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.

Abstract: Our understanding of how, why, and the circumstances under which animals use social information has been facilitated by three principal areas of research, social learning, public information use and social eavesdropping. With few exceptions, these related concepts have remained remarkably distinct within the literature, with little discussion or integration among them. Are these distinctions warranted? We tackle the issue by exploring similarities and differences between the concepts with respect to how animals gather and use social information, the type of information gathered, how information is packaged, and the relative payoffs to individuals involved. We contend that none of the currently dominant paradigms, social learning, public information use, or social eavesdropping, provide a unifying theme for studying social information use. Instead, we favour the central characteristic of the three concepts, social information use, as the overarching umbrella, and advocate a broader conceptual framework for understanding more comprehensively how animals behave with their social environments. Our intention is not to revolutionize the fields of social learning, public information use or social eavesdropping, but rather to stimulate discussion among researchers investigating the abilities of animals to extract information from the social environment.

Abstract: There are numerous reports of novel learned behaviour patterns in animal populations, yet the factors influencing the invention and spread of these innovations remain poorly understood. Here we investigated to what extent the pattern of spread of innovations in captive groups of starlings, Sturnus vulgaris, could be predicted by knowledge of individual and social group variables, including association patterns, social rank orders, measures of neophobia and asocial learning performance. We presented small groups of starlings with a series of novel extractive foraging tasks and recorded the latency for each bird to contact and solve each task, as well as the orders of contacting and solving. We then explored which variables best predicted the observed diffusion patterns. Object neophobia and social rank measures characterized who was the first of the group to contact the novel foraging tasks, and the subsequent spread of contacting tasks was associated with latency to feed in a novel environment. Asocial learning performance, measured in isolation, predicted who was the first solver of the novel foraging tasks in each group. Association patterns did not predict the spread of solving. Contact latency and solving duration were negatively correlated, consistent with social learning underlying the spread of solving. Our findings indicate that we can improve our understanding of the diffusion dynamics of innovations in animal groups by investigating group-dependent and individual variables in combination. We introduce novel methods for exploring predictors of the origin and spread of behavioural innovations that could be widely applied.

Abstract: According to scientists human-horse relationship is influenced by management conditions (Hausberger et al.; 2007) including handling methods (Henry et al.; 2005). Furthermore, Henry et al. (2005) show that mares foals" behaviour toward humans may be influenced even by the mares. Although the familiarity of the testperson is said to be an important variable measuring relationship (Waiblinger et al.; 2006), other studies show that horses generalize from the experimenter to unfamiliar humans (Henry et al.; 2005) or from the caretaker to other human beings (Hausberger et al.; 2002).
Methods: 51 horses were observed in a 20x20 sandy arena (familiar to the subjects) to evaluate their relationship with a testperson.
First an arena test was carried out for 5 minutes. The horse was put into the arena alone. After that the person test came in which the testperson interacted with the horse.
The person test consisted of 3 or 4 different phases according to the horse"s behaviour. The phases were: (1.) voluntary animal approach test in which the testperson stood still and the subject was allowed to move wherever it wanted (Appr-vol); (2.) the testperson calling the horse to himself (Appr-call); (3.) the testperson making the horse stay beside him (Stand-still); (4.) the testperson making the horse follow him (without any tools and food reward) (Follow).
First 51 horses were tested with testpersons who were familiar to the animals. After that 39 horses were retested with unfamiliar testpersons within more than one week.
To analyze the potential effects of different human-related factors on the horse behaviour in the person test, such as time spent with training the horse (grooming, riding, working etc.), training methods, number of trainers etc. a questionnare has been used.
Results: Arena test: Horse behaviour was affected neither by their age (2-24 years) nor by their gender (30 geldings and 1 stallion vs 20 mares), however, mares spent more time in the entrance of the arena.
In the test with unfamiliar testpersons (retest) horses stood longer and walked less, which could reflect some habituation to the situation.
Person test: Gender and age of horses or time (years) elapsing since the horse started to be trained did not have any effect on the reactions of horses.
There was a positive correlation between the time (hours) spent with the horse weekly and the time of Follow.
The number of trainers had a significant effect on the Appr-vol and Follow responses: the less the number of the trainers, the sooner the horse approached the familiar testperson and the longer the animal followed him.
In the person test, significant difference was observed only in Appr-vol, thus horses followed the familiar testpersons much longer than the unfamiliar ones. Horses trained to follow their trainers without a lead rope followed significantly longer than animals without this kind of trainings.
Conclusion: Followership seemed to be the most sensitive behavioural response to human familiarity and it may also indicate some other aspects of horse-human relationship, however, training has a clear effect on this human related reaction.