Penguins are considered among the most popular animals for zoo and aquarium visitors to observe. Swimming is considered a desirable activity, both for the visitor experience and the welfare of the penguins. However, little is known about the amount of time exhibited penguins spend swimming, or how such swimming is related to regular feeding events. We examined the effects of introducing live prey in the form of trout on 22 Humboldt penguins living at the Woodland Park Zoo. Of primary interest was how the live feeds changed (1) daily and hourly swimming activity, and (2) variability in enclosure use. We hypothesized that the live feedings would increase swimming activity prior to and during the delivery of the live trout, as well as create an overall increase in total swimming activity for live feed days compared to non-live feed days. We also predicted that the penguins would be more likely to use the entire exhibit around these live feeds, since they are likely to chase fish throughout the exhibit. Penguins did show an increase in swimming activity in the hour prior to and during the live feed, with a small decrease in swimming activity following the live feed when compared to non-live feed days. There was also a more than 30% increase in the total swimming activity for live feed days when compared to all other non-live feed days. In addition, a single measure of variability in enclosure use (entropy) showed greater overall enclosure use for the live feed days compared to the non-live feed days. These results demonstrate that live fish can be a useful way of enriching the behavioural welfare of Humboldt penguins.

The past two decades have seen increased interest in studies examining the welfare of elephants and animal–visitor interactions. One understudied area for both pursuits is the impact of public feeding interactions. Our study examined the effects of public feedings on the general activity of three zoo-housed elephants. Prior to public feedings, we developed and assessed a 21-behavior ethogram split into six classes of behavior. Comparisons between the elephants demonstrated that only one of the elephants engaged in stereotypies with regularity (>30%), and that the stereotypies occurred in place of most foraging. During public feedings, we compared the general activity of each elephant independently and across both public feeding and nonpublic feeding days, as well as the general activity before, during, and after a public feeding. Public feedings increased social activity and decreased stereotypies when compared with nonpublic feeding days for two of the elephants. In addition, all three elephants showed increased foraging and decreased inactivity in the period after a public feeding session. These results demonstrate that public feedings can be a useful tool for enriching the welfare of zoo-housed elephants and are among the first sets of data to demonstrate positive welfare outcomes associated with public feedings.

In the wild, hippopotamuses spend much of their daily activity in the water. In zoos, it is less clear the extent to which hippos spend time in the water. We examined how much time Woodland Park Zoo’s three hippos spent in their outdoor pool, based on: (a) temperature of the pool water, and (b) when the pool water was changed (approximately three times a week). Several digital temperature data loggers collected water and air temperature readings once every hour for six months. We correlated the water temperature readings with several behaviors the hippos could engage in, where the hippos were on exhibit (pool vs. land), and how many days it had been since a dump (0, 1, or 2 days). The results indicated that water changes had little effect on pool usage, while increasing water temperatures resulted in both increased activity and pool use. The results are discussed in terms of how these findings relate to wild hippo activity, current knowledge of zoo-housed hippo welfare, and future directions for zoo-housed hippo welfare and research.