Taste-induced facial expressions are thought to reflect the hedonic valence of an animal’s gustatory experience. We therefore assessed taste-induced facial responses in six black-handed spider monkeys (Ateles geoffroyi) to water, sucrose, caffeine, citric acid and aspartame, representing the taste qualities sweet, bitter, and sour, respectively. We decided not to include salty-tasting substances as

Recognition of mates from others is crucial for monogamous species to maintain their long-term pair bonds. The seahorse is widely recognized as a monogamous species, and its mate recognition cue is still not well understood. In the present study, we used the lined seahorse (Hippocampus erectus) as an experimental animal and investigated the effect of blocking olfactory, visual or behavioral (i.e.,

The ability to extract reliable segments from the sensory data-stream is necessary for learning and for creating a reliable representation of the environment. Here we focused on segmentation in visual learning associated with foraging. Fifty-one pigeons (Columba livia) were trained to recognize two food-predicting signals, one presented against fixed background elements and the other against varying

All animals must move efficiently throughout their world. However, the mechanisms through which they accomplish this potentially vary among species. Previous work exploring the use of feature information and geometric information in movement through space has indicated that geometric information is commonly used and that some species sometimes also use feature information. Here, I investigated if a

Animals avoid predator attack in different ways; some carry defensive structures to reduce predation, with the classic example being hermit crabs and their use of a mollusc shell as a portable refugium. During shell selection, various shell characteristics are investigated by the crab to determine their suitability. Here we consider the role of visual cues. Previous research suggests that some hermit

The strictly monogamous California mouse (Peromyscus californicus) forms life-long pair bonds and mates exclusively with a single partner. While studies in the wild indicate that individuals may re-pair with a new partner following mate loss, the preponderance of this behavior and subsequent reproductive outcomes following re-pairing are understudied. To examine reproductive outcomes following re-pairing

In a signal detection theory (SDT) approach to associative learning, one assumes that, when a subject is exposed to a flow of stimuli, an association is created between the internal representations of a cue and of an outcome, allowing the representation of the cue to activate the representation of the outcome. The outcome activation is a random variable drawn from a Gaussian distribution with mean

Sexually selected traits, including threat signals, have been shown to scale steeply positively with body size because their exaggeration maximizes honest signalling. However, the functional allometry hypothesis makes the opposite prediction for some weapons: because the biomechanics of force applied in their use may favor relatively smaller size, sexually selected weapons may exhibit negative allometry

The Roman-Low (RLA) and High-Avoidance (RHA) rat strains have been bidirectionally selected and bred, respectively, for extremely poor vs. rapid acquisition of the two-way active avoidance task. Over 50 years of selective breeding have led to two strains displaying many differential specific phenotypes. While RLAs display anxious-related behaviours, RHA rats show impulsivity, and schizophrenia-like

Prosocial behaviours (providing benefits to a recipient with or without cost for the donor) have been found to be highly influenced by sex and by hierarchy. Rodents, in particular, are good model for studying prosocial responses, as they were found to exhibit intentional prosocial behaviours to reward a conspecific, and are very sensitive to reciprocity. In our study, we conducted a Prosocial Choice

Results of studies examining the relationship between impulsivity and age are limited because different tasks, procedural parameters, and different reinforcers have been used with different aged participants. Thus, the current study sought to rectify these differences in two experiments with children (42, ages 5–12) and adults (69 college-aged females) using the same task with identical procedural

Sexual cannibalism is an extreme form of sexual conflict that may have broad evolutionary effects on mating behaviour. Latrodectus spiders (∼30 “widow” species) could enable comparative tests of the evolution of sexual cannibalism, but most species are poorly-studied. Here we describe the mating and remating behaviour of a species endemic to South America, L. mirabilis, with a focus on the occurrence

A wide range of animal species accumulate objects in, on, and/or around structures they build. Sometimes, these accumulations serve specific functions (e.g. structural or isolating features) or are purely incidental, while in other cases the materials are deliberately displayed to serve signalling purposes (extended phenotype signals). In this pilot study, we employed systematic in situ observations

