Abstract: Additional measures of well-being would be beneficial to the management of a variety of species in human care, including elephants. Immunoglobulin A (IgA) is an immune protein associated with pathogen defense, which has been demonstrated to decrease during times of stress, and increase in response to positive stimuli. This paper describes the development and validation of an enzyme immunoassay (EIA) for the quantification of Asian elephant (Elephas maximus) IgA in feces, saliva, urine, and serum. Samples were collected weekly from four females for 6 months to assess IgA and glucocorticoid (GC) concentrations, establish relationships between these two biomarkers, and determine variability in IgA within and between individuals, and across sample types. IgA was quantified in all four sample types, although urinary concentrations were low and sometimes undetectable in individual samples. Concentrations were highly variable within and between individuals, with fecal, salivary and serum IgA, and fecal, salivary and urinary GCs all differing significantly across individuals. Contrary to previous findings, IgA and GC were generally not correlated. Serum IgA was less variable within individuals, with the exception of one female that experienced a brief illness during the study. However, marked inter-individual differences were still apparent. When data from all individuals were combined, fecal IgA was significantly predicted by salivary and urinary IgA; however, this relationship did not hold when individuals were analyzed separately. Analysis of a fifth female that exhibited a more severe systemic illness demonstrated clear increases in fecal IgA and GC, suggesting these may also be useful health biomarkers. Further investigation is needed to determine what sample type is most reflective of biological state in elephants, and how IgA concentrations are associated with health and positive and negative welfare states. Based on observed variability, a longitudinal approach likely will be necessary to use IgA as a measure of well-being.

Abstract: ABSTRACTThe proliferation of relatively affordable off-the-shelf drones offers great opportunities for wildlife monitoring and conservation. Similarly the recent reduction in the cost of thermal infrared cameras also offers new promise in this field, as they have the advantage over conventional RGB cameras of being able to distinguish animals based on their body heat and being able to detect animals at night. However, the use of drone-mounted thermal infrared cameras comes with several technical challenges. In this article, we address some of these issues, namely thermal contrast problems due to heat from the ground, absorption and emission of thermal infrared radiation by the atmosphere, obscuration by vegetation, and optimizing the flying height of drones for a best balance between covering a large area and being able to accurately image and identify animals of interest. We demonstrate the application of these methods with a case study using field data and make the first ever detection of the critically endangered riverine rabbit (Bunolagus monticularis) in thermal infrared data. We provide a web-tool so that the community can easily apply these techniques to other studies (http://www.astro.ljmu.ac.uk/aricburk/uav_calc/).

Abstract: Two brain hemispheres are unequally involved in the processing of social stimuli, as demonstrated in a wide range of vertebrates. A considerable number of studies have shown the right hemisphere advantage for social processing. At the same time, an approach-withdrawal hypothesis, mainly based on experimental evidence, proposes the involvement of both brain hemispheres according to approach and withdrawal motivation. The present study aimed to test the relative roles of the two hemispheres in social responses displayed in a natural context. Visual biases, implicating hemispheric lateralization, were estimated in the social interactions of saiga antelope in the wild. In individually identified males, the left/right visual field use during approach and withdrawal responses was recorded based on the lateral head/body position, relative to the conspecific. Lateralized approach responses were investigated in three types of interactions, with left visual field bias found for chasing a rival, no bias--for attacking a rival, and right visual field bias--for pursuing a female. In two types of withdrawal responses, left visual field bias was found for retreating after fighting, while no bias was evident in fight rejecting. These findings demonstrate that neither the right hemisphere advantage nor the approach-withdrawal distinction can fully explain the patterns of lateralization observed in social behaviour. It is clear that both brain hemispheres play significant roles in social responses, while their relative contribution is likely determined by a complex set of motivational and emotional factors rather than a simple dichotomous distinction such as, for example, approach versus withdrawal motivation.

Abstract: Abstract Obtaining reliable species observations is of great importance in animal ecology and wildlife conservation. An increasing number of studies use camera traps (CTs) to study wildlife communities, and an increasing effort is made to make better use and reuse of the large amounts of data that are produced. It is in these circumstances that it becomes paramount to correct for the species- and study-specific variation in imperfect detection within CTs. We reviewed the literature and used our own experience to compile a list of factors that affect CT detection of animals. We did this within a conceptual framework of six distinct scales separating out the influences of (a) animal characteristics, (b) CT specifications, (c) CT set-up protocols, and (d) environmental variables. We identified 40 factors that can potentially influence the detection of animals by CTs at these six scales. Many of these factors were related to only a few overarching parameters. Most of the animal characteristics scale with body mass and diet type, and most environmental characteristics differ with season or latitude such that remote sensing products like NDVI could be used as a proxy index to capture this variation. Factors that influence detection at the microsite and camera scales are probably the most important in determining CT detection of animals. The type of study and specific research question will determine which factors should be corrected. Corrections can be done by directly adjusting the CT metric of interest or by using covariates in a statistical framework. Our conceptual framework can be used to design better CT studies and help when analyzing CT data. Furthermore, it provides an overview of which factors should be reported in CT studies to make them repeatable, comparable, and their data reusable. This should greatly improve the possibilities for global scale analyses of (reused) CT data.

Abstract: Glucocorticoids (GCs; i.e. cortisol/corticosterone) are a central component of the stress response and thus their measurement is frequently used to evaluate the impact of stressful situations. Their metabolites from faeces of various animal species are more and more taken as a non-invasive aid to assess GC release and thus adrenocortical activity. The current literature review includes an extensive collection (1327 papers) and evaluation (see also Supplementary Tables) of the literature on faecal cortisol/corticosterone metabolite (FCM) analysis published to date. It aims at giving reference for researchers interested in implementing FCM analysis into their study or seeking to improve such methods by providing background knowledge on GC metabolism and excretion, conveying insights into methodological issues and stating caveats of FCM analysis and by highlighting prerequisites for and some examples of a successful application of such methods. Collecting faecal samples and analysing FCMs may appear simple and straightforward, but researchers have to select and apply methods correctly. They also need to be aware of the many pitfalls and potentially confounding factors and, last but not least, have to carefully interpret results. Applied properly, measurement of FCMs is a powerful non-invasive tool in a variety of research areas, such as (stress) biology, ethology, ecology, animal conservation and welfare, but also biomedicine.