In Ovo Olfactory Experience Influences Post-hatch Feeding Behaviour in Young Chickens

Does Maternal Diet Influence Future Infant Taste and Odor Preferences? A Critical Analysis

The dietary choices a mother makes during pregnancy offer her developing fetus its earliest exposure to the family's culinary preferences. This comprehensive literature review synthesizes five decades of research, which has provided valuable insights into fetal flavor learning. Converging evidence across various species supports the functionality of fetal chemoreceptive systems by the end of gestation, enabling the detection of an extensive array of chemosensory cues derived from the maternal diet and transmitted to the amniotic fluid. The fetus effectively encodes these flavors, resulting in their enhanced acceptance after birth. While existing studies predominantly concentrate on fetal learning about odor volatiles, limited evidence suggests a capacity for learning about gustatory (i.e., taste) properties. Examining whether these prenatal odor, taste, and flavor experiences translate into enduring shifts in dietary behaviors beyond weaning remains a crucial avenue for further investigation.

Perspectives on chick embryo models in developmental and reproductive toxicity screening

Teratology, the study of congenital anomalies and their causative factors intersects with developmental and reproductive toxicology, employing innovative methodologies. Evaluating the potential impacts of teratogens on fetal development and assessing human risk is an essential prerequisite in preclinical research. The chicken embryo model has emerged as a powerful tool for understanding human embryonic development due to its remarkable resemblance to humans. This model offers a unique platform for investigating the effects of substances on developing embryos, employing techniques such as ex ovo and in ovo assays, chorioallantoic membrane assays, and embryonic culture techniques. The advantages of chicken embryonic models include their accessibility, cost-effectiveness, and biological relevance to vertebrate development, enabling efficient screening of developmental toxicity. However, these models have limitations, such as the absence of a placenta and maternal metabolism, impacting the study of nutrient exchange and hormone regulation. Despite these limitations, understanding and mitigating the challenges posed by the absence of a placenta and maternal metabolism are critical for maximizing the utility of the chick embryo model in developmental toxicity testing. Indeed, the insights gained from utilizing these assays and their constraints can significantly contribute to our understanding of the developmental impacts of various agents. This review underscores the utilization of chicken embryonic models in developmental toxicity testing, highlighting their advantages and disadvantages by addressing the challenges posed by their physiological differences from mammalian systems.

Impact of natural and artificial prenatal stimulations on the behavioural profile of Japanese quail

As the sensory systems of vertebrates develop prenatally, embryos perceive many environmental stimuli that can influence the ontogeny of their behaviour. Whether the nature and intensity of prenatal stimuli affect differently this ontogeny remains to be investigated. In this context, this study aimed to analyse the effects of prenatal auditory stimulations (natural stimulations "NS": predator vocalisations, or artificial stimulations "AS": metallic sounds) on the subsequent behaviour of young Japanese quail (Coturnix coturnix japonica). For that, behavioural variables recorded during ethological tests evaluating emotional and social reactivity were analysed using a principal component analysis. This analysis revealed significant differences between the behavioural profile of stimulated chicks and that of non-exposed chicks. Indeed, chicks exposed to NS expressed more intense emotional responses in fearful situations, but less neophobia in the presence of a novel environment or object, whereas chicks exposed to AS appeared more sensitive to social isolation. Our original results show that the acoustic environment of embryos can influence the way young birds subsequently interact with their social and physical environment after hatching, and face challenges in changing living conditions.

