Kobayashi, K., Jackowiak, H., Frackowiak, H., Yoshimura, K., Kumakura, M., & Kobayashi, K. (2005). Comparative morphological study on the tongue and lingual papillae of horses (Perissodactyla) and selected ruminantia (Artiodactyla). Ital J Anat Embryol, 110(2 Suppl 1), 55–63.
Abstract: A common characteristic of horses, Rocky Mountain goats, and cattle is that they all have a well developed lingual prominence on the dorsal surface of the posterior area of the tongue. Foliate papillae were found in the horse studied but not in the goat or in cattle. The horse filiform papillae had a long and slender external form with a thin and slender CTC, while in the goat and cattle the external form consisted of a large thick main process and the CTC consisted of a bundle of numerous rod-shaped protrusions. The special papilla found on the lingual prominence resembled larger filiform-like papillae in the horses; however, in the goat and cattle it was a very thick and large tongue like papillae. The horses had two large vallate papillae, while the goat and cattle had 15 or more vallate papillae at the posterior area of the lingual prominence. This suggests that the fine structure of horse tongues may display a more primitive pattern than that present in goats and cattle.
|
Robbins, M. M., Robbins, A. M., Gerald-Steklis, N., & Steklis, H. D. (2005). Long-term dominance relationships in female mountain gorillas: strength, stability and determinants of rank. Behaviour, 142(6), 779–809.
Abstract: A common practice in studies of social animals is to rank individuals according to dominance status, which has been shown to influence access to limited resources and stability of social relationships, and may in turn correlate with reproductive success. According to the socioecological model for primates, most female dominance relationships are either nepotistic or virtually undetectable (egalitarian), with nepotistic species being philopatric, and dispersing females being egalitarian. Female mountain gorillas (Gorilla beringei beringei) disperse, and they have been characterized as being egalitarian, but previous studies have not examined their dominance relationships from a long-term perspective. We evaluated 15 matrices of displacement/supplantation interactions that spanned 30 years of observations in the Virunga Volcanoes region, and included 51 female mountain gorillas in six groups. Only 4% of displacements were directed against higher ranking females, and when matrices had less than 5% unknown dyads, linearity indices were consistently greater than 0.95. Therefore, previous results suggesting undetectable dominance relationships may have reflected an insufficient quantity of data for this species, rather than actual nonlinearity in its hierarchies. Dominance depended on age and group tenure rather than nepotism, yet some females maintained a high ranking for most of adulthood (15-25 years). Most rank shifts occurred through changes in group composition, rather than switches in established relationships. These results fit within growing evidence for linear individualistic hierarchies in some primates, often coupled with dispersal, as commonly found in ungulates. In light of these results, we propose that the dominance relationships of female mountain gorilla are best characterized as “Dispersal-Individualistic” instead of the previously suggested “Dispersal-Egalitarian”.
|
Cooper, M. A., Berntein, I. S., & Hemelrijk, C. K. (2005). Reconciliation and relationship quality in Assamese macaques (Macaca assamensis). Am. J. Primatol., 65(3), 269–282.
Abstract: A consistent conclusion in reconciliation research is that animals that reconcile are likely to have strong social bonds. This has led to the hypothesis that reconciliation occurs most often between valuable social partners. We tested this hypothesis in a group of Assamese macaques (Macaca assamensis) living near a temple in Assam, India. Using focal sample and ad libitum data collection, we recorded the occurrence of reconciliation, grooming, and agonistic aiding, and the outcomes of approach. We used matrix association methods (TauKr correlation) to correlate reconciliation with grooming, aiding, and approach outcome. Females reconciled more often with females with which they had stronger grooming and aiding relationships. The correlation between reconciliation and aiding was significant for support to the aggressor and the victim. In contrast, no such correlations with reconciliation were found for males. This study provides evidence that females reconcile most often with valuable and compatible social partners. The results do not support the relationship-quality hypothesis for males, and we suggest that future studies give more consideration to the possibility that males reconcile for reasons other than to repair relationships with valuable partners.
|
Palme, R., Rettenbacher, S., Touma, C., El-Bahr, S. M., & Mostl, E. (2005). Stress hormones in mammals and birds: comparative aspects regarding metabolism, excretion, and noninvasive measurement in fecal samples. Ann N Y Acad Sci, 1040, 162–171.
