The Yorzinski Lab at Texas A&M University in the Department of Ecology and Conservation Biology is focused on understanding animal behavior, with an emphasis on sensory ecology, animal communication, and conservation. We adopt an interdisciplinary approach to investigating the mechanisms that shape the form and function of diverse signals.
Visual Attention in Birds and Primates
Animals are continuously bombarded with visual information from their environment. Due to neural processing limitations, animals must selectively filter this information by directing their attention to relevant information while ignoring the rest. We study how animals employ visual attention in complex sensory environments to make decisions that influence their survival and reproduction.
Acoustic Communication in Birds
Animals can encode detailed information in their vocalizations. These vocalizations can inform conspecifics about the identity, age, and sex of callers. They can also communicate the presence and danger level of predators. We study how animals use vocalizations to communicate with each other about their internal and external environments.
Nocturnal Antipredator Behavior in Peafowl
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 behavior during these different conditions, we exposed peahens to a taxidermy raccoon during the daytime and nighttime. During the day, the peahens emitted loud antipredator calls, extended their necks upward, adopted a preflight posture, and approached the predator; at night, the peahens emitted soft hissing calls, remained stationary, piloerected their feathers, and raised their tails. The results demonstrate that birds adopt radically different antipredator behavior depending on whether the threat occurs in the daytime or nighttime. Videos showing nocturnal and diurnal antipredator behavior of peafowl (Pavo cristatus) are available online.
Acoustic Directionality in Songbirds
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 songbirds by measuring the acoustic directionality of these calls in response to experimental presentations of a model predator. Acoustic directionality quantifies the radiation pattern of vocalizations and may provide evidence about the receiver of these calls. Overall, the birds produce antipredator calls that have a relatively low directionality, suggesting that the calls radiate in many directions to alert conspecifics. However, birds in some species increase the directionality of their calls when facing the predator. They can even direct their calls towards the predator when facing lateral to it—effectively vocalizing sideways towards the predator.
Anthropogenic Disturbances and Behavior
Humans are increasingly impacting the natural world and these impacts can have dramatic effects on the behavior of animals. Light and noise pollution, for example, can alter the sensory world of animals and influence how they respond to predators and mates. We study the ways in which anthropogenic disturbances influence animal behavior.
Artificial Light Pollution and Problem-solving Success in Peafowl
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 may, therefore, hinder innovative behavior. To test this hypothesis, we examined experimentally whether exposure to acute light pollution impacts problem-solving success in peafowl (Pavo cristatus). We found that their problem-solving success was unrelated to short-term light pollution exposure. Other factors, including persistence, sex of the bird, and moon illumination, influenced their success in solving the task. The results suggest that short-term exposure to light pollution does not limit behavioral innovation, but long-term studies are necessary to further probe this question.
Artificial Light Pollution Increases Nocturnal Vigilance in Peahens
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. With a team of undergraduates (Sydney Byerley, Jeanee Coy, Aisyah Aziz, Jamie Wolf, and Amanda Gnerlich), we investigated the effect of light pollution on nocturnal vigilance in peahens (Pavo cristatus). We found that light pollution significantly increases nocturnal vigilance in peahens. Furthermore, the birds faced a trade-off between vigilance and sleep at night: peahens that were more vigilant spent less time sleeping. Given the choice, peahens preferred to roost away from high levels of artificial lighting but showed no preference for roosting without artificial lighting or with low levels of artificial lighting. Our study demonstrated that light pollution can have a substantial impact on animal behavior that can potentially result in fitness consequences.
A Songbird Inhibits Blinking Behaviour in Flight
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, we tested the hypothesis that birds strategically inhibit their blinks in flight. The blinks of captive great-tailed grackles (Quiscalus mexicanus) were recorded before, during and after they flew a short distance in an open environment. The grackles spent the least amount of time blinking in flight (take-off, during flight and landing) and the most amount of time blinking at impact. Their blinking behaviour was similar before and after flight. These results suggest that grackles strategically inhibit their blinking behaviour in flight, potentially because blinks impose costs to avian flight.
Mate-choice Copying in Humans
Mate-choice copying occurs when animals rely on the mating choices of others to inform their own mating decisions but 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 partner; the participants then indicated their willingness to engage in a long-term relationship with each potential mate. We found that both men and women expressed more interest in engaging in a relationship with a potential mate if that mate was paired with an attractive partner. Men and women’s attention to partners varied with partner attractiveness and this gaze attraction influenced their subsequent mate choices. These results highlight the prevalence of non-independent mate choice in humans and implicate social attention and reward circuitry in these decisions.