This study presents a first-step examination of the auditory reception of Reeves’s muntjac in response to pure tone stimuli. Nine experimental animals were tested with restricted visual interactions. The animals were exposed to nine pure tones, ranging from 50 Hz to 40 kHz, presented in ascending order of frequency. Each sound was presented for 10 s, followed by a 30-s silent interval. Over 60% of the muntjacs responded to all sounds by moving and localizing their ears, indicating that frequencies ranging from 50 Hz to 40 kHz are within their audible range. Two animals exhibited body jerks due to momentary muscle contractions at 30 kHz, while one animal each responded with avoidance behavior at 50 Hz, 5 kHz, and 30 kHz. No significant differences in sound duration were found across frequencies; however, individual variation was significant (P<0.001). Based on these results, the auditory reception of Reeves’ muntjac is estimated to range from 50 Hz to 40 kHz. Certain frequency tones may also transiently influence their behavior. However, relying solely on the sounds tested in this study-which induce startle or escape responses-is insufficient for long-term behavioral control.

This study investigated the effects of barn relocation on behavior and fecal corticosterone concentrations in giraffes. Between July 2021 and August 2023, four giraffes from Saitama Children’s Zoo, Japan, were sampled pre-relocation (for 15 days), immediately post-relocation (for 7 days), 5-6 months post-relocation (for 15 days), and 17-18 months post-relocation (for 15 days) using a 5-min interval instantaneous scan sampling technique. In addition, feces were collected every 2 days during each period, and fecal corticosterone concentrations were measured. Both locomotion and fecal corticosterone concentrations increased significantly immediately post-relocation and remained elevated at 5-6 months post-relocation. However, at 17-18 months post-relocation, locomotion returned to pre-relocation levels, and fecal corticosterone concentrations significantly decreased. These findings suggest that the effects of barn relocation on giraffes persist for at least 5-6 months.

Currently, carcass feeding has been used in Japanese zoos; however, its effects on animal behavior and educational effects on visitors remain unclear. This document focuses on carcass feeding using chickens conducted at Kyoto City Zoo. It investigates the effects on visitors’ awareness of the animal welfare of egg-laying hens and their behavior toward one jaguar. Educational effectiveness was evaluated using text mining of free-text statements from 195 questionnaires completed by participants in a jaguar carcass feeding program conducted from October to November 2021. Behavioral evaluations were performed on one jaguar between February and May 2024. The results showed that the free-text descriptions included statements about stimulating awareness of the hen housing environment and reducing food losses. The jaguar’s behavior was similar to that reported in previous studies, with a significant decrease in pacing behavior and a significant increase in foraging behavior during chicken carcass feeding. In other words, by feeding chicken carcasses, it was possible to contribute to the awareness of zoo visitors about the welfare of laying hens and improve the foraging environment of carnivores, as shown in previous studies.