Towards the prediction of feed intake capacity of modern broilers on bulky feeds

The use of alternative, often bulky ingredients is becoming widespread in poultry diets as the industry seeks to reduce its economic and environmental costs. Consequently, there is an increased need to accurately predict the performance of birds given such diets and identify their maximum capacity for bulk. We offered diets diluted with a range of bulky ingredients to male Ross 308 broilers to assess their capacity for bulk and identify a bulk characteristic responsible for limiting intake. Four hundred ninety-five day-old broilers allocated into 45 pens, were offered a common starter diet until day (d) 7, and 1 of 9 grower diets from d 8 to 29 (Period 1). Each of the grower diets was diluted with either 30 or 60% of oat hulls (OH), wheat bran (WB), or grass meal (GM), or a mixture of 2 bulky ingredients at an inclusion level of 30% each (OHWB, OHGM, WBGM). From d 29 to 43 (Period 2), all birds were offered the bulkiest diet (GM60). A number of bulk characteristics were measured on the diets. Feed intake was measured daily, and birds were dissected on d 29 and 43 for organ and carcass measurements. During d 8 to 14 diet water-holding capacity (WHC) was more consistent in predicting feed intake when scaled per unit of body weight than any other bulk characteristic. However, this was no longer the case during d 15 to 28. In Period 2, the response and adaptation to the bulkiest diet was determined by previous experience to bulk. Birds offered a bulkier diet during Period 1, were better able to adapt the size of their digestive organs and increase scaled feed intake, such that there were no differences between these birds and those offered the GM60; the converse was the case for birds on the least bulky diets. We conclude that WHC is able to predict maximum intake on bulky diets in unadapted birds. Adaptation to bulky diets can be very fast, so that their high bulk content no longer limits feed intake and performance.

Review: Management of livestock behavior to improve welfare and production

In animal production, producers face different problems inherent to production systems. Today society is increasingly concerned about more sustainable systems and animal welfare. Applied ethology can be a tool to solve some of these problems through these approaches. The purpose of this review is to show succinctly some sustainable behavioral technologies whose application favors animal welfare and productivity. The examples cover areas of behavioral problems associated with multiple births, where odor transfer can be used to substitute or add newborns to a foster mother; early weaning, where some alternatives for a gradual break may reduce the stress of separation; early experience on the development of food preferences, where behavioral problems like neophobia can be avoided; early detection of sick animals, where recognition of some specific behaviors could help early identification of diseases, even before the appearance of clinical signs; social isolation on ease of handling, where different techniques have proved their effectiveness modifying the temperament of the animals; design of facilities and management, where it is highlighted how when considering the behavior of the animals in the design and management, better results are obtained; social isolation, facilitation, and buffering, where the presence of other members of the group can modify the consumption and sexual behaviors of pen-mates, or even alleviate suffering; and human-animal interaction on productivity, where the relevance of a positive human-animal interaction is highlighted. After reviewing the scientific literature on the subject, we can conclude that several modern livestock management practices might induce stress in animals, affecting their welfare, health, and productive performance. Applied animal behavior could be a sustainable and effective option to understand and solve some of these problems, and in many cases does not even require a strong economic investment for producers.

Female-Based Patterns and Social Function in Avian Chemical Communication

Much of the growing interest in avian chemical signals has focused on the role of kin recognition or mate attraction, often with an emphasis on males, with uropygial gland secretions perhaps providing information about an individual's identity and quality. Yet, data collected to date suggest sexual dimorphism in uropygial glands and secretions are often emphasized in female, rather than in male birds. That is, when a sexual difference occurs (often during the breeding season only), it is the female that typically exhibits one of three patterns: (1) a larger uropygial gland, (2) a greater abundance of volatile or semi-volatile preen oil compounds and/or (3) greater diversity of preen oil compounds or associated microbes. These patterns fit a majority of birds studied to date (23 of 30 chemically dimorphic species exhibit a female emphasis). Multiple species that do not fit are confounded by a lack of data for seasonal effects or proper quantitative measures of chemical compounds. We propose several social functions for these secretions in female-based patterns, similar to those reported in mammals, but which are largely unstudied in birds. These include: (1) intersexual advertisement of female receptivity or quality, including priming effects on male physiology, (2) intrasexual competition, including scent marking and reproductive suppression or (3) parental behaviors, such as parent-offspring recognition and chemical protection of eggs and nestlings. Revisiting the gaps of chemical studies to quantify the existence of female social chemosignals and any fitness benefit(s) during breeding are potentially fruitful but overlooked areas of future research.

