Abstract: The Minnesota Zoological Garden established a bachelor (i.e. all-male) group of 8 Przewalski horses (Equus przewalskii) in 1984. Possible methods for mixing males emerged through preliminary introductions and review of the relevant literature. These included: (1) grouping colts (<=3 years old) after removing them from their natal bands; (2) introducing adult stallions to colts in spacious, controlled environments to reduce the risk of combat-related injury or death associated with largely unpredictable adult temperament; (3) introducing more than 1 animal at a time to established groups. Based on the frequency and orientation of agonistic interactions observed among the bachelors, a linear dominance hierarchy was discerned among the 4 adult stallions; all 4 colts were determined to be of equally low or seemingly non-ranking status. Social rank among the adults was most influenced by individual temperament, and contention for rank was limited almost exclusively to the 3 lower-ranking stallions; the alpha male participated in 73% of all agonistic interactions observed, but was identified as the recipient in less than 3% of these interactions. Intra-band associations were detected in the bachelor group. The most prevalent of these was among the 4 colts, found together in over 70% of the observations. Other affinities commonly observed were between the colts (as a sub-group) and different stallions. The dominant stallion, the colts' most frequent companion, actively discouraged the 3 lower-ranking stallions from associating with the colts. Further, the colts were subjected to significantly fewer agonistic behaviors than the non-alpha stallions (per colt=1.05+/-0.24 h-1; per non-alpha stallion=2.01+/-0.04 h-1). These findings support the hypothesis developed by other workers for ungulates that young bachelors are sheltered from aggression by association with an alpha male. With one exception, adult associations were rarely noted. Although combat-related injuries (superficial wounds and temporary lameness) were common among the bachelors, few required medical attention. No permanent disabilities or deaths have occurred since the group's inception. The existence of social organization and intra-band associations in the bachelor group support the suggestion that such groups were once a natural part of this species' social milieu. Bachelor groups are therefore recommended as an ethologically sound, space- and cost-effective means of managing “surplus” (i.e. non-harem) male Przewalski horses.

Abstract: This experiment examines the cues used by cattle to discriminate between people, particularly the role played by facial cues. We trained and tested eight Holstein cows 5 days each week for 2 months. For each cow, we used two people, a rewarder and a non-rewarder, of different size and dressed in overalls of the same colour. The operant chamber was a large box within which stood the two people. The cow could see, smell and touch each person. A lever was placed in front of each person. When the cow pushed the lever in front of the rewarder, it received 75 g of concentrate and nothing when it pushed on the other one. For each test session, the cows made 10 choices. The placement of the people was determined randomly according to the Gellerman series. The success criterion was defined as at least eight correct choices out of 10 trials for two consecutive sessions (binomial law P<0.003). During the shaping, seven cows out of eight learned to press the lever to obtain the food. The cows were then tested in a series of 10 trials with only the rewarder present. Seven out of seven cows succeeded in reaching the success criterion. In experiment 1, both the rewarder and the non-rewarder were present and standing upright at normal height and in full view of the cow. Five out of seven cows achieved the success criterion. In experiment 2, the cows could see only the faces of the two people. None of the cows were able to reach the success criterion. In experiment 3, both people were present standing up and wearing identical masks that completely covered their heads. Five cows out of five achieved the success criterion. In experiment 4, we changed the relative height of the people. Five cows out of five succeeded when the two people stood so they were of equal height but with their faces visible. However, no cows succeeded when the people were both of equal height and had their faces covered. This study suggests that cows seem to use multiple cues to discriminate between people. Cows appear able to use either body height or the face to discriminate between people but use of the face alone is more difficult when the cows cannot see the rest of the body.

Abstract: Epinephrine and norepinephrine plasma levels were assessed in dogs in relation to paw preference following an immune challenge with rabies vaccine. The results showed that both catecholamines increased after the vaccine administration, confirming the main role of the sympathetic nervous system in the modulation activity between the brain and the immune system. Moreover, ambidextrous dogs showed a significantly higher increase of epinephrine levels 8 days after immunization with respect to right- and left-pawed dogs, suggesting that the biological activity of this molecule could be key for a different immune response with regard to laterality.

Abstract: The objective of the study was to analyze certain factors influencing the condition of free-ranging Konik Polski horses in a fenced area measuring 200 ha located in the Biebrza National Park (Biebrza NP). The Body Condition Scoring system (BCS) was used not only as means of assessment of health and fitness of the horses but also for evaluation of the quality and productivity of the grazing area selected for horses, as well as stocking rate. Body Condition Scoring was determine with a 9-point scale by averaging the scores that were assigned to each of the six body areas that are most responsive to changes of body fat (Hennecke, 1983). The condition of horses was assessed 7 times from February 2009 to December 2011 on a total of 59 horses (3 stallions (n= 12 observations), 21 females 3–8 year olds (n=81) and 35 youngsters (up to 2 year olds) (n=88). The number (from 1 to 3) and composition of family bands varied throughout the period of investigation. The horse population in the Biebrza NP consist of horses from 3 different breeding centers. The analysis of variance (GLM) was used to investigate the effects of the fixed factors – weather conditions, family band, breeder of the horses, age and sex, on the mean of BCS points of horses (SPSS, version 19.0). The most important factor influencing the condition of free-ranging Konik Polski horses in the Biebrza NP were weather conditions, what is shown by the data concerning temperature from 3-month period preceding condition scoring (P < 0.01). This factor influenced not only animals, but also vegetation characteristics. The highest BCS means of horses (5.09) were achieved when average temperature during the 3-month period preceding condition scoring amounted between +1 to +8°C, and was better than obtained when average temperature amounted +18°C (4.80). The last temperature seems too high for horses and can be connected also with other factors, like high incidence of insects which could deteriorate grazing activity of animals. The lowest BCS means (4.56) were obtained when mean temperature was below 0°C. Other factors had no significant effect on the BCS means. As concern to breeder, the highest BCS means achieved mares from Popielno (5.08) – the oldest Polish free-ranging population of Konik Polski horses, which confirms that horses from this breeding center are justly considered to be the toughest and well adapting to difficult environmental conditions. The horses from the Biebrza NP achieved also high BCS means (4.79) which prove that they were well suited to the specific conditions of this habitat, which is overgrown mostly with forest – 73,7%, and willow and birch shrubs – 13,3% of area. The grazing area measures about 40 hectares and consists of wetlands dominated by sedges (Carex sp.). The horses moved from the Seven Island Reservation to Biebrza NP achieved the poorest results as far as adaptation to the conditions of the new habitat, and reached the lowest BCS means (4.57). The youngest horses (up to 2 year olds), 3-5 year olds, and 6-8 year olds had similar BCS means (respectively 4.94, 4.83, 4.68) which indicates good acclimatization of horses from different age categories to the grazing resources in the Biebrza NP. The highest means achieved by youngest horses indicate important trait of Konik Polski horses – mare`s careful care of offspring. The BCS means of horses from different family groups show the highest value of horses from family group of the most experienced stallion – Mrok (4.97). In every BCS scoring, stallions achieved the highest means, which was the reason to exclude their results from analysis. The results of this study suggest that the Body Condition Scoring of horses in the Biebrza National Park depends primarily on the acclimatization of horses to harsh environmental conditions and less importantly to belonging to a specific breeder, family band, age or sex.