Don’t Demean “Invasives”: Conservation and Wrongful Species Discrimination

It is common for conservationists to refer to non-native species that have undesirable impacts on humans as “invasive”. We argue that the classification of any species as “invasive” constitutes wrongful discrimination. Moreover, we argue that its being wrong to categorize a species as invasive is perfectly compatible with it being morally permissible to kill animals—assuming […]

Asian elephants (Elephas maximus) discriminate between familiar and unfamiliar human visual and olfactory cues

Social animals use individual identity cues to form and maintain social relationships with conspecifics. This ability to discriminate between individuals extends to heterospecifics in some social mammals. The aim of this study was to determine if Asian elephants (Elephas maximus) could differentiate between familiar and unfamiliar people using visual, auditory, and olfactory cues independently. Two […]

Odorant discrimination by tiger salamanders after combined olfactory and vomeronasal nerve cuts

Tiger salamanders (Ambystoma tigrinum) were trained to respond to n-butyl acetate, 8.9×10-5 M; 2.7×10-6 M. Then they were given combined bilateral olfactory and vomeronasal nerve cuts (NC) or sham surgery (S). After surgery, animals were tested at two concentration levels for responding to butyl acetate and discriminative responding between butyl acetate and butyl alcohol. NC […]

Color vision in horses- Deficiencies identified using Pseudoisochromatic plate test

In the past, equine color vision was tested with stimuli composed either of painted cards or photographic slides or through physiological testing using electroretinogram flicker photometry. Some studies produced similar results, but others did not, demonstrating that there was not yet a definitive answer regarding color vision in horses( Equus caballus). In this study, a […]

Discrimination generalization by macaque monkeys to unidimensional and multidimensional stimul

The purpose of this investigation was to study the factors influencing the generalization of stimuli in macaque monkeys. Twelve animals were used. The stimuli to be discriminated differed in size, form, and color. Generalization was demonstrated for most of the test. The monkeys generalized in terms of avoidance to the negative stimulus to as great […]

Cognitive experience and its effect on age-dependent cognitive decline in beagle dogs

Test-sophisticated beagle dogs show marked age sensitivity in a size discrimination learning task, with old and senior dogs performing significantly more poorly than young dogs. By contrast, age differences in learning were not seen in dogs naïve with respect to neuropsychological test experience. These results indicate that old animals benefit less from prior cognitive experience […]

Visual categorization of natural stimuli by domestic dogs

One of the fundamental issues in the study of animal cognition concerns categorization. Although domestic dogs (Canis familiaris) are on the brink to become one of the model animals in animal psychology, their categorization abilities are unknown. This is probably largely due to the absence of an adequate method for testing dogs’ ability to discriminate […]

Differences in between-reinforcer value modulate the selective-value effect in great apes (Pan troglodytes, P. Paniscus, Gorilla gorilla, Pongo abelii)

We investigated how apes allocated their choices between 2 food options that varied in terms of their quantity and quality. Experiment 1 tested whether subjects preferred an AB option over an A option, where the A item is preferred to the B item (e.g., apple + carrot vs. apple). Additionally, we tested whether the length […]

A new method of walking rehabilitation using cognitive tasks in an adult chimpanzee (Pan troglodytes) with a disability: a case study

There are few studies of long-term care and rehabilitation of animals which acquired physical disabilities in captivity, despite their importance for welfare. An adult male chimpanzee named Reo at the Primate Research Institute of Kyoto University, developed acute myelitis, inflammation of the spinal cord, which resulted in impaired leg function. This report describes a walking […]