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Sinclair, M., Buhrmann, G., & Gummow, B. (2006). An epidemiological investigation of the African horsesickness outbreak in the Western Cape Province of South Africa in 2004 and its relevance to the current equine export protocol. J S Afr Vet Assoc, 77(4), 191–196.
Abstract: African Horsesickness (AHS) is a controlled disease in South Africa. The country is divided into an infected area and a control area. An outbreak of AHS in the control area can result in a ban of exports for at least 2 years. A retrospective epidemiological study was carried out on data collected during the 2004 AHS outbreak in the surveillance zone of the AHS control area in the Western Cape Province. The objective of this study was to describe the 2004 outbreak and compare it with the 1999 AHS outbreak in the same area. As part of the investigation, a questionnaire survey was conducted in the 30 km radius surrounding the index case. Spatial, temporal and population patterns for the outbreak are described. The investigation found that the outbreak occurred before any significant rainfall and that the main AHS vector (Culicoides imicola) was present in abundance during the outbreak. Furthermore, 63% of cases occurred at temperatures < or = 15 degrees C, the Eerste River Valley was a high risk area, only 17% of owners used vector protection as a control measure and 70% of horses in the outbreak area were protected by means of vaccination at the start of the outbreak. The study revealed that the current AHS control measures do not function optimally because of the high percentage of vaccinated horses in the surveillance zone, which results in insufficient sentinel animals and the consequent failure of the early warning system. Alternative options for control that allow continued export are discussed in the paper.
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Li, F. - H., Zhong, W. - Q., Wang, Z., & Wang, D. - H. (2007). Rank in a food competition test and humoral immune functions in male Brandt's voles (Lasiopodomys brandtii). Physiol. Behav., 90(2-3), 490–495.
Abstract: Social status can influence an animal's immune and reproductive functions, eventually leading to alterations in immunocompetence and reproductive success. Here, we report that rank assessed in a food competition test, considered as an index of social status, has significant influences on humoral immune functions in male Brandt's voles (Lasiopodomys brandtii) living in a group. Our data reveal a negative correlation of the spleen mass and serum antibody levels with social status, as well as a positive correlation of serum cortisol levels with social status. Males winning in food competition had a smaller spleen, a lower level of serum antibodies, and a higher level of serum cortisol than did their conspecific counterparts. These data indicate interactions between social status and humoral immune functions and might illustrate a trade-off between infection risks and reproductive success in male Brandt's voles.
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Zhou, W. - X., Sornette, D., Hill, R. A., & Dunbar, R. I. M. (2005). Discrete hierarchical organization of social group sizes. Proc Biol Sci, 272(1561), 439–444.
Abstract: The 'social brain hypothesis' for the evolution of large brains in primates has led to evidence for the coevolution of neocortical size and social group sizes, suggesting that there is a cognitive constraint on group size that depends, in some way, on the volume of neural material available for processing and synthesizing information on social relationships. More recently, work on both human and non-human primates has suggested that social groups are often hierarchically structured. We combine data on human grouping patterns in a comprehensive and systematic study. Using fractal analysis, we identify, with high statistical confidence, a discrete hierarchy of group sizes with a preferred scaling ratio close to three: rather than a single or a continuous spectrum of group sizes, humans spontaneously form groups of preferred sizes organized in a geometrical series approximating 3-5, 9-15, 30-45, etc. Such discrete scale invariance could be related to that identified in signatures of herding behaviour in financial markets and might reflect a hierarchical processing of social nearness by human brains.
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Toro, J. M., Trobalon, J. B., & Sebastian-Galles, N. (2003). The use of prosodic cues in language discrimination tasks by rats. Anim. Cogn., 6(2), 131–136.