Abstract: A multitude of endocrine mechanisms are involved in coping with challenges. Front-line hormones to overcome stressful situations are glucocorticoids (GCs) and catecholamines (CAs). These hormones are usually determined in plasma samples as parameters of adrenal activity and thus of disturbance. GCs (and CAs) are extensively metabolized and excreted afterwards. Therefore, the concentration of GCs (or their metabolites) can be measured in various body fluids or excreta. Above all, fecal samples offer the advantages of easy collection and a feedback-free sampling procedure. However, large differences exist among species regarding the route and time course of excretion, as well as the types of metabolites formed. Based on information gained from radiometabolism studies (reviewed in this paper), we recently developed and successfully validated different enzyme immunoassays that enable the noninvasive measurement of groups of cortisol or corticosterone metabolites in animal feces. The determination of these metabolites in fecal samples can be used as a powerful tool to monitor GC production in various species of domestic, wildlife, and laboratory animals.
|
Grogan, E. H., & McDonnell, S. M. (2005). Mare and Foal Bonding and Problems. Clinical Techniques in Equine Practice, 4(3), 228–237.
Abstract: A number of specific behavioral responses have been identified in mares and foals as the presumed behavioral interactive sequences supporting bonding. With the exception of the severely physically compromised foal, most failures of the mare foal bond appear to result from inadequate behavior of the mare. Six distinct forms of maternal behavior problems include ambivalence of the mare toward her foal, fear of the foal, nursing only avoidance of the foal, extreme protectiveness of the foal that becomes problematic in domestic confinement, savage attack (true rejection), and stealing or adoption of an alien foal. Management of maternal behavior problem cases in which the pair cannot be salvaged include foster (or nurse mares) and hand-rearing methods. Also presented are current practical resources related to managing certain types of inadequate maternal behavior and for rearing the orphaned foal.
|
Lamoot, I., Callebaut, J., Demeulenaere, E., Vandenberghe, C., & Hoffmann, M. (2005). Foraging behaviour of donkeys grazing in a coastal dune area in temperate climate conditions. Appl. Anim. Behav. Sci., 92(1-2), 93–112.
Abstract: A small herd of donkeys was introduced in a coastal dune reserve `Houtsaegerduinen' (ca. 80 ha) in Belgium, in order to slow down expansion of dominant grass and shrub species. The Houtsaegerduinen is a nutrient poor scrub-dominated dune system with a spatially heterogeneous vegetation pattern. Different aspects of the grazing behaviour (grazing time, bite rate, habitat use, diet composition) of the free-ranging donkeys are described and analysed. Behavioural data (of maximum six adult mares) were collected through continuous focal animal observation in three consecutive years (1998-2001). Temporal variation in grazing time, habitat use and diet composition was determined. During daylight, donkeys spent most of their time on grazing (56%). In all 3 years, grazing time was significantly shorter in summer (45% of their time), longest grazing times were achieved in spring (64%). In spring, the donkeys also achieved the highest bite rate (21.5 bites/min). The grassy habitat was preferred for foraging in all seasons, while the use of scrub and woodland was variable over time. Averaged over the four seasons, the general diet consisted for 80% of graminoids, 10% of forbs and 10% of woody plants. However, diet composition varied not only among seasons and years, but depended also on the foraged habitat type. We discuss the possible role of the donkeys in nature management.
|
Lewis, K. P., Jaffe, S., & Brannon, E. M. (2005). Analog number representations in mongoose lemurs (Eulemur mongoz): evidence from a search task. Anim. Cogn., 8(4), 247–252.
