response strategy. Therefore, poaching has significantly shaped grouping patterns, composition and has caused reproductive suppression in Ruaha elephants. We recommend a genetic study of this elephant population to establish the degree of relatedness among families to understand the extent of social structure breakdown caused by social stress due to high poaching pressure in the past years

Spotted hyaena population density across habitat and land use types in southern Tanzania

Although the spotted hyaena (Crocuta crocuta) has been widely considered to be resilient to human disturbance, the species is now thought to be undergoing widespread population declines. Nevertheless, only a handful of population density estimates are available for the species, despite the importance of this information for informing conservation management. This is a consequence of both a lack of surveys and logistical challenges associated with processing spotted hyaena data. In this study, we collaborated with a cohort of students to process camera trap data from the Ruaha-Rungwa landscape initially collected to estimate lion (Panthera leo) and leopard (Panthera pardus) population density. By doing so, we provide the first spatially explicit population density estimates for spotted hyaena in Tanzania, via spatially explicit capture-recapture (SECR) modelling. We also examine the relationship between population densities of spotted hyaena, lion and leopard at each site. Spotted hyaena densities varied from 3.55 ± 0.72 adults and sub-adults per 100 km2 in a miombo (Brachystegia-Julbernardia) woodland area of Ruaha National Park, to 10.80 ± 1.08 per 100 km2 in a prey-rich open woodland savannah habitat in Ruaha National Park, with intermediate densities recorded in Rungwa Game Reserve and MBOMIPA Wildlife Management Area. Our results suggest that spotted hyaena density is influenced by prey availability and protection, and the species may be less resilient to human pressures than widely thought. Spotted hyaena densities were generally positively correlated with densities of lion and leopard, suggesting that prey availability and anthropogenic disturbance had a greater impact than interspecific effects in shaping large carnivore densities in this system. Overall, our study provides some of the first insights into an under-studied species in an under-researched part of its range, while shedding light into the impact of anthropogenic versus interspecific effects in shaping population status of spotted hyaena in human-impacted African systems

Camera trapping and spatially explicit capture–recapture for the monitoring and conservation management of lions: Insights from a globally important population in Tanzania

1. Accurate and precise estimates of population status are required to inform and evaluate conservation management and policy interventions. Although the lion (Panthera leo) is a charismatic species receiving increased conservation attention, robust status estimates are lacking for most populations. While for many large carnivores population density is often estimated through spatially explicit capture–recapture (SECR) applied to camera trap data, the lack of pelage patterns in lions has limited the application of this technique to the species. 2. Here, we present one of the first applications of this methodology to lion, in Tanzania's Ruaha-Rungwa landscape, a stronghold for the species for which no empirical estimates of status are available. We deployed four camera trap grids across habitat and land management types, and we identified individual lions through whisker spots, scars and marks, and multiple additional features. 3. Double-blind identification revealed low inter-observer variation in photo identification (92% agreement), due to the use of xenon-flash cameras and consistent framing and angles of photographs. 4. Lion occurred at highest densities in a prey-rich area of Ruaha National Park (6.12 ± SE 0.94 per 100 km2), and at relatively high densities (4.06 ± SE 1.03 per 100 km2) in a community-managed area of similar riparian-grassland habitat. Miombo woodland in both photographic and trophy hunting areas sustained intermediate lion densities (1.75 ± SE 0.62 and 2.25 ± SE 0.52 per 100 km2, respectively). These are the first spatially explicit density estimates for lion in Tanzania, including the first for a trophy hunting and a community-managed area, and also provide some of the first insights into lion status in understudied miombo habitats. 5. We discuss in detail the methodology employed, the potential for scaling-up over larger areas, and its limitations. We suggest that the method can be an important tool for lion monitoring and explore the implications of our findings for lion management

Analysis and comparison of clinical practice guidelines regarding treatment recommendations for chronic tinnitus in adults: a systematic review

OBJECTIVES: To determine if, and to what extent, published clinical practice guidelines for the treatment of chronic tinnitus vary in their recommendations. DESIGN: Systematic review of guidelines. DATA SOURCES: PubMed, EMBASE and GIN electronic databases were searched in March 2022 and the search was updated in June 2023. ELIGIBILITY CRITERIA: We included clinical practice guidelines that gave recommendations on the treatment of tinnitus. No language restrictions were applied. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted the data and used the AGREE checklist to report on reporting. RESULTS: A total of 10 guidelines were identified and included, published between 2011 and 2021. Recommendations for 13 types of tinnitus treatments were compared. Large differences in guideline development and methodology were found. Seven of the 10 guidelines included a systematic search of the literature to identify the available evidence. Six of the 10 guidelines used a framework for the development of the guideline. Reporting was poor in multiple guidelines. Counselling and cognitive behavioural therapy were the only treatments that were recommended for treating tinnitus associated distress by all guidelines that reported on these topics. Tinnitus retraining therapy, sound therapy, hearing aids and cochlear implantation were not unanimously recommended either due to the lack of evidence, a high risk of bias or judgement of no beneficial effect of the specific treatment. CONCLUSIONS: There were notable differences with respect to whether guidelines considered the available evidence sufficient enough to make a recommendation. Notably, we identified substantial differences in the rigour of guideline design and development. Reporting was poor in many guidelines. Future guidelines could benefit from the use of reporting tools to improve reporting and transparency and the inclusion of guideline experts and patients to improve the quality of clinical practice guidelines on tinnitus

Density responses of lesser-studied carnivores to habitat and management strategies in southern Tanzania's Ruaha-Rungwa landscape

Compared to emblematic large carnivores, most species of the order Carnivora receive little conservation attention despite increasing anthropogenic pressure and poor understanding of their status across much of their range. We employed systematic camera trapping and spatially explicit capture-recapture modelling to estimate variation in population density of serval, striped hyaena and aardwolf across the mixed-use Ruaha-Rungwa landscape in southern Tanzania. We selected three sites representative of different habitat types, management strategies, and levels of anthropogenic pressure: Ruaha National Park’s core tourist area, dominated by Acacia-Commiphora bushlands and thickets; the Park’s miombo woodland; and the neighbouring community-run MBOMIPA Wildlife Management Area, also covered in Acacia-Commiphora. The Park’s miombo woodlands supported a higher serval density (5.56 [Standard Error = ±2.45] individuals per 100 km2) than either the core tourist area (3.45 [±1.04] individuals per 100 km2) or the Wildlife Management Area (2.08 [±0.74] individuals per 100 km2). Taken together, precipitation, the abundance of apex predators, and the level of anthropogenic pressure likely drive such variation. Striped hyaena were detected only in the Wildlife Management Area and at low density (1.36 [±0.50] individuals per 100 km2), potentially due to the location of the surveyed sites at the edge of the species’ global range, high densities of sympatric competitors, and anthropogenic edge effects. Finally, aardwolf were captured in both the Park’s core tourist area and the Wildlife Management Area, with a higher density in the Wildlife Management Area (13.25 [±2.48] versus 9.19 [±1.66] individuals per 100 km2), possibly as a result of lower intraguild predation and late fire outbreaks in the area surveyed. By shedding light on three understudied African carnivore species, this study highlights the importance of miombo woodland conservation and community-managed conservation, as well as the value of by-catch camera trap data to improve ecological knowledge of lesser-studied carnivores