Abstract: Recent research with cotton-top tamarin monkeys has revealed language discrimination abilities similar to those found in human infants, demonstrating that these perceptual abilities are not unique to humans but are also present in non-human primates. Specifically, tamarins could discriminate forward but not backward sentences of Dutch from Japanese, using both natural and synthesized utterances. The present study was designed as a conceptual replication of the work on tamarins. Results show that rats trained in a discrimination learning task readily discriminate forward, but not backward sentences of Dutch from Japanese; the results are particularly robust for synthetic utterances, a pattern that shows greater parallels with newborns than with tamarins. Our results extend the claims made in the research with tamarins that the capacity to discriminate languages from different rhythmic classes depends on general perceptual abilities that evolved at least as far back as the rodents.
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Xitco, M. J. J., Gory, J. D., & Kuczaj, S. A. 2nd. (2004). Dolphin pointing is linked to the attentional behavior of a receiver. Anim. Cogn., 7(4), 231–238.
Abstract: In 2001, Xitco et al. (Anim Cogn 4:115-123) described spontaneous behaviors in two bottlenose dolphins (Tursiops truncatus) that resembled pointing and gaze alternation. The dolphins' spontaneous behavior was influenced by the presence of a potential receiver, and the distance between the dolphin and the receiver. The present study adapted the technique of Call and Tomasello [(1994) J Comp Psychol 108:307-317], used with orangutans to test the effect of the receiver's orientation on pointing in these same dolphins. The dolphins directed more points and monitoring behavior at receivers whose orientation was consistent with attending to the dolphins. The results demonstrated that the dolphins' pointing and monitoring behavior, like that of apes and infants, was linked to the attentional behavior of the receiver.
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Fragaszy, D. M., & Visalberghi E. (1989). Social influences on the acquisition of tool-using behaviors in tufted capuchin monkeys (Cebus apella). J. Comp. Psychol., 103(2), 159–170.
Abstract: To identify behaviors related to acquisition of tool-use in tufted capuchins (Cebus apella), we presented two tool-using tasks to two groups, extending findings by Westergaard and Fragaszy (1987) and Visalberghi (in press). Five Ss learned to use the tools in each task. The primary predictor of success was level of interest in the task. Observation of others at the apparatus did not facilitate exploratory behaviors or contact with the tools in the observers. Most animals performed exploratory behaviors more often when they were at the apparatus alone than when with another, whether or not the other was using a tool. Observers were quick to learn the relationship between another's activities and the appearance of food. We conclude that capuchins do not readily learn about instrumental relations by observation of others or imitate other's acts. Imitation probably plays no role in the spread of novel instrumental behaviors among monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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Shultz, S. (2012). Are equid brains social? Exploring the evolution of equid social structure and social intelligence. In K. Krueger (Ed.), Proceedings of the 2. International Equine Science Meeting (Vol. in press). Wald: Xenophon Publishing.
Abstract: The living equids display a variety of different forms of social organisation; plains (Equus quagga) and mountain zebra (Equus zebra) associate in small, closed harems, whereas the asses and Grevy’s zebra (Equus grevyi) are found in looser, more ephemeral associations. Feral domestic horses appear to be somewhat intermediate: although stallions generally maintain harems, there is some movement of individuals between groups. This talk will use several statistical approached to explore evolutionary explanations for these differences. Firstly, we will explore the relationship between brain architecture and social organisation both among the equids and across all Perissodactyls. Equids have larger relative neocortices than other Perissodactyls; within the equids, species typically found in more stable groups have larger neocortices than equids in more unstable ephemeral groups. The strong relationship between group stability and brain size and architecture mirrors that found in other mammals, including primates. Thus, living in stable social groups consistently appears to impose cognitive demands across species. In order to understand the historical trajectory resulting in the relatively large, social brains found in some species, we then reconstruct the evolutionary pathway of social living in the equids. Finally, we discuss how we can use network theory to measure social structure and how these differences may impose different cognitive demands on individuals.
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Monfort, S. (2004). Przewalski’s Horse (Equus przewalskii) Species Survival Plan. In PROCEEDINGS OF THE EAZA EQUID TAG MEETING FROM 5TH TO 9TH MAY 2004 AT HORTOBÁGY NATIONAL PARK, HUNGARY.