Artificial milk preference of newborn lambs is prenatally influenced by transfer of the flavor from the maternal diet to the amniotic fluid

The present study examined in lambs whether exposure to flavors derived from pregnant mother's diet and transferred to amniotic fluid (AF) could induce a preference for artificial milk containing one of these flavors. To test this hypothesis, cumin was added to the maternal diet in the last month of gestation. Preference for artificial milk containing p-cymene, one of the chemosensory compounds of cumin, was tested within the first two days after birth in maternally deprived lambs born from mothers fed a cumin-flavored diet (Cumin group), or an unflavored diet (Control group). Aromatic profile of AF from cumin-fed mothers was analyzed by GC-MS/MS to determine whether p-cymene could be detected. While the control group avoided the flavored artificial milk on day 1, the Cumin group did not and showed a preference for the cumin-scented formula on day 2. GC-MS/MS profile of AF revealed that four of the main volatile cumin compounds, p-cymene, p-cymenene, β-pinene and γ-terpinene were present in variable amounts in all samples, p-cymene being the most frequently detected. These findings indicate that newborn lambs can memorize flavors from the mother's diet present in AF and that prenatal experience influences their preference for an artificial milk containing one specific flavor.

Birds and Dogs: Toward a Comparative Perspective on Odor Use and Detection

While canines are generally considered the gold standard for olfactory detection in many situations other animals provide alternatives and offer a unique opportunity to compare biological detection capabilities. Critical components in successfully studying biological detectors is not only understanding their anatomical evidence for olfaction, but also, understanding the life history of the species to better direct the potential of an olfactory task. Here, a brief overview is provided presenting a comparative viewpoint on the use of odors by birds and canines over a range of unique detection scenarios. Similar to canines, birds use olfactory information in various natural oriented contexts where odors are dispersed over a widespread spatial range. Comparing these two distinctive animal models, and current trends in physiological and behavioral assessments may open the door for novel uses of birds as biological sensors in forensic applications.

Zebra Finch chicks recognise parental scent, and retain chemosensory knowledge of their genetic mother, even after egg cross-fostering

Mechanisms underlying parent-offspring recognition in birds have fascinated researchers for centuries. Yet, the possibility that chicks recognise parental odour at hatching has been completely overlooked, despite the fact that olfaction is one of the first sensory modalities to develop, and social chemosignals occur in avian taxa. Here we show that Zebra Finch chicks (Taeniopygia guttata) are capable of identifying parental odours at hatching. In our first experiment, chicks begged significantly longer in response to the odour of their genetic mother or father compared to the odour of a non-relative of the same sex and reproductive status. In a second experiment, we cross-fostered eggs and tested the response of hatchlings to the scent of genetic vs. foster parents. Chicks from cross-fostered eggs responded significantly more to the odour of their genetic mother than their foster mother, but exhibited no difference in response to genetic vs. foster fathers. This is the first evidence that embryonic altricial birds are capable of acquiring chemosensory knowledge of their parents during early development, and retain chemical familiarity with their genetic mother despite egg cross-fostering. Furthermore our data reveals that kin recognition in birds can develop without any association with a genetic parent at hatching.

Lipids in maternal diet influence yolk hormone levels and post-hatch neophobia in the domestic chick

We assessed whether the ratio of dietary n-6/n-3 polyunsaturated fatty acids (PUFA) during egg formation engenders transgenerational maternal effects in domestic chicks. We analyzed yolk lipid and hormone concentrations, and HPA-axis activity in hens fed a control diet (high n-6/n-3 ratio) or a diet enriched in n-3 PUFAs (low n-6/n-3 ratio) for 6 consecutive weeks. Their chicks were tested for neophobia during the first week of life. We found higher corticosterone metabolites in droppings of hens fed the diet enriched in n-3 and significantly higher concentrations of yolk progesterone, androstenedione, and estradiol in their eggs compared to controls. Chicks of hens fed the n-3 enriched diet showed a lower body mass at hatch than controls and expressed higher neophobia when exposed to a novel object. These results add support to the hypothesis that the nutritional state of female birds produces variation in yolk hormone levels and engender maternal effects.

Embryonic exposure of chicken chicks (Gallus gallus domesticus) leads to heightened sensitivities towards the exposed scent

In chickens, food consumption can be altered by exposing the chicks to scents as embryos. We exposed eggs to an orange-scented food additive in the final days of incubation. Following hatching, we tested these exposed chicks’ ability to detect this scent at a variety of concentrations. We found that orange-exposed chicks responded to an orange-scented solution at lower concentrations than control chicks. This sensitization may allow chicks to be more effective at locating acceptable food items but requires further testing to determine its significance. Orange-exposed and control chicks were also tested with the scent of raspberry. Orange-exposed chicks responded to the raspberry presentation significantly more than the control chicks did, suggesting that the embryonic exposure to orange may have influenced how the chicks responded towards another fruity smell. This result suggests that chicks may be learning general characteristics of exposed scents while in the egg, though this needs further research.

