Activity and Pool Use in Relation to Temperature and Water Changes in Zoo Hippopotamuses (Hippopotamus amphibious)

Abstract

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.

Island Life: Use of Activity Budgets and Visibility to Evaluate a Multi-Species Within-Zoo Exhibit Move

“…Activity budget comparison during a management or environmental change is often used to assess whether an intervention has influenced animal behaviour [ 3 , 23 , 26 , 46 ]. Here, we presented activity budgets for four species during three periods of data collection: pre-move, early-post and where available, post-move.…”

“…Thus, the documentation of these behaviours forms an essential component of any welfare monitoring process. Accurate evaluation of behaviour post-exhibit move using robust and consistent methodology will enable the application of an evidence-based approach to species management and exhibit design [ 23 , 24 , 25 ]. Additionally, because behavioural changes in response to enclosure moves may not be immediately apparent [ 26 ] or may be an initial response to a novel situation [ 27 , 28 ], it is important to account for a habituation period to management or environment modifications.…”

A Systematic Review of the Use of Technology to Monitor Welfare in Zoo Animals: Is There Space for Improvement?

“…Similarly, using sensor technology such as microphones and data-loggers to continuously measure environmental parameters can provide extra information on how they may influence animal welfare. A better understanding of animals by integrating both approaches, as seen in studies on hippos [ 48 ] and giant anteaters [ 40 ], can ultimately be useful for management decisions. The use of wearable sensors such as GPS collars and RFID tags was also found promising by the authors in determining social relationships in elephants [ 41 ] and behavioural swimming patterns in penguins [ 45 ] by overcoming possible disadvantages of traditional methods like the observer fatigue, visual obstruction, and lack of identifying certain behaviours.…”

Freedom and Animal Welfare

“…The territory size for wild animals does not necessarily represent the amount of roaming they desire but can just be the amount of space needed to contain all the required resources for survival-sufficient sources of food, water and shelter [45]. A captive environment that provides all these needs within a smaller space may then be entirely sufficient-this will depend on details about the specific biology and behaviour of the animals of interest [46,47]. For example, some wide-ranging carnivores demonstrate stereotypes in captivity despite having their other needs provided, which suggests that for them, space itself is relevant [48].…”

“…As well as comparing ecology and behaviour, comparative welfare data could help form part of this analysis. There are also many research projects that look to compare the housing and husbandry conditions and behavioural and activity patterns between captive and wild species to try and identify welfare-relevant differences [46,47,80]. Veasey [77] provides an example of how an empirical analysis of the evolutionarily important cognitive and behavioural processes for a species can help determine their likely welfare in a captive setting and set priorities for improvement.…”