Abstract: A Master Planning meeting for the Asian wild horse, or Przewalski’s horse, was held 14th –15th April 2004 at the National Zoological Park’s Conservation and Research Center (CRC) in Front Royal, Virginia. The overall objectives of the meeting were to 1) develop a strategy to maximize genetic diversity and improve demographics, 2) make specific breeding recommendations, 3) establish ex situ research priorities, and 4) discuss strategies for ensuring that the North American herd contributes to the global managed population, as well as ongoing in situ conservation programs. Of particular importance were discussions focused on whether to continue managing the North American herd as two separate bloodlines — the A- and B-lines — or to manage the entire population using an M-line, or mixed-line strategy, designed to maximize founder representation and genetic diversity. The Equid Taxon Advisory Group has currently designated a target population of 150 specimens for this species. The current SSP population is 154 individuals distributed among 18 institutions (15 AZA, 3 non-AZA), of which San Diego Zoo, the Wilds, Minnesota Zoo, Calgary Zoo, the Wildlife Conservation Society/Bronx Zoo and the National Zoological Park were represented at the Master Planning meeting.
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Christie, J. L., Hewson, C. J., Riley, C. B., McNiven, M. A., Dohoo, I. R., & Bate, L. A. (2006). Management factors affecting stereotypies and body condition score in nonracing horses in Prince Edward Island. Can Vet J, 47(2), 136–143.
Abstract: In North America, there are few representative data about the effects of management practices on equine welfare. In a randomized survey of 312 nonracing horses in Prince Edward Island (response rate 68.4%), owners completed a pretested questionnaire and a veterinarian examined each horse. Regression analyses identified factors affecting 2 welfare markers: body condition score (BCS) and stereotypic behavior. Horses' BCSs were high (mean 5.7, on a 9-point scale) and were associated with sex (males had lower BCSs than females; P < 0.001) and examination date (P = 0.052). Prevalences of crib biting, wind sucking, and weaving were 3.8%, 3.8%, and 4.8%, respectively. Age (OR = 1.07, P = 0.08) and hours worked weekly (OR = 1.12, P = 0.03) were risk factors for weaving. Straw bedding (OR = 0.3, P = 0.03), daily hours at pasture (OR = 0.94, P = 0.02), and horse type (drafts and miniatures had a lower risk than light horses; P = 0.12) reduced the risk of horses showing oral stereotypies. Some of these results contradict those of other studies perhaps because of populations concerned.
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Shanahan, S. (2003). Trailer loading stress in horses: behavioral and physiological effects of nonaversive training (TTEAM). J Appl Anim Welf Sci, 6(4), 263–274.
Abstract: Resistance in the horse to trailer loading is a common source of stress and injury to horses and their handlers. The objective of this study was to determine whether nonaversive training based on the Tellington-Touch Equine Awareness Method (TTEAM; Tellington-Jones &Bruns, 1988) would decrease loading time and reduce stress during loading for horses with a history of reluctance to load. Ten horses described by their owners as “problem loaders” were subjected to pretraining and posttraining assessments of loading. Each assessment involved two 7-min loading attempts during which heart rate and saliva cortisol were measured. The training consisted of six 30-min sessions over a 2-week period during which the horse and owner participated in basic leading exercises with obstacles simulating aspects of trailering. Assessment showed heart rate and saliva cortisol increased significantly during loading as compared to baseline (p <.001 and p <.05, respectively). Reassessment after training showed a decrease in loading time (p <.02), reduced heart rate during loading (p <.002), and reduced saliva cortisol as compared to pretraining assessments. Seven “good loaders” also were subject to loading assessment for physiological comparison. Increases in heart rate during loading were significantly higher in the good loaders (p <.001). Nonaversive training simulating aspects of loading may effectively reduce loading time and stress during loading for horses with a history of resistance to trailer loading.
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