Two experiments, using rats as the subjects, and flavour aversion learning with an injection of lithium chloride (LiCl) as the unconditioned stimulus (US), examined the effects of a context shift between phases of the procedure on the retardation of learning produced by preexposure to the US. Experiment 1 showed that the US-preexposure effect (the reduction in the size of the conditioned aversion)

Right-handedness in humans reflects the functional brain specialisation of the left hemisphere. To better understand the origins of this population-level tendency, it is crucial to understand manual lateralisation in other non-human primate species. The aim of this article is to present a first approach to the hand preference of two primates from Vietnam, the endangered hatinh langur (Trachypithecus

Adolescence is a period of increased sensitivity to stress and vulnerability to the manifestation of psychiatric disorders, such as attention-deficit/hyperactivity disorder (ADHD). Nevertheless, the relationship between stress during adolescence and ADHD is still unclear. Knowing that stress can have long-term consequences, the aim of this study was to evaluate the impact of a single episode of restraint

In this field experiment, we presented pairs of monogamous convict cichlids with different intruders (conspecific and either cichlid or non-cichlid heterospecific) and observed the aggressive behavior of the pair to determine if pairs adjust aggression based upon species of intruder. We predicted that pairs would be more aggressive to conspecifics as these intruders represent multiple threats. The

Hemispheric lateralization is a specialized neural and cognitive processing achieved preferentially by either the left or the right hemisphere of the brain. Among vertebrates, emotions processing seems to be lateralized, but the involvement of each hemisphere is still on debate. Our study investigated visual and motor laterality on five bottlenose dolphins’ (Tursiops truncatus) during spontaneous and

Warning coloration deters predators from attacking unpalatable prey, and is often characterized by long-wavelength colors, such as orange and red. However, warning colors in nature are more diverse and include short-wavelength colors, like blue. Blue has evolved as a primary defense in some animals but is not common. One hypothesis for the maintenance of this diversity is interspecific variation in

In one experiment with rats, we examined whether positive affective states can serve as contexts in a between-subjects ABA renewal design using appetitive instrumental conditioning. Two groups of rats received training to press a lever for food where each acquisition session was preceded by administration of a tickling procedure (Context A) known to induce positive affective states. Then, lever pressing

Associations between alcohol and the places it is consumed are important at all stages of alcohol abuse and addiction. However, it is not clear how the associations are formed in humans or how they influence drinking, and there are few effective strategies to prevent their pathological effects on alcohol use. We used a human laboratory model to study the effects of alcohol environments on alcohol consumption

Assessments for behavioral inhibition in pet dogs that can rapidly detect age-related cognitive deficits (ARCD) using inexpensive and accessible materials may aid in diagnosing canine dementia and may facilitate translational research on Alzheimer’s disease in humans. In this study, we designed and deployed a spatial serial reversal learning test in which 80 pet dogs were required to learn which of

Research suggests that predation risk during adolescence can program adult stress response and emotional behavior; however, little is known about the short-term and lasting residual effects of this experience on social behavior. We explored this concept in social Brandt’s voles (Lasiopodomys brandtii). Adolescent male and female voles were exposed to distilled water, rabbit urine (as a non-predator

Foraging ants use multiple navigational strategies, including path integration and visual panorama cues, which are used simultaneously and weighted based upon context, the environment and the species’ sensory ecology. In particular, the amount of visual clutter in the habitat predicts the weighting given to the forager’s path integrator and surrounding panorama cues. Here, we characterize the individual

Response force is a fundamental dimension of behavior. Yet, little is known about its functional significance for learning. The present review examines the behavioral effects of force across several domains. Along the way, advantages of different measurement strategies that have been used to study force are evaluated. The behavioral functions of force are also considered in light of two commonly expressed

Reinforcement learning is often described by analogy to natural selection. However, there is no coherent theory relating reinforcement learning to evolution within a single formal model of selection. This paper provides the formal foundation of such a unified theory. The model is based on the most general description of natural selection as given by the Price equation. We extend the Price equation

Delay discounting (DD) refers to the decrease in the subjective value of a reward as the delay to its receipt increases. As high rates of DD are consistently associated with measures of substance misuse, DD is an important construct in current conceptualizations of addiction. High rates of DD appear to model preference for the immediate rewards provided by substance use, resulting in the interpretation

