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Gholib, G., Heistermann, M., Agil, M., Supriatna, I., Purwantara, B., Nugraha, T. P., et al. (2018). Comparison of fecal preservation and extraction methods for steroid hormone metabolite analysis in wild crested macaques. Primates, 59(3), 281–292.
Abstract: Since the non-invasive field endocrinology techniques were developed, several fecal preservation and extraction methods have been established for a variety of species. However, direct adaptation of methods from previous studies for use in crested macaques should be taken with caution. We conducted an experiment to assess the accuracy and stability of fecal estrogen metabolite (E1C) and glucocorticoid metabolite (GCM) concentrations in response to several preservation parameters: (1) time lag between sample collection and fecal preservation; (2) long-term storage of fecal samples in 80% methanol (MeOH) at ambient temperature; (3) different degrees of feces drying temperature using a conventional oven; and (4) different fecal preservation techniques (i.e., freeze-drying, oven-drying, and field-friendly extraction method) and extraction solvents (methanol, ethanol, and commercial alcohol). The study used fecal samples collected from crested macaques (Macaca nigra) living in the Tangkoko Reserve, North Sulawesi, Indonesia. Samples were assayed using validated E1C and GCM enzyme immunoassays. Concentrations of E1C and GCM in unprocessed feces stored at ambient temperature remained stable for up to 8 h of storage after which concentrations of both E1C and GCM changed significantly compared to controls extracted at time 0. Long-term storage in 80% MeOH at ambient temperature affected hormone concentrations significantly with concentrations of both E1C and GCM increasing after 6 and 4 months of storage, respectively. Drying fecal samples using a conventional oven at 50, 70, and 90 °C did not affect the E1C concentrations, but led to a significant decline for GCM concentrations in samples dried at 90 °C. Different fecal preservation techniques and extraction solvents provided similar results for both E1C and GCM concentrations. Our results confirm previous studies that prior to application of fecal hormone analysis in a new species, several preservation parameters should be evaluated for their effects on hormone metabolite stability. The results also provide several options for fecal preservation, extraction, and storage methods that can be selected depending on the condition of the field site and laboratory.
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Bonin, S. J., Clayton, H. M., Lanovaz, J. L., & Johnston, T. (2007). Comparison of mandibular motion in horses chewing hay and pellets. Equine Vet. J., 39(3), 258–262.
Abstract: Summary Reasons for performing study: Previous studies have suggested that temporomandibular joint (TMJ) kinematics depend on the type of food being masticated, but accurate measurements of TMJ motion in horses chewing different feeds have not been published. Hypothesis: The temporomandibular joint has a larger range of motion when horses chew hay compared to pellets. Methods: An optical motion capture system was used to track skin markers on the skull and mandible of 7 horses as they chewed hay and pellets. A virtual marker was created on the midline between the mandibles at the level of the 4th premolar teeth to represent the overall motion of the mandible relative to the skull during the chewing cycle. Results: Frequency of the chewing cycles was lower for hay than for pellets. Excursions of the virtual mandibular marker were significantly larger in all 3 directions when chewing hay compared to pellets. The mean velocity of the virtual mandibular marker during the chewing cycle was the same when chewing the 2 feeds. Conclusions: The range of mediolateral displacement of the mandible was sufficient to give full occlusal contact of the upper and lower dental arcades when chewing hay but not when chewing pellets. Potential relevance: These findings support the suggestion that horses receiving a diet high in concentrate feeds may require more frequent dental prophylactic examinations and treatments to avoid the development of dental irregularities associated with smaller mandibular excursions during chewing.
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Morgan, T. W., & Elliott, C. L. (2011). Comparison of remotely-triggered cameras vs. howling surveys for estimating coyote (Canis latrans) Abundance in central Kentucky. J Ky Acad Science, 72.
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Clayton, H. M., Hampson, A., Fraser, P., White, A., & Egenvall, A. (2018). Comparison of rider stability in a flapless saddle versus a conventional saddle. Plos One, 13(6), e0196960.
