Jessica Yorzinski

Texas A&M University | TAMU · Department of Ecology and Conservation Biology

Animals selectively direct their visual attention toward relevant aspects of their environments. They can shift their attention using a combination of eye, head, and body movements. While we have a growing understanding of eye and head movements in mammals, we know little about these processes in birds. We therefore measured the eye and head moveme...

The gut microbiome is important for host fitness and is influenced by many factors including the host's environment. Captive environments could potentially influence the richness and composition of the microbiome and understanding these effects could be useful information for the care and study of millions of animals in captivity. While previous st...

Attention can be biased towards previously reward-associated stimuli even when they are task-irrelevant and physically non-salient, although studies of reward-modulated attention have been largely limited to primate (including human and nonhuman) models. Birds have been shown to have the capacity to discriminate reward and spatial cues in a manner...

Background The gut microbiome influences its host in a myriad of ways, from immune system development to nutrient utilization. However, our understanding of the relationship between the gut microbiome and behavior, especially in wild species, is still poor. One behavior that potentially interacts with the gut microbiome is exploratory behavior, whi...

Eyes convey important information about the external and internal worlds of animals. Individuals can follow the gaze of others to learn about the location of salient objects as well as assess eye qualities to evaluate the health, age or other internal states of conspecifics. Because of the increasing prevalence of artificial lighting at night (ALAN...

Animals experience stress throughout their lives and exhibit both physiological and behavioral responses to cope with it. The stress response can become harmful when prolonged and increasing evidence suggests that dopamine plays a critical role in extinguishing the stress response. In particular, activation of the D2 dopamine receptor reduces gluco...

Chimpanzee (Pan troglodytes) sclera appear much darker than the white sclera of human eyes, to such a degree that the direction of chimpanzee gaze may be concealed from conspecifics. Recent debate surrounding this topic has produced mixed results, with some evidence suggesting that (1) primate gaze is indeed concealed from their conspecifics, and (...

Eye gaze is an important source of information for animals, implicated in communication, cooperation, hunting and antipredator behaviour. Gaze perception and its cognitive underpinnings are much studied in primates, but the specific features that are used to estimate gaze can be difficult to isolate behaviourally. We photographed 13 laboratory-hous...

Female competitive behaviors during courtship can have substantial fitness consequences yet we know little about the physiological and social mechanisms underlying these behaviors – particularly for females of polygynous lek mating species. We explored the hormonal and social drivers of female intersexual and intrasexual behavior during courtship b...

In commercial farming systems, chicks are reared without a mother. This absence of maternal influence can cause welfare problems when the chicks become older. Chicks imprint on their mothers they are young, and this mediates their stress and fear response. It is important to recognise problems early in the development of chicks to avoid welfare iss...

Males often exhibit elaborate ornamentation that contributes to their fitness. Similarly, females can also exhibit elaborate ornamentation, but we have a relatively limited understanding of its function. Recent studies have demonstrated that female ornamentation can function in both intrasexual competition and male mate choice, but few studies have...

Even though blinking is necessary to maintain clear vision in many species, blinking is likely costly because it temporarily impairs vision. Given this cost, individuals can strategically modify their blinking behavior to minimize information loss. We tested whether a songbird species modifies its blinking behavior when viewing potential threats (h...

Many species use eye movements to direct their overt attention toward specific targets within their environments. Some species can move each eye independently but we have a limited understanding of whether they can simultaneously monitor different targets with each eye. This study, therefore, tested whether a songbird can independently move its eye...

Species vary widely in the conspicuousness of their eye morphology and this could influence gaze perception. Eyes with conspicuous morphology can enhance gaze perception while eyes with camouflaged morphology may hinder gaze perception. While evidence suggests that conspicuous eye morphology enhances gaze perception, little is known about how envir...

The white sclera is important in facilitating gaze perception in humans. Iris color may likewise influence gaze perception but no previous studies have directly assessed its effect. We therefore examined how the interaction between sclera and iris color influences human gaze perception. We recorded the eye movements of human participants as they pe...

Visual attention plays a fundamental role in avian flight but attention is likely limited whenever birds blink. Because blinks are necessary to maintaining proper vision, this study tested the hypothesis that birds strategically inhibit their blinks in flight. The blinks of captive great-tailed grackles ( Quiscalus mexicanus ) were recorded before,...