This study replicated and extended previous research (Bloom & Friedman, 2013) indicating that humans can correctly identify emotional expressions in photographs of dog faces when tested with one breed (i.e., a Malinois). It examined the effect of dog facial morphology on accuracy of emotion identification by using images of a Malinois, as well as two-different breeds (Doberman and Rhodesian Ridgeback)

Animal-borne video loggers are powerful tools for investigating animal behaviour because they directly record immediate and extended peripheral animal activities; however, typical video loggers capture only a limited area on one side of an animal being monitored owing to their narrow field of view. Here, we investigated the resting behaviour of humpback whales using an animal-borne omnidirectional

Spatial discounting is a largely underexplored area of decision-making research, both theoretically and empirically, especially when compared to intertemporal choice, which has received significant attention in psychology and animal behaviour. Spatial decision problems seem to share some of the same features of a temporal decision problem (namely, the risk of reward objects disappearing and the opportunity

Personality is not a uniquely human characteristic and it has been documented in a wide range of organisms, from mammals to birds, reptiles, fish, and invertebrates. However, personality is still poorly understood in Cervids. Therefore, our study aimed to fill this gap by i) investigating personality and ii) exploring its links to dominance hierarchy, assessed by behavioral observations in 11 captive

The demand for opioid medication to effectively treat pain has contributed to the surging opioid crisis, which is a major source of morbidity and mortality in the U.S. More than 100,000 people begin opioid maintenance treatment (OMT) annually, the standard pharmacotherapy for opioid use disorder (OUD). Although OMT is the standard care for OUD, patients often experience or develop a heightened sensitivity

Prey animals may react differently to predators, which can thus raise plasticity in risk-taking behaviour. We assessed the behavioural responses of nestling-feeding collared flycatcher (Ficedula albicollis) parents towards different avian predator species (Eurasian sparrowhawk, long-eared owl) and a non-threatening songbird (song thrush) by measuring the latency to resume feeding activity. We found

Synchronous behaviours occur when two or more animals display the same behaviour at the same time. However, the mechanisms underlying this synchrony are not well understood. In this study, we carried out an experiment to determine whether or not Bottlenose dolphins use acoustic cues when performing a known synchronised exercise. For this, we recorded three dolphins while they performed requested aerial

Researchers have employed a variety of laboratory analogues of cryptic prey detection and applied signal detection to study factors influencing learning and performance in these ethological and applied scenarios. However, these procedural analogues do not appear to map closely onto their “real-world” counterparts, particularly with respect to the role of the “yes” (i.e., “attack”) response and the

Many recent studies show that synchronisation of various behaviours are advantageous for group-living mammals. However, studies on synchronisation of suckling behaviour inmonotocous species are nearly absent. We observed 49 individual foals of three zebra species in Dvůr Králové Zoo, and recorded a total of 5 890 suckling bouts, almost one fifth (1 036) of which were synchronised (defined as at least

The present study examined different conditions under which exclusion responding in conditional discrimination tasks would generate emergent equivalence relations in young children based on shared relationships with verbal labels. Both visual stimuli (Sets A, B, C, and D) and auditory stimuli (spoken words, Set N: N1 “correct”; N2: “incorrect”) were used. Following a pilot study, three experiments

In the current research, we aimed at extending Silveira et al. (2016) results by verifying whether the long-term maintenance of the equivalence classes is influenced by stimulus valence and MTS training procedures. The delayed and simultaneous MTS were used to train two groups of participants in series of conditional relation trials involving pictures of humans’ faces expressing familiar emotions (A)

Although the contact calls of birds have been studied for their acoustic properties, limited research has investigated their repetitive nature. The rate of contact calls could be related to movement, with recruiting birds signalling their location, or it could help maintaining spacing between group mates, or give information about the environment where both signaller and receiver are located. If maintaining

Behavioural lateralization, the differential use one side of the body, and/or the bilateral use of sensory organs or limbs, is common in many vertebrates. One way in which behavioural lateralization can be detected in animals is through turning biases, which is an inherent preference to either turn left or right. Mole-rats are a unique group of mammals that demonstrate a wide range of social organizations

