Beef calves react differently to different handlers according to the test situation and their previous interactions with their caretaker

Since birth, twenty-four beef calves received either minimal or extensive contact with one experimenter and were observed in three tests between three and four months of age. In the first test, the calves observed with the familiar motionless experimenter spent less time away from a feeding bucket (5.6 ± 4.0 s) than when with an […]

Welfare of Apes in Captive Environments: Comments On, and By, a Specific Group of Apes

Accurately determining the proper captive environment for apes requires adequately assessing the psychological similarities between apes and humans. Scientists currently believe apes lack mental complexity (Millikan, 2006), raising questions concerning the evolution of human culture from ape-like societies (Tomasello, 1999) .A long-term cultural study with bonobos suggests less intellectual divergence from humans than currently postulated […]

Perception of real-world without a language

The aim of this study is to show how real-world knowledge works without language. Lelio is a 76-year-old man who has been profoundly deaf since birth like his mother and brothers. In the clinical history, Lelio’s father was reported as affected by an unspecified “cerebropathy”. Lelio’s two brothers had a relatively normal life. Lelio is […]

What is it like to be a rat? Rat sensory perception and its implications for experimental design and rat welfare

This review of rat sensory perception spans eight decades of work conducted across diverse research fields. It covers rat vision, audition, olfaction, gustation, and somatosensation, and describes how rat perception differs from and coincides with ours. As Nagel’s seminal work (1974) implies, we cannot truly know what it is like to be a rat, but […]

The implications of cognitive processes for animal welfare

In general, codes that have been designed to safeguard the welfare of animals emphasize the importance of providing an environment that will ensure good health and a normal physiological and physical state, that is, they emphasize the animals’ physical needs. If mental needs are mentioned, they are always relegated to secondary importance. The argument is […]

Vigilance during food handling in grey squirrels, Sciurus carolinensis

Foraging and vigilance conflict in animals that lower their head during food search and handling, but it is less clear whether these activities conflict in animals that handle food with the head raised. In these species, at least part of the foraging process is physically compatible with vigilance. Nevertheless, both vigilance and food handling require […]

Understanding the perceptual world of horses

From the viewpoint of experimental psychology, there are two problems with our current knowledge of equine perception. The first is that the behavioral and neurophysiological research in this area has enormous gaps, reflecting that this animal is not a convenient laboratory subject. The second is that the horse, having been a close companion to humans […]

Laterality and emotions: Visual laterality in the domestic horse (Equus caballus) differs with objects’ emotional value

Lateralization of emotions has received great attention in the last decades, both in humans and animals, but little interest has been given to side bias in perceptual processing. Here, we investigated the influence of the emotional valence of stimuli on visual and olfactory explorations by horses, a large mammalian species with two large monocular visual […]

Perceived differences between chimpanzee (Pan troglodytes) and human (Homo sapiens) facial expressions are related to emotional interpretation

Human face perception is a finely tuned, specialized process. When comparing faces between species, therefore, it is essential to consider how people make these observational judgments. Comparing facial expressions may be particularly problematic, given that people tend to consider them categorically as emotional signals, which may affect how accurately specific details are processed. The bared-teeth […]

Studies on UV reflection in feathers of some 1000 bird species: are UV peaks in feathers correlated with violet-sensitive and ultraviolet-sensitive cones?

Nine hundred and sixty-eight bird species, covering all orders, were studied in search of distinctive ultraviolet reflections. All species in the following orders were completely surveyed: Struthioniformes, Tinamiformes, Craciformes, Turniciformes, Galbuliformes, Upupiformes, Coliiformes, Apodiformes and Musophagiformes. The coloured plumage regions in particular exhibited high proportions of UV-reflecting feathers. Bird orders with species which are believed […]