Abstract: The purpose of a saddle is to improve the rider's safety, security, and comfort, while distributing the forces exerted by the rider and saddle over a large area of the horse's back without focal pressure points. This study investigates the effects on rider stability of an innovative saddle design that differs from a conventional saddle in having no flaps. Five horses were ridden by their regular rider in their usual saddle and in a flapless saddle. A pressure mat (60 Hz) placed between the saddle and the horse's back was used to determine the position of the center of pressure, which represents the centroid of pressure distribution on the horse's back. Data were recorded as five horses were ridden at collected and extended walk, trot and canter in a straight line. Data strings were split into strides with 5 strides analysed per horse/gait/type. For each stride the path of the rider's center of pressure was plotted, maximal and minimal values in the anteroposterior and mediolateral directions were extracted, and ranges of motion in anteroposterior and mediolateral directions were calculated. Differences between the conventional and flapless saddles were analysed using mixed models ANOVA. Speed and stride length of each gait did not differ between saddles. Compared with the conventional saddle, the flapless saddle was associated with significant reductions in range of motion of the rider's center of pressure in the mediolateral direction in all gaits and in the anteroposterior direction in collected trot, extended trot and extended canter. The improved stability was thought to result from the absence of saddle flaps allowing the rider's thighs to lie in more adducted positions, which facilitated the action of the lumbopelvic-hip musculature in stabilizing and controlling translations and rotations of the pelvis and trunk. The closer contact between rider and horse may also have augmented the transfer of haptic information.
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Werhahn, H., Hessel, E. F., & Van den Weghe, H. F. A. (2012). Competition Horses Housed in Single Stalls (II): Effects of Free Exercise on the Behavior in the Stable, the Behavior during Training, and the Degree of Stress. Journal of Equine Veterinary Science, 32(1), 22–31.
Abstract: Although housing horses in single stalls limits their natural behavior to a great extent, this housing system is widespread in Germany, especially for competition horses. To improve the welfare of this system, free exercise on pastures or paddocks is deemed suitable, but it is also feared because of injuries and decreased willingness or motivation to perform. In the present study, three treatments were investigated with regard to their effect on the behavior of six competition horses in the stable, behavior during training, and on their degree of stress: daily training without free exercise (no turnout [NT]), solitary turnout for 2 hours after training, and 2-hour turnout in groups of two after training (group turnout). The horses' behavior in the stable was continuously analyzed through video recordings (2 pm to 6 am) on 3 days at the end of each treatment. The degree of stress was evaluated daily by heart rate variability at rest. The behavior during training was evaluated by a questionnaire answered by the riders, and the distance covered during training was measured by global positioning system. When NT was allowed, the horses showed less lying in the stable compared with the treatments with turnout. Heart rate variability measurements resulted in great individual differences, but generally, there was a higher degree of stress shown with the treatment NT according to the following parameters: standard deviation of inter-beat-intervals (SDNN), square root of the mean of the sum of the squares of differences between successive inter-beat-intervals (RMSSD), and ratio between low frequency and high frequency (LF/HF). The willingness to perform was evaluated as being slightly better in the treatments with turnout than in the treatment without turnout.
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Langbein, J., Siebert, K., & Nuernberg, G. (2008). Concurrent recall of serially learned visual discrimination problems in dwarf goats (Capra hircus). Behav Proc, 79.
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Stanley, C. R., & Dunbar, R. I. M. (2013). Consistent social structure and optimal clique size revealed by social network analysis of feral goats, Capra hircus. Anim Behav, 85.
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van de Waal, E., & Bshary, R. (2010). Contact with human facilities appears to enhance technical skills in wild vervet monkeys (Chlorocebus aethiops). Folia Primatol, 81.
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Van Horik, J., Clayton, N., & Emery, N. (2012). Convergent evolution of cognition in Corvids, Apes and other animals. In J. Vonk, & T. Shackelford (Eds.), Oxford Handbook of Comparative Evolutionary Psychology. New York: Oxford University Press.
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Smolla, M., Alem, S., Chittka, L., & Shultz, S. (2016). Copy-when-uncertain: bumblebees rely on social information when rewards are highly variable. Biol. Lett., 12(6).
Abstract: To understand the relative benefits of social and personal information use in foraging decisions, we developed an agent-based model of social learning that predicts social information should be more adaptive where resources are highly variable and personal information where resources vary little. We tested our predictions with bumblebees and found that foragers relied more on social information when resources were variable than when they were not. We then investigated whether socially salient cues are used preferentially over non-social ones in variable environments. Although bees clearly used social cues in highly variable environments, under the same conditions they did not use non-social cues. These results suggest that bumblebees use a 'copy-when-uncertain' strategy.
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