Individual predators differ in the level of risk they represent to prey. Because prey incur costs when responding to predators, prey can benefit by adjusting their antipredator behavior based on the level of perceived risk. Prey can potentially assess the level of risk by evaluating the posture of predators as an index of predators’ motivational st...

Gaze perception is an essential behavior that allows individuals to determine where others are directing their attention but we know relatively little about the ways in which eye morphology influences it. We therefore tested whether eyes with conspicuous morphology have evolved to facilitate gaze perception. During a visual search task, we recorded...

Animals often adjust their behavior in response to changes in environmental conditions, and these behavioral adjustments may result from sensory constraints. In particular, rainfall influences behavior but our understanding of its effects on visual abilities is limited. This study, therefore, tested the hypothesis that rainfall influences blinking...

Many animals rely on vision to successfully locomote through their environments. However, our understanding of the interaction between vision and locomotion is surprisingly limited. This study therefore examined the visual mechanisms guiding jumping locomotion in an avian species. It recorded the eye movements of captive Indian peafowl (Pavo crista...

Animals often adjust their behavior and physiology in response to extreme weather. One reason they do so is because weather can cause sensory impairments but our understanding of this topic is limited. We therefore tested whether wind, a common component of extreme weather, impacts sensory systems in captive great-tailed grackles (Quiscalus mexican...

Even prey that successfully evade attack incur costs when responding to predators. These nonlethal costs can impact their reproductive success and survival. One strategy that prey can use to minimize these costs is to adjust their antipredator behavior based on the perceived level of risk. We tested whether humans adopt this strategy by presenting...

Many animals inhabit environments where they experience temperature fluctuations. One way in which animals can adjust to these temperature changes is through behavioral thermoregulation. However, we know little about the thermal benefits of postural changes and the costs they may incur. In this study, we examined the thermoregulatory role of two po...

Behavioral innovations allow animals to adjust their behavior to solve novel problems. While innovative behavior can be important for animals living in new environments, anthropogenic pollution may limit their ability to adapt by impairing cognition or motivation. In particular, exposure to light pollution at night can cause sleep deprivation and m...

Males in many species compete intensely for access to females. In order to minimize costly interactions, they can assess their rivals' competitive abilities by evaluating traits and behaviors. We know little about how males selectively direct their attention to make these assessments. Using Indian peafowl (Pavo cristatus) as a model system, we exam...

Even when animals are actively monitoring their environment, they lose access to visual information whenever they blink. They can strategically time their blinks to minimize information loss and improve visual functioning but we have little understanding of how this process operates in birds. This study therefore examined blinking in freely-moving...

Natural environments are increasingly exposed to high levels of noise pollution. Noise pollution can alter the behavior of animals but we know little about its effects on antipredator behavior. We therefore investigated the impact of noise pollution on vigilance behavior and roost selection in an avian species, peafowl (Pavo cristatus), that inhabi...

Animals of many different species discriminate among individuals based on acoustic properties of vocalizations. These vocalizations are produced in different contexts, including territorial defence and parent–offspring interactions. They are also produced in response to predators, but we know less about whether animals, especially birds, are able t...

Artificial light pollution is drastically changing the sensory environments of animals. Even though many animals are now living in these changed environments, the effect light pollution has on animal behavior is poorly understood. We investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus). Captive peahens were...

Many prey species exhibit defensive traits to decrease their chances of predation. Conspicuous eye-spots, concentric rings of contrasting colours, are one type of defensive trait that some species exhibit to deter predators. We examined the function of eye-spots in Lepidoptera to determine whether they are effective at deterring predators because t...

Animals use vision to gather information about their environment and then use that information to make behavioural decisions that affect fitness. They will often move their heads or eyes to inspect areas of interest with their centres of acute vision, such as foveae, to gather high resolution information about potential mates, predation risks, or o...

Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snak...

Animals emit vocalizations that convey information about external events. Many of these vocalizations, including those emitted in response to predators, also encode information about the individual that produced the call. The relationship between acoustic features of antipredator calls and information relating to signalers (including sex, identity,...

