Assessing the effectiveness of environmental enrichment in bottlenose dolphins (Tursiops truncatus)

Abstract

Environmental enrichment is often used to improve well-being and reduce stereotyped behaviors in animals under human care. However, the use of objects to enrich animal environments should not be considered to be effective until its success has been scientifically demonstrated. This study was conducted at Asterix Park in France in April 2009. The study investigated the use of 21 familiar objects with a group of six bottlenose dolphins (Tursiops truncatus). The dolphin trainers introduced four different objects into the dolphin pool every day on a rotating basis. Using a focal-object sampling method, we collected and analyzed data from twenty-one 15 min sessions. The results revealed a positive correlation between interest behaviors and interactive behaviors. Some dolphins had "favorite toys". However, only 50% of objects elicited manipulative behaviors. These findings demonstrate that dolphins do not treat all objects provided to them as "toys". Behavioral changes in the animals subsequent to the introduction of objects do not necessarily indicate an enrichment effect of the objects; rather, the motivation for the dolphins' behaviors toward the objects must be investigated. The animals' behavior must be considered in light of the social context and of the animals' individual behavioral profiles. The relevance of a constructivist approach to evaluating the effectiveness of enrichment programs is discussed.

Body Contacts and Social Interactions in Captive Odontocetes Are Influenced by the Context: An Implication for Welfare Assessment

“…For BDs, the presence of humans together with toys was associated with a lower rate of agonistic behaviors between animals, which is an interesting result to further investigate. It has already been shown that BDs are likely to interact with caretakers outside of training sessions and interact with toys more frequently when caretakers are involved [79,80]; combining these two kinds of enrichment might therefore increase their enriching properties. EAFPs engaged in socio-sexual interactions more often when toys were provided.…”

“…When aiming to give more opportunities of control to captive animals, the needs of a given species and even of each individual must be considered when utilizing different types of enrichment, social groupings, or habitat configurations [91][92][93]. Differences of reaction to each type of enrichment among the three groups we studied might therefore reflect preferences for certain type of enrichment [79,80], and also the way they interact with each type of enrichment (alone, together, with or without distance between individuals). The differences we found between groups could be linked with species-specific traits, such as shyness for YFPs, and individual differences might play a role in the reaction to enrichment [79].…”

“…Differences of reaction to each type of enrichment among the three groups we studied might therefore reflect preferences for certain type of enrichment [79,80], and also the way they interact with each type of enrichment (alone, together, with or without distance between individuals). The differences we found between groups could be linked with species-specific traits, such as shyness for YFPs, and individual differences might play a role in the reaction to enrichment [79]. In addition, the animals' management and especially the training routine and the relationship with caretakers might have been a factor that influenced the preference for a certain type of enrichment and even explain the preference for interacting with caretakers rather than socializing with conspecifics.…”

Cognitive Bias in Zoo Animals: An Optimistic Outlook for Welfare Assessment

“…For example, for a species that is generally human-shy in captivity and where the group is managed extensively, a pertinent question might be whether they show increased negative biases during days/periods when keepers or maintenance staff enter the enclosure. Individual differences such as personality and social hierarchy should be taken into account when imposing experimental manipulations to alter welfare state: if the effect of enrichment was being tested, experimenters should be aware that individuals with different personalities might perceive the resource in different ways, and that access to the enrichment itself might be dictated by position in the social hierarchy [ 15 , 112 , 113 ].…”

An Inventory of Peer-reviewed Articles on Killer Whales (Orcinus orca) with a Comparison to Bottlenose Dolphins (Tursiops truncatus)

“…Leger et al, 2009;physiology: Worthy, Worthy, Yochem, & Dold, 2013;reproduction, Asper, Young, & Walsh, 1988;Robeck et al, 2009). Even research on aspects of cognition and sociality of bottlenose dolphins has been conducted in both wild and captive settings and resulted in information that facilitated more species-appropriate forms of enrichment and social groupings for captive animals (Fabienne & Helen, 2012;Waples & Gales, 2002). Research with killer whales may benefit from similar studies.…”