Search Behavior in Various Breeds of Adult Dogs (Canis familiaris): Object Permanence and Olfactory Cues

Human analog tests of object permanence were administered to various breeds of adult dogs (Canis familiaris). Experiment 1 showed that the performance of terriers, sporting, and working dogs did not differ. Dogs succeeded in solving invisible displacement problems, but performance was lower than in visible displacement tests. Familiarity with the task had some influence because […]

Object permanence tests on gibbons (Hylobatidae)

Ten gibbons of various species (Symphalangus syndactylus, Hylobates lar, Nomascus gabriellae, and Nomascus leucogenys) were tested on object permanence tasks. Three identical wooden boxes, presented in a linear line, were used to hide pieces of food. The authors conducted single visible, single invisible, double invisible, and control displacements, in both random and nonrandom order. During […]

Object permanence in orangutans, gorillas, and black-and-white ruffed lemurs

This study examined object permanence in Sumatran orangutans (Pongo abelii), Western lowland gorillas (Gorilla gorilla gorilla), and black-and-white-ruffed lemurs (Varecia variegata) at Zoo Atlanta. A literature review reveals two main issues with object permanence research in non-human primates. One of the issues is that it is difficult to make valid comparisons between different species because […]

Can Black-and-White Ruffed Lemurs (Varecia variegata) Solve Object Permanence Tasks?

We examined object permanence in black-and-white-ruffed lemurs (Varecia variegata) at Zoo Atlanta. A series of visible and invisible displacement tasks with suitable controls were presented to five adult subjects. Subjects performed significantly above chance on all regular tasks, except for the double invisible displacements. Subjects failed visible and invisible controls. Failure on the control trials […]

Object permanence in domestic dogs (Canis lupus familiaris) and gray wolves (Canis lupus)

Recent evidence suggests that phylogenetic constraints exerted on dogs by the process of domestication have altered the ability of dogs to represent the physical world and the displacement of objects. In this study, invisible (Experiment 1) and visible (Experiment 2) displacement problems were administered to determine whether domestic dogs’ and gray wolves’ cognitive capacities to […]