Redefining human-animal relationships: an evaluation of methods to allow their empirical measurement in zoos

Abstract

Scientific studies of human-animal interactions (HAIs) and how these develop into human-animal relationships (HARs) now represent some of the most significant contributions to animal welfare science. However, due to the current definition of HAR, studies have only been able to measure HAIs and infer its impact on HARs and animal welfare. Here, we redefine HARs as a series of repeated HAIs between two individuals known to each other, the nature of which is influenced by their historical HAIs and where consideration to the content, quality and the pattern of the interactions is also vital. With a new definition, it is now feasible to empirically measure HARs, however, first, it is important to evaluate current methods utilised in animal industries to allow standardisation across HAR research in zoos. Here, we review the current methods that have been used to assess HAIs in animals and determine their overall suitability for measuring HARs and their use in a zoo environment. Literature searches were conducted using the search terms 'human-animal' AND 'interaction', 'human-animal' AND 'relationship', 'human-animal' AND 'bond'. Subsequently, 'zoo', 'companion', 'agriculture', 'laboratory' and 'wild' were added to each combination yielding five potential methods to evaluate. These methods were assessed according to a panel of indicators including reliability, robustness, practical application and feasibility for use in a zoo environment. Results indicated that the methods utilising 'latency', 'qualitative behaviour assessment' and the 'voluntary approach test' were potentially viable to assess HARs in a zoo environment and could subsequently contribute to the assessment of welfare implications of these HARs for the animals involved. These methods now require empirical testing and comparisons within a zoo environment.

Using Qualitative Behaviour Assessment to Investigate Human-Animal Relationships in Zoo-Housed Giraffes (Giraffa camelopardalis)

“…Negative keeper actions such as fast sudden movements, speaking loudly and advancing into the flight distance of giraffe, are likely to contribute to the development of negative HAR over time, whereas positive actions such as being calm, fluid movements, speaking softly and providing food, might create more positive HAR. Patel et al [4] outlined that the HAR is a product of repeated interactions between known humans (keepers) and the animal. Therefore, if fast sudden movements are repeated and the giraffe learns that this is not a threat, the giraffe-keeper relationship could remain neutral, as suggested by Hosey’s model of HAR [2].…”

“…Hinde [3] defines an interaction between two individuals as “a sequence in which individual A shows behaviour X to individual B, or A shows X to B and B responds with Y”. Previous studies suggest that repeated interactions between humans and animals in different contexts can lead to the development of a HAR between two individuals known to each other, the nature of which is influenced by their historical HAIs [4]. The content, quality and pattern of the interactions are important aspects to consider regarding measuring HAR, i.e., the human and the animal getting to know each other.…”

“…Within the agricultural literature HAR have been extensively studied, often on the basis of assessing an animals’ levels of avoidance and fear. However, such tests usually require direct contact or approach to elicit a response, which is unsuitable for most zoo-housed species in terms of safety and ethics [4]. In addition, studies of stockperson style on farms have shown these to affect the welfare of farm animals [6,12,13].…”

“…On the other hand, increased time spent by keepers engaging with a range of felid species (including talking to them) correlated with a likelihood of increased reproductive success, suggesting a positive influence [21]. Most studies in the zoo environment focus on specific quantitative aspects of HAI and indirectly reflect on how this may affect HAR, which may be due to lack of suitable methods [4].…”

“…QBA was originally developed for application to farm animal welfare, and has been extensively tested for reliability and biological validity in a range of farm animal species [24,25,26]. QBA was found to be most effective alongside and complementary to traditional quantitative methods, providing information that can help evaluate the meaning of other measures in terms of the animal’s experience and welfare, and it could be used to study HAR in zoos in similar ways [4]. For example, Minero et al [27] applied QBA to measure stabled-horse responses due to human contact, and also measured the horses’ response to additional tests (e.g., human approach tests), conducted independently from the QBA.…”