Behavioral development in embryonic and early juvenile cuttlefish (Sepia officinalis)

Though a mollusc, the cuttlefish Sepia officinalis possesses a sophisticated brain, advanced sensory systems, and a large behavioral repertoire. Cuttlefish provide a unique perspective on animal behavior due to their phylogenic distance from more traditional (vertebrate) models. S. officinalis is well-suited to addressing questions of behavioral ontogeny. As embryos, they can perceive and learn from their environment and experience no direct parental care. A marked progression in learning and behavior is observed during late embryonic and early juvenile development. This improvement is concomitant with expansion and maturation of the vertical lobe, the cephalopod analog of the mammalian hippocampus. This review synthesizes existing knowledge regarding embryonic and juvenile development in this species in an effort to better understand cuttlefish behavior and animal behavior in general. It will serve as a guide to future researchers and encourage greater awareness of the utility of this species to behavioral science.

Chronic odorant exposure upregulates acquisition of functional properties in cultured embryonic chick olfactory sensory neurons

Neuronal development and differentiation is modulated by activity-dependent mechanisms that stimulate endogenous neurogenesis and differentiation to promote adaptive survival of the organism. Studies on bird odor imprinting have shown how sensory stimuli or environmental influences can affect neonatal behavior, presumably by remodeling the developing nervous system. It is unclear whether these changes originate from the sensory neurons themselves or from the brain. Thus, we attempted to address this by using an in vitro system to separate the peripheral neurons from their central connections. Olfactory neurons from embryonic day 17 Gallus domesticus chicks were isolated, cultured, and exposed to 100 µM amyl acetate or phenethyl alcohol in 12-hr bouts, alternated with periods of no-odor exposure. On days 4 and 5 in vitro, cells were immunostained for olfactory marker protein, neuron-specific tubulin, and olfactory GTP-binding protein, and tested for odorant sensitivity using calcium imaging. While odorant exposure did not result in a significant increase in the overall number of neurons, it promoted neuron differentiation: a larger proportion of odorant-exposed cells expressed olfactory marker protein and the olfactory GTP-binding protein. When cell responsiveness was tested using calcium imaging, a greater proportion of odorant-exposed cells responded to stimulation with 100 µM amyl acetate or phenethyl alcohol. Thus, odorant exposure during development modulated the developmental trajectories of individual neurons, resulting in changes in protein expression associated with odorant signaling. This suggests that the neuronal changes in the periphery have an important contribution to the overall long-term functional changes associated with odor imprinting. © 2016 Wiley Periodicals, Inc.

Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks

In this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones-treated eggs (HO) as well as sham embryos (O) that had received the vehicle-only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3-min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non-odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24-h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors.

The perfume of reproduction in birds: chemosignaling in avian social life

This article is part of a Special Issue "Chemosignals and Reproduction". Chemical cues were probably the first cues ever used to communicate and are still ubiquitous among living organisms. Birds have long been considered an exception: it was believed that birds were anosmic and relied on their acute visual and acoustic capabilities. Birds are however excellent smellers and use odors in various contexts including food searching, orientation, and also breeding. Successful reproduction in most vertebrates involves the exchange of complex social signals between partners. The first evidence for a role of olfaction in reproductive contexts in birds only dates back to the seventies, when ducks were shown to require a functional sense of smell to express normal sexual behaviors. Nowadays, even if the interest for olfaction in birds has largely increased, the role that bodily odors play in reproduction still remains largely understudied. The few available studies suggest that olfaction is involved in many reproductive stages. Odors have been shown to influence the choice and synchronization of partners, the choice of nest-building material or the care for the eggs and offspring. How this chemical information is translated at the physiological level mostly remains to be described, although available evidence suggests that, as in mammals, key reproductive brain areas like the medial preoptic nucleus are activated by relevant olfactory signals. Olfaction in birds receives increasing attention and novel findings are continuously published, but many exciting discoveries are still ahead of us, and could make birds one of the animal classes with the largest panel of developed senses ever described.

