Sex, Age, and Individual Differences in Bottlenose Dolphins (Tursiops truncatus) in Response to Environmental Enrichment

Abstract

Application of environmental enrichment, as a means to successfully decrease undesired behaviors (e.g., stereotypic) and improve animal welfare, has been documented in a variety of zoological species. However, a dearth of empirical evidence exists concerning age, sex, and individual differences in response to various types of enrichment tools and activities in Atlantic bottlenose dolphins (Tursiops truncatus). This study involved a comparative assessment of enrichment participation of three resident, bottlenose dolphin populations, over the course of 17 months, with respect to sex and age class (calf, sub-adult, adult). Enrichment sessions were randomly assigned, conducted, and categorically assessed based on participation during seven, broad based enrichment classes (Object, Ingestible, Human, or a combination of the three). Overall, the proportion of participation in enrichment sessions was high (≥ 0.74), with individual differences in participation noted among the three populations. Sessions involving Humans and/or Ingestible items resulted in a significantly higher mean proportion of participation. Subadult and adult males were significantly more likely to participate in enrichment sessions, as well as engage in Human Interaction/Object sessions. Calves participated significantly more than adults or sub-adults across all enrichment classes with no noted differences between males and females. These data can serve as a tool to better understand the intricacies of bottlenose dolphin responses to enrichment in an effort to develop strategic enrichment plans with the goal of improving animal well-being and welfare.

Behavioral responses of two species of dolphins to novel video footage: An exploration of sex differences

“…Male bottlenose dolphins watched the television longer and reacted with aggressive and bubble behaviors more than female bottlenose dolphins, while male rough‐toothed dolphins only exhibited significantly more aggressive behaviors than females. This result is similar to previous studies exploring sex differences in male bottlenose dolphins in which males interacted with enrichment devices more often than females (Clark et al, ; Eskelinen et al, ; Kuczaj et al, ). Male bottlenose dolphins have been reported to engage in aggressive interactions in the wild more frequently than females (e.g., Scott, Mann, Watson‐Capps, Sargeant, & Connor, ), thus the increased rate of aggressive behaviors directed toward the video is in line with male behavior in this species.…”

“…Thus, the social housing (2–5 individuals) situation of these cetaceans likely provided additional enrichment, causing the video to be of secondary interest. Previous studies of cetacean enrichment have focused on the number of interactions with objects (Kuczaj et al, ), the mean duration of interactions with specific objects (Delfour & Beyer, ) or the presence of interactions (Eskelinen et al, ) rather than the total percentage of time spent interacting with the enrichment. Thus, exact comparisons between the time dolphins spend watching and interacting with video to other forms of enrichment are currently unavailable.…”

“…Environmental enrichment, the addition of stimuli to animals’ environment, is an essential component of captive animal welfare (Clegg, Borger‐Turner, & Eskelinen, ; Mellen & MacPhee, ). Animal care professionals strategically plan and administer objects, food, caretaker interaction, or other diversified stimuli into the animals’ environment to reduce abnormal patterned behaviors and increase species‐specific behaviors (Eskelinen, Winship, & Borger‐Turner, ; Hoy, Murray, & Tribe, ; Kuczaj, Lacinak, Otto, Trone, & Solangi, ; Mason, ; Newberry, ; Shyne, ). However, husbandry staff must account for evolutionary or ecological constraints that may limit the types of enrichment that will be suitable for particular animals’ social and biological needs.…”

“…Bottlenose dolphins ( Tursiops truncatus ) are reported to display enrichment preferences based on sex (Eskelinen et al, ), with males showing increased interest in enrichment involving human participation and objects compared to females. Male bottlenose dolphins have also been documented to interact with cognitively challenging enrichment more frequently than females (e.g., Clark, Davies, Madigan, Warner, & Kuczaj, ; Kuczaj, Winship, & Eskelinen, ).…”

Environmental changes and anthropogenic factors modulate social play in captive bottlenose dolphins (Tursiops truncatus)

“…Toys are often used to improve the animals’ welfare by increasing the complexity of the dolphins’ environment and to give them the opportunity to engage in play behavior with the provided objects (Kuczaj et al, ). In some cases, human presence seems to be more enriching for bottlenose dolphins than objects (Eskelinen, Winship, & Borger‐Turner, ), and dolphins exhibit an increase in play behaviors following dolphin–human interaction programs (Trone, Kuczaj, & Solangi, ). However, there is a lack of studies on the impact of anthropogenic elements of captive environments (e.g., noise) which might affect the dolphins’ social behavior (Bauer, Mobley, & Herman, ).…”