A Brief Glimpse at the Long Evolutionary History of Play

Play has long been considered an enigmatic behavior that is hard to define, but having many putative functions difficult to confirm. This situation is changing quite rapidly in recent years. This introduction to a special issue on play provides some general background, historical and contemporary, on the recognition and phylogenetic aspects of play, along with […]

Play in Rats: Association across Contexts and Types, and Analysis of Structure

Play has been proposed as a promising indicator of positive animal welfare. We aimed to study play in rats across contexts (conspecific/heterospecific) and types (social: pinning, being pinned; solitary: scampering), and we investigated its structure using behavioral sequence analysis. Group-housed (three per cage) adolescent male Lister Hooded rats (n = 21) were subjected to a […]

Play Behavior in Crocodilians

Play behavior in crocodilians is not uncommon, but it remains virtually undescribed in scientific literature. I present the first overview of play behavior of three types (locomotor play, object play and social play) in crocodilians based on original observations, published reports and anecdotal evidence. Object play is the type most often reported; social play can […]

Young Belugas Diversify Adult Beluga (Delphinapterus leucas) Behavior

Across the animal kingdom, immature animals are characterized by their playfulness and diversity of behavior, but are their actions enriching to adult conspecifics? The purpose of this study was to assess if beluga (Delphinapterus leucas) calves influenced the behavioral repertoire of adult conspecifics, specifically with regard to play behaviors, social interactions, and solitary swimming. Video […]

Short-term benefits of play behavior and conflict prevention in Pan paniscus

Most theories on the function of play have focused on ultimate rather than proximate benefits. Play peaks during juvenility but, in some species, it is present in adulthood as well. In primates, social play and grooming often show a matched pattern because they bring individuals into close contact and favor social cohesion. In Pan, researchers […]

Assessment of positive emotions in animals to improve their welfare

It is now widely accepted that good welfare is not simply the absence of negative experiences, but rather is primarily the presence of positive experiences such as pleasure. However scientific investigation of positive emotions has long been neglected. This paper addresses two main issues: first, it reviews the current state of scientific knowledge that supports […]

The neurobiology of positive emotions

Compared to the study of negative emotions such as fear, the neurobiology of positive emotional processes and the associated positive affect (PA) states has only recently received scientific attention. Biological theories conceptualize PA as being related to (i) signals indicating that bodies are returning to equilibrium among those studying homeostasis, (ii) utility estimation among those […]

Cage Design and Forms of Play in Red-Bellied Tamarins, Saguinus labiatus

Abstract 10.1002/zoo.1430110310.abs We investigated the role of cage design in the expression of play in a group of red-bellied tamarins (Saguinus labiatus). For each of the four play behaviors that were measured in this study (wrestle, pounce, grasp, and chase), significant differences in frequency appeared as a function of substrate. When playing on broad, flat, […]

Functions and social consequences of infant–adult male interaction in a captive group of lowland gorillas (Gorilla gorilla gorilla)

Abstract 10.1002/zoo.1430080204.abs The functions and social consequences of infant-adult male interaction in a captive group of lowland gorillas were evaluated. The two males repeatedly attempted to interact with the infant, the infant sometimes attempted to interact with the males, and the mother usually interrupted interactions between male and infant. Infant-directed actions by the two males […]

Effects of environmental enrichment on males of a docile inbred strain of mice

Environmental enrichment is intended to improve the welfare of laboratory animals. However, regarding male mice, numerous studies indicate an increase in aggressive behavior due to cage structuring. On the one hand, this might be a problem concerning animal welfare. On the other hand, enrichment is though to hamper environmental standardization and to increase variability of […]