Maternal diet influences offspring feeding behavior and fearfulness in the precocial chicken

Background

In chicken, oils in the maternal diet confer a specific scent to the yolk. Embryos are known to perceive and memorize chemosensory signals of the surrounding environment; however, the potential impact of the maternal diet has not previously been investigated. In the present study, we hypothesized that chicken embryos memorize the chemical signals of the maternal diet and that this perceptual learning may orient subsequent feeding behavior of the hatchlings.

Methodology/Principal Findings

Laying hens were fed standard food enriched with 2% menhaden oil (MH group) or 2% soybean oil (controls). The scent of menhaden was significantly more detected in MH egg yolks than in control yolks by a human panel. We analyzed the development and behavior of offspring towards different types of food, bearing or not bearing the menhaden scent. When chicks were exposed to a 3-min choice test between the familiar food bearing the menhaden scent and the familiar food without menhaden, no effect of treatment was observed. In a 3-min choice test with unfamiliar food (mashed cereals) MH chicks showed a clear positive orientation toward the unfamiliar food bearing the menhaden scent. By contrast, control chicks showed a preference for the non-odorized unfamiliar food. MH chicks expressed higher emotional reactivity level than control chicks as expressed by food neophobia and longer immobility in a restraint test.

Conclusion/Significance

Chicks exposed in ovo to menhaden oil via the maternal diet preferentially oriented their feeding behavior towards food containing menhaden oil, but only when the food was unfamiliar. We propose that oil in the maternal diet engenders maternal effects and contributes to the development of behavioral phenotype in the offspring. In ovo chemosensory learning may have evolved to prepare precocial offspring for their environment. This suggests a common principle of embryonic chemosensory learning across vertebrate taxa.

Moderate heat challenge increased yolk steroid hormones and shaped offspring growth and behavior in chickens

Background

Environmental challenges might affect the maternal organism and indirectly affect the later ontogeny of the progeny. We investigated the cross-generation impact of a moderate heat challenge in chickens. We hypothesized that a warm temperature–within the thermotolerance range- would affect the hormonal environment provided to embryos by mothers, and in turn, affect the morphology and behavioral phenotype of offspring.

Methodology/Principal Findings

Laying hens were raised under a standard thermal condition at 21°C (controls) or 30°C (experimental) for 5 consecutive weeks. A significant increase was observed in the internal temperature of hens exposed to the warm treatment; however plasma corticosterone levels remained unaffected. The laying rate was not affected, but experimental hens laid lighter eggs than the controls during the treatment. As expected, the maternal thermal environment affected yolk hormone contents. Eggs laid by the experimental hens showed significantly higher concentrations of yolk progesterone, testosterone, and estradiol. All chicks were raised under standard thermal conditions. The quality of hatchlings, growth, feeding behavior and emotional reactivity of chicks were analyzed. Offspring of experimental hens (C30 chicks) were lighter but obtained better morphological quality scores at hatching than the controls (C21 chicks). C30 chicks expressed lesser distress calls when exposed to a novel food. Unlike C21 chicks, C30 chicks expressed no preference for energetic food.

Conclusion/Significance

Our findings suggest that moderate heat challenge triggers maternal effects and modulate the developmental trajectory of offspring in a way that may be adaptive. This suggests that the impact of heat challenges on captive or wild populations might have a cross-generation effect.

Prenatal chemosensory learning by the predatory mite Neoseiulus californicus

Background

Prenatal or embryonic learning, behavioral change following experience made prior to birth, may have significant consequences for postnatal foraging behavior in a wide variety of animals, including mammals, birds, fish, amphibians, and molluscs. However, prenatal learning has not been previously shown in arthropods such as insects, spiders and mites.

Methodology/Principal Findings

We examined prenatal chemosensory learning in the plant-inhabiting predatory mite Neoseiulus californicus. We exposed these predators in the embryonic stage to two flavors (vanillin or anisaldehyde) or no flavor (neutral) by feeding their mothers on spider mite prey enriched with these flavors or not enriched with any flavor (neutral). After the predators reached the protonymphal stage, we assessed their prey choice through residence and feeding preferences in experiments, in which they were offered spider mites matching the maternal diet (neutral, vanillin or anisaldehyde spider mites) