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Grönemann, C. (2015). Konfliktfeld Pferd und Wolf – Eine Untersuchung zu Einstellungen, Erwartungen und Befürchtungen von Pferdehaltern und Reitsportlern in Niedersachsen. Master's thesis, Universität Hildesheim, Hildesheim.
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Burton, A. C., Neilson, E., Moreira, D., Ladle, A., Steenweg, R., Fisher, J. T., et al. (2015). REVIEW: Wildlife camera trapping: a review and recommendations for linking surveys to ecological processes. J Appl Ecol, 52(3), 675–685.
Abstract: Summary Reliable assessment of animal populations is a long-standing challenge in wildlife ecology. Technological advances have led to widespread adoption of camera traps (CTs) to survey wildlife distribution, abundance and behaviour. As for any wildlife survey method, camera trapping must contend with sources of sampling error such as imperfect detection. Early applications focused on density estimation of naturally marked species, but there is growing interest in broad-scale CT surveys of unmarked populations and communities. Nevertheless, inferences based on detection indices are controversial, and the suitability of alternatives such as occupancy estimation is debatable. We reviewed 266 CT studies published between 2008 and 2013. We recorded study objectives and methodologies, evaluating the consistency of CT protocols and sampling designs, the extent to which CT surveys considered sampling error, and the linkages between analytical assumptions and species ecology. Nearly two-thirds of studies surveyed more than one species, and a majority used response variables that ignored imperfect detection (e.g. presence?absence, relative abundance). Many studies used opportunistic sampling and did not explicitly report details of sampling design and camera deployment that could affect conclusions. Most studies estimating density used capture?recapture methods on marked species, with spatially explicit methods becoming more prominent. Few studies estimated density for unmarked species, focusing instead on occupancy modelling or measures of relative abundance. While occupancy studies estimated detectability, most did not explicitly define key components of the modelling framework (e.g. a site) or discuss potential violations of model assumptions (e.g. site closure). Studies using relative abundance relied on assumptions of equal detectability, and most did not explicitly define expected relationships between measured responses and underlying ecological processes (e.g. animal abundance and movement). Synthesis and applications. The rapid adoption of camera traps represents an exciting transition in wildlife survey methodology. We remain optimistic about the technology's promise, but call for more explicit consideration of underlying processes of animal abundance, movement and detection by cameras, including more thorough reporting of methodological details and assumptions. Such transparency will facilitate efforts to evaluate and improve the reliability of camera trap surveys, ultimately leading to stronger inferences and helping to meet modern needs for effective ecological inquiry and biodiversity monitoring.
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Meek, P. D., Ballard, G. - A., & Fleming, P. J. S. (2015). The pitfalls of wildlife camera trapping as a survey tool in Australia. Aust. Mammal., 37(1), 13–22.
Abstract: Camera trapping is a relatively new addition to the wildlife survey repertoire in Australia. Its rapid adoption has been unparalleled in ecological science, but objective evaluation of camera traps and their application has not kept pace. With the aim of motivating practitioners to think more about selection and deployment of camera trap models in relation to research goals, we reviewed Australian camera trapping studies to determine how camera traps have been used and how their technological constraints may have affected reported results and conclusions. In the 54 camera trapping articles published between 1991 and 2013, mammals (86%) were studied more than birds (10%) and reptiles (3%), with small to medium-sized mammals being most studied. Australian camera trapping studies, like those elsewhere, have changed from more qualitative to more complex quantitative investigations. However, we found that camera trap constraints and limitations were rarely acknowledged, and we identified eight key issues requiring consideration and further research. These are: camera model, camera detection system, camera placement and orientation, triggering and recovery, camera trap settings, temperature differentials, species identification and behavioural responses of the animals to the cameras. In particular, alterations to animal behaviour by camera traps potentially have enormous influence on data quality, reliability and interpretation. The key issues were not considered in most Australian camera trap papers and require further study to better understand the factors that influence the analysis and interpretation of camera trap data and improve experimental design.
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Moon, C., Baldridge, M. T., Wallace, M. A., Burnham, C. - A. D., Virgin, H. W., & Stappenbeck, T. S. (2015). Vertically transmitted faecal IgA levels determine extra-chromosomal phenotypic variation. Nature, 521(7550), 90–93.
Abstract: The proliferation of genetically modified mouse models has exposed phenotypic variation between investigators and institutions that has been challenging to control1-5. In many cases, the microbiota is the presumed culprit of the variation. Current solutions to account for phenotypic variability include littermate and maternal controls or defined microbial consortia in gnotobiotic mice6,7. In conventionally raised mice, the microbiome is transmitted from the dam2,8,9. Here we show that microbially–driven dichotomous fecal IgA levels in WT mice within the same facility mimic the effects of chromosomal mutations. We observed in multiple facilities that vertically-transmissible bacteria in IgA-Low mice dominantly lowered fecal IgA levels in IgA-High mice after cohousing or fecal transplantation. In response to injury, IgA-Low mice showed increased damage that was transferable by fecal transplantation and driven by fecal IgA differences. We found that bacteria from IgA-Low mice degraded the secretory component (SC) of SIgA as well as IgA itself. These data indicate that phenotypic comparisons between mice must take into account the non-chromosomal hereditary variation between different breeders. We propose fecal IgA as one marker of microbial variability and conclude that cohousing and/or fecal transplantation enables analysis of progeny from different dams.
