In this study, the influence of the differences in the amount of food and positioning food on a pattern of eating behavior of Japanese wild boars (Sus scrofa leucomystax) was investigated. We built a circular experimental arena with eight partitioned feeding sites. Six out of eight sites are in a semicircle. Five wild boars were trained and familiarized to eat food in all divided sites. In the experiment, completely trained individuals were allowed to eat freely at two sites on the left and right ends in a semicircle. Mini cookies about 1cm in diameter were used as food. Four different combinations were setup for the differences, and the split ratios were 50 to 10 cookies, 40 to 20 cookies, 35 to 25 cookies, and 30 to 30 cookies at two sites. In Experiment 1, mini cookies were placed in a horizontal row, and were aligned in columns and rows on a grid in Experiment 2. Each experiment had eight sessions in total (4 combinations × 2 sessions), and one session consisted of five trials. Each of combinations was placed twice in the first and second session. For the second session, the sites were switched. In Experiment 1, wild boars showed a tendency to move to the right side or eat at the site on the right (R site), regardless of the number of cookies. In Experiment 2, they did not show a tendency to move and eat at R site, and showed a tendency to choose a larger amount of food when the combination was 50 to10 cookies. From these results, it is clear that wild boars preferentially eat a larger amount of food when the difference is obviously big, but they eat regardless of the amount of food when the difference is small or not obvious. It suggests that wild boars could recognize the difference in the amount of food more clearly depending on positioning food.

The aim of the study was development of an alternative housing system that is easy to duplicate. We constructed a furnished cage using 6 conventional cages. Two nest areas were provided both ends of the cage and were combined with a dust bath. Fifty-six White Leghorn (Julia) hens aged 123 days were allocated to 8 furnished cages. All aggressive behaviors were directly observed to calculate a dominance ranking. Behaviors and use of the resources were recorded using a direct visual scan sampling technique at 10 min intervals. Locations where eggs were laid and the behaviors and locations of the highest and lowest rank hens were recorded. In the modified cages in this study, the hens habituated the environment in a few days after the introduction to the cage. The rate of aggressive behavior was low, no severe feather pecking was observed, and a wide variety of behaviors were observed. The combined nest and dust bath was used not only for laying eggs and sham dust bathing but also for refuge by the low ranked hens. Therefore, separation of resources and combined nest and dust bath are functional in this cage design and group size.

We investigated the ability of two sika deer (Cervus nippon nippon) to discriminate between three primary colors (red, green, and blue) and gray under light and dark conditions (Experiment 1 and Experiment 2) using a T-maze technique. The light intensity in the center of a stimulus color card in Experiment 1 was 200lux and that in the Experiment 2 was 0.1lux. One session consisted of 20 trials. The criterion of successful color discrimination was 16 or more correct choices out of 20 trials for 3 sessions in a row (P < 0.01 by Chi-square test). Experiment 1: Both sika deer fulfilled the criterion in the 4th, 3rd, and 3rd sessions in the discrimination test between green and gray, red and gray, and blue and gray. Experiment 2: In each of the green vs. gray and blue vs. gray discrimination tests, two sika deer fulfilled the criterion by the 3rd session. The correct responses of two sika deer fulfilled the criterion within the 6th session in the discrimination test between red and gray. In conclusion, sika deer did have a high ability for discrimination between the three primary colors (red, green, and blue) and gray under light-dark conditions, thereby valuable information for the development of effective methods for preventing deer invasion was obtained.