Two of the main hypotheses put forth to explain the function of immature social play are the Social Skill Hypothesis and the Motor Training Hypothesis focussing on whether play can improve social competence to develop cooperative social networks or physical abilities to outcompete others, respectively. Here, we tested these hypotheses on a monkey species, the wild gelada (Theropithecus gelada) from

Observational studies in the wild suggest that birds select material to build their nests based on functional aspects of material that promote reproductive success. How birds select material for nest building from the variety of materials available in their environment is unclear. In the current laboratory experiment we manipulated breeding success (i.e. raising fledglings) of zebra finch (Taeniopygia

‘Winner’ and ‘loser’ effects have been demonstrated in a broad range of species, but such investigations are often limited to the effects of prior contest outcomes on future agonistic interactions. Much less is known about the impacts of winning or losing contests on other aspects of individual behavior, like courtship interactions and sheltering behavior. In this investigation, I examined the effect

Adult females and males live apart outside the mating period in many social vertebrates, but the causes of this phenomenon remain a matter of debate. Current prevailing hypotheses predict no sexual segregation outside the early period of maternal care in nearly monomorphic species such as the Pyrenean chamois (Rupicapra pyrenaica). We examined sexual segregation in a population of the species, using

Two Pavlovian appetitive conditioning experiments with rats assessed extinction cue (EC) transfer using spontaneous recovery tests. In each experiment, after conditioned stimulus (CS) A-US pairings, an EC (X) was presented during A-extinction, followed by spontaneous recovery testing with A. Experiment 1 tested for transfer between ECs; the additional CS (B) was conditioned and then was extinguished

Novelty recognition helps organisms identify changes over time. Studies to date have usually involved mammals, particularly rodents. We explored leopard geckos’ (Eublepharis macularius; Experiment 1) and tiger salamanders’ (Ambystoma tigrinum, Experiment 2) sensitivity to spatial and object novelty. We used an exploratory paradigm adapted from rodents where time spent near objects in an open-field

Animal signals in multiple modalities expands the opportunity for effective communication. Among diurnal geckos of the genus Cnemaspis, chemical signalling traits preceded the evolution of visual traits. Males of all species possess chemical secreting ventral glands, but only in some species, males also express yellow gular patches. This difference in the expression of unimodal or multimodal signalling

Despite the prevalence and research interest of animal personality, its underlying mechanisms are not yet fully understood. Due to the essential role of monoamines in modulating behaviour, we manipulated the monoaminergic systems of Mediterranean field crickets (Gryllus bimaculatus) to explore whether this altered behavioural responses commonly used to describe animal personality. Previous work has

Intraspecific interactions among predators can change the game between a predator and its prey. Individuals of different size or sex can differ in their responses to conspecific competitors. We studied intraspecific interactions among pairs of little egrets (Egretta garzetta) while foraging on responsive prey (comet goldfish, Carassius auratus). Testing little egrets in an artificial patchy environment

In social species such as house mouse, being dominant is vital. Determination of dominance may start early in life and vary during ontogeny. We asked whether pre-pubertal and adolescent behaviour predicts the rank a male mouse finally obtains. Moreover, we asked how dominant vs. subordinate adults differ in exploration and propensity to emigrate. We studied fraternal pairs as the simple social units

Planarians are freshwater flatworms commonly used as environmental bioindicator due to their sensitivity of response and their ease of culturing in lab. Nevertheless, to date, very few studies describing their behavior have been led. This work aims to fill the literature gap by providing preliminary results through six behavioral challenges (locomotion, exploration, light stress, planarian light/dark

Chemical communication is important for mate choice, especially at long distances in fragmented populations. The gopher tortoise is a social species that is threatened in the southeast U.S. due to habitat fragmentation and decline. One consequence of habitat loss is reduced mating opportunities, yet chemical signalling in gopher tortoises is relatively under-studied. Here, we investigated chemoreception

Reproductive investment was initially thought to be the key selective force behind male mate preference for female characters, like size or ornamentation (i.e., the preference by males for certain females). Yet, evidence of polygynous species, where male reproductive investments are often inexpensive compared to those of females, have also been described to possess male preference. Our study aims to