Keywords: Phenotype
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Hintze, S., Smith, S., Patt, A., Bachmann, I., & Würbel, H. (2015). What eye wrinkles in horses tell us about their emotional state. In Proceedings of the 3. International Equine Science Meeting.
Abstract: Wrinkles above the eye ball are common in domestic horses but may differ in number and shape both between and within individuals. They are caused by contraction of the inner eye brow raiser, and some people working with horses call them “worry wrinkles”, considering them to reflect emotional states. However, as yet no study has formally investigated the relationship between eye wrinkles and emotional state in horses.
The aim of the present study was to induce states of different emotional valence and to assess whether positive emotional states would reduce the expression of eye wrinkles while negative emotional states would increase it. Sixteen horses were confronted in a balanced order with two presumably positively and two negatively valenced situations each. Positive situations included anticipation of a food reward (FA) and petting (P), negative situations included food competition (FC) and waving a plastic bag (PB). Each situation lasted for 60s (TRT) and was preceded by a 60s control phase (CON). Throughout CON and TRT pictures of the eyes were taken, and for each horse four pictures per situation (FA, P, FC, PB) and phase (CON and TRT) were randomly selected (n = 512) and scored in random order and blind to treatment for six outcome variables: overall impression (qualitative), number, angle and markedness of eye wrinkles, presence of eye white, and shape of eye lid. Data were analysed separately for the right and left eye using linear mixed effects models (angle, number), generalised linear mixed models (eye white, markedness), and ordered logistic regression (qualitative, shape of eye lid), with “situation” (FA, P, FC, PB), “phase” (CON, TRT) and their two-way interaction as fixed effects. Expression of eye wrinkles did not vary consistently across “situation” and “phase”. Independent of phase, eye white appeared less frequently during P than during FA (z=-3.15, p=0.009), FC (z=-2.94, p=0.02), and PB (z=4.17, p<0.001) in the left eye and during PB (z=4.10, p 0.001) in the right eye. Similarly, wrinkles were less marked during P compared to the other situations in the left eye (FA: z=3.15, p=0.009; FC: z=-2.94, p=0.017; PB: z=4.17, p<0.001) and compared to PB in the right eye (z=4.10, p=0.001), while no differences between situations occurred in number of wrinkles, overall impression and shape of eye lid for both eyes. Consistent with our hypothesis, P induced relaxation of the underlying muscle in the right eye resulting in a wider angle compared to its control phase (interaction situation*phase: F3,10=3.71, p=0.055; post-hoc comparison: z=-3.57, p=0.009), while FC induced muscle contraction, resulting in a sharper angle in the left eye (interaction situation*phase: F3,11=6.57, p=0.011; z=3.73, p=0.005). We conclude that emotional valence may affect characteristics of eye winkle expression in horses which might therefore be a promising indicator of horses’ emotional states, but further research is needed to validate the relevant outcome variables. |
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Briefer Freymond, S., Piovesana, L., Briefer. E. F., Beuret. S., Zuberbühler, K., Bshary, R., et al. (2015). Crib-biting behaviour of horses: stress and learning capacity. In Proceedings of the 3. International Equine Science Meeting.
Abstract: Crib-biting is a stereotypy in horses that is potentially linked to both chronic stress and genetic predisposition. Chronic stress can cause neurobiological changes such as alteration of the dopaminergic modulation of the basal ganglia [1]. These neurobiological changes could alter and modify the learning profile of the horses [2,3]. We tested 19 crib-biters and 18 non-crib-biting horses (controls) in five challenging spatial tasks, in order to test if differences in dopaminergic modulation impair learning capacities. The tests were performed in two time periods, in a small arena (8 x 10 m) that was familiar to the horses. For each trials, the horses were led to the start zone in front of a four-meter-long solid fence and were then left alone in the arena. Their task was then to find a bucket containing food, which was situated in different positions around the fence, depending on the tests. The time to reach the food bucket, the trajectory taken by the horse (left or right side of the fence) and the ECG trace were recorded continuously. Additionally, salivary cortisol was collected before the tests (baseline), after the first time period, and after the second time period. We found that crib-biters and controls behaved similarly during the learning tasks. However crib-biters that did crib-bite on the solid fence during the task (group A; 10 horses) behaved differently than crib-biters that did not crib-bite (group B; 9 horses) and controls (group C; 18 horses) for some tests, in their trajectory or time to reach the bucket. These differences are more likely explained by the time taken to crib-bite, than by differences in learning capacity. We did not find any difference between groups in their heart-rate variability (RMSSD). Yet, we found a difference in salivary cortisol after the first time period between groups A, B and C. Indeed, the crib-biters that did not crib-bite had higher salivary cortisol values than all the other horses (mean±SE: A, 0.51±0.16ng/ml, B, 0.78±0.17ng/ml, C, 0.59±0.20ng/ml; Linear mixed model (LMM), p<0.05). Our results suggest that crib-biting horses that did not crib-bite during the learning tasks were more stressed than all other horses. This difference could be due to higher stress sensitivity in crib-biters, which could be reduced by the opportunity to crib-bite. These results replicate our previous findings testing differences in cortisol levels between crib-biters and control horses during an ACTH challenge test. Therefore, crib-biting behaviour might be a coping strategy helping stereotypic horses to reduce their stress during frustrating situations [4].
Keyword: stereotypy, chronic stress, learning task |