Abstract: A wealth of data demonstrating that monkeys and apes represent number have been interpreted as suggesting that sensitivity to number emerged early in primate evolution, if not before. Here we examine the numerical capacities of the mongoose lemur (Eulemur mongoz), a member of the prosimian suborder of primates that split from the common ancestor of monkeys, apes and humans approximately 47-54 million years ago. Subjects observed as an experimenter sequentially placed grapes into an opaque bucket. On half of the trials the experimenter placed a subset of the grapes into a false bottom such that they were inaccessible to the lemur. The critical question was whether lemurs would spend more time searching the bucket when food should have remained in the bucket, compared to when they had retrieved all of the food. We found that the amount of time lemurs spent searching was indicative of whether grapes should have remained in the bucket, and furthermore that lemur search time reliably differentiated numerosities that differed by a 1:2 ratio, but not those that differed by a 2:3 or 3:4 ratio. Finally, two control conditions determined that lemurs represented the number of food items, and neither the odor of the grapes, nor the amount of grape (e.g., area) in the bucket. These results suggest that mongoose lemurs have numerical representations that are modulated by Weber's Law.
|
Huebener, E. (2005). Rider's Aids for Transitions Between Different Gaits ? The Movements of the Horse's Trunk and Back as Timers for the Rider's Influence. Trakehner Hefte, 5-11.
Abstract: Abstract
According to Ludwig Koch, the horse's transition from one gait to another is only possible during a particular phase in its' movement cycle (respectively in a half of it's movement cycle) in one gait to a particular phase in its' movement cycle (respectively in a half of it's movement cycle) in the other gait.
It only takes a fraction of a second for these movements to occur. It is precisely in these moments that according to the European classical riding school principles the rider has to give the appropriate aids, because only then the horse can execute them in a flash. In order to give the aids in the “fitting” moment, the rider needs a timer. The only available and reliable indicators of the right timing are the movements of the horse's trunk and back.
The connections between the different phases of the movements during the basic gaits, the rider's seat which follows all the movements of the horse's back with a freely rotating pelvis, and the rider's leg which – from step to step, from footfall to footfall, from canter beat to canter beat – wants to follow the horse's swinging trunk (until it is finally – controlled by the rider – free to do so, at the right moment), are being shown for the first time in easy to follow miniature picture sequences.
|
Galef, B. G., & Laland, K. N. (2005). Social Learning in Animals: Empirical Studies and Theoretical Models. BioScience, 55(6), 489–499.
Abstract: AbstractThe last two decades have seen a virtual explosion in empirical research on the role of social interactions in the development of animals' behavioral repertoires, and a similar increase in attention to formal models of social learning. Here we first review recent empirical evidence of social influences on food choice, tool use, patterns of movement, predator avoidance, mate choice, and courtship, and then consider formal models of when animals choose to copy behavior, and which other animals' behavior they copy, together with empirical tests of predictions from those models.
|
König, H. E., Wissdorf, H., Probst, A., Macher, R., Voß, S., & Polsterer, E. (2005). Considerations about the function of the mimic muscles and the vomeronasal organ of horses during the Flehmen reaction. Pferdeheilkunde, 21(4), 297–300.
Abstract: Additional to the olfactory epithelium, the equine vomeronasal organ serves to the perception of odorous substances and specially for pheromones. In a middle-size horse this organ has an extension in length from an imaginary transverse plane about 10 cm caudally the nostrils to a transverse plane through the middle of the second premolar tooth. During the Flehmen reaction the levator labii superior, nasolabial, caninus and lateralis nasi muscles contract. The upper lip and the tip of the nose are lifted. The opening of the nostrils is narrowed, caused by the convergence of the plate and horn of the alar cartilage. In this manner in case of Flehmen reaction air is directly conducted towards the opening of the vomeronasal organ into the nasal cavity during inspiration. During the “Flehmen” horses assume a characteristic posture.
|