Predation can exert strong selective pressure on the evolution of behavioral and morphological traits in birds. Because predator avoidance is key to survival and birds rely heavily on visual perception, predation may have shaped avian visual systems as well. To address this question, we examined the role of visual attention in antipredator behavior...

There was an error published in J. Exp. Biol. 216, 3035-3046. The authors inadvertently omitted to declare a competing interest for one of the authors. The correct Competing Interests statement is given below. J.S.B. owns the company (Positive Science) that manufactured the eye-tracking headpiece and designed the eye-tracking software, which were u...

Conspicuous, multicomponent ornamentation in male animals can be favored by female mate choice but we know little about the cognitive processes females use to evaluate these traits. Sexual selection may favor attention mechanisms allowing the choosing females to selectively and efficiently acquire relevant information from complex male display trai...

Males often continuously emit vocalizations during the breeding season that attract female mates. They can also emit calls that are specifically associated with copulations but the function of these copulation calls is often unknown. We explored the function of male copulation calls in wild and captive peafowl (Pavo cristatus) to test whether these...

Animals have evolved sophisticated strategies for avoiding predators during the day. These strategies can vary depending on the type of predator and level of threat. Although nocturnal predation is a major cause of animal mortality, antipredator behavior at night is poorly understood. To investigate how diurnal animals adjust their antipredator beh...

Animals are frequently confronted with changing environmental conditions (Houston and McNamara 1992; Komers 1997). When they are no longer exposed to the sources of selection that their ancestors once faced, they experience relaxed selection on these sources (Coss 1999). They may still retain behavior that was shaped to cope with the past selective...

Mate-choice copying occurs when animals rely on the mating choices of others to inform their own mating decisions. The proximate mechanisms underlying mate-choice copying remain unknown. To address this question, we tracked the gaze of men and women as they viewed a series of photographs in which a potential mate was pictured beside an opposite-sex...

Animals in many vertebrate species vocalize in response to predators, but it is often unclear whether these antipredator calls function to communicate with predators, conspecifics or both. We evaluated the function of antipredator calls in 10 species of passerines by measuring the acoustic directionality of these calls in response to experimental p...

Las llamadas de alarma que inducen la huida frecuentemente comunican información sobre el tipo de depredador y el peligro asociado con éste. Sin embargo, se conoce menos sobre como las llamadas de asedio que inducen el acercamiento codifican esta información. Estudiamos las llamadas de asedio de Corvus brachyrhynchos para determinar si estas llamad...

El Llamado Declinado De Alarma De Corvus Brachyrhynchos: Diferencias En La Estructura Acústica Entre Individuos Y Sexos Las investigaciones anteriores sobre las diferencias individuales en la estructura acústica de las vocalizaciones y sobre el reconocimiento individual se han centrado principalmente en los contextos de interacciones entre padres e...

Traits that were adaptive under previous conditions may no longer have fitness benefits. However, some species still retain appropriate antipredator behaviors even though they do not coexist with the predators that their ancestors once faced. Studies have examined the responses of a variety of naïve species to these predators, but none have specifi...

Previous research on individual differences in the acoustic structure of vocalizations and vocal recognition has largely focused on the contexts of parent-offspring interactions, territory defense, sexual interactions, and group cohesion. In contrast, few studies have examined individual differences in the acoustic structure of mobbing and alarm ca...

The functions of two visual signals of the mandrill [silent bared-teeth face (SBTF) and crest-raise (CR)] were investigated by quantifying the probability of each signal occurring across a set of distinct contexts. The motivation for the investigation was twofold: (1) SBTF had been interpreted in diverse and sometimes contradictory ways, and (2) CR...

Predation has likely been a major selective force shaping the evolution of pri- mates. As a result of this current and past force, primates display a variety of antipredator behaviors. Because natural encounters with predators are infre- quently observed, we do not have knowledge about the antipredator behaviors of many primate species. The aim of...

Most mammals are characterized by a lack of parental care by the male sex. This is particularly true in highly polygynous, sexually selected species and species in which fathers remain only weakly associated with their offspring. Here we report observations suggesting the existence of male parental care in the mandrill (Man- drillus sphinx, Primate...