Effects of a modern exhibit design on captive tiger welfare.

Offering captive animals larger, more complex spaces are thought to benefit their welfare. To this end, some zoos use trail systems linked to several enclosures. Since little is known about the effects of such designs on the welfare of captive carnivores specifically, we timed the behaviors exhibited by four tigers (Panthera tigris [Linnaeus]) given access to three exhibit configurations: one exhibit only (E, baseline); one exhibit and approximately 19 m2 of trail (ET); and two exhibits connected by approximately 46 m2 of trail (E2T). Behaviors were recorded during 1-h AM, Noon, and PM periods in Phase I (2017), and 2-h AM and PM periods in Phase II (2018). Percentages of behavior occurrence were analyzed using generalized linear mixed models (GLMM), with treatment and time of day as fixed effects. Tigers were least active at noon (Phase I), while active behaviors were prevalent during mornings and afternoons in both Phases. In Phase II (E2T vs. E), active and exploratory behaviors such as sniffing increased, while pacing and inactivity decreased (all p ≤ .001). We also examined nocturnal tiger movement using infrared motion-activated cameras. In parallel with diurnal observations, tiger activity in E2T greatly exceeded that in E. Nocturnal movement was most pronounced from 1800 to 2200 and least frequent from 0100 to 0400, closely matching patterns observed in the wild. Results indicate that offering tigers voluntary access to larger and more complex spaces stimulates natural behaviors and decreases stereotypical behaviors.

Effects of guest feeding programs on captive giraffe behavior.

Zoological institutions develop human-animal interaction opportunities for visitors to advance missions of conservation, education, and recreation; however, the animal welfare implications largely have yet to be evaluated. This behavioral study was the first to quantify impacts of guest feeding programs on captive giraffe behavior and welfare, by documenting giraffe time budgets that included both normal and stereotypic behaviors. Thirty giraffes from nine zoos (six zoos with varying guest feeding programs and three without) were observed using both instantaneous scan sampling and continuous behavioral sampling techniques. All data were collected during summer 2012 and analyzed using linear mixed models. The degree of individual giraffe participation in guest feeding programs was positively associated with increased time spent idle and marginally associated with reduced time spent ruminating. Time spent participating in guest feeding programs had no effect on performance of stereotypic behaviors. When time spent eating routine diets was combined with time spent participating in guest feeding programs, individuals that spent more time engaged in total feeding behaviors tended to perform less oral stereotypic behavior such as object-licking and tongue-rolling. By extending foraging time and complexity, guest feeding programs have the potential to act as environmental enrichment and alleviate unfulfilled foraging motivations that may underlie oral stereotypic behaviors observed in many captive giraffes. However, management strategies may need to be adjusted to mitigate idleness and other program consequences. Further studies, especially pre-and-post-program implementation comparisons, are needed to better understand the influence of human-animal interactions on zoo animal behavior and welfare.

Ubiquitous variability in the prevalence of Trichobilharzia stagnicolae (Schistosomatidae) infecting Stagnicola emarginata in three northern Michigan lakes.

During 4 consecutive collecting seasons from 1998 through 2001, 77,326 common beach snails (Stagnicola emarginata, Lymnaeidae) were examined for infections by Trichobilharzia stagnicolae from multiple sites on Walloon Lake, Higgins Lake, and Lake Leelanau, located in the northern region of the lower peninsula of Michigan. Snails were examined for infections using the light-box technique (exposure to bright fluorescent light). The prevalence of infected snails varied significantly among lakes within a year, between years in a lake, at a site from year to year, and at a site over a collecting season. Overall annual prevalence ranged from 0.54% (1999) to 1.32% (2001) on Walloon Lake, from 0.56% (2001) to 1.06% (1998) on Higgins Lake, and 0.30% (2001) to 0.89% (2000) on Lake Leelanau. Generally, the peak in prevalence coincided in July on the lakes. Prevalence was found to increase with snail length in all lakes. A comparison of the light-box technique and crushing snails demonstrated that prevalence varied in magnitude by technique as much as 1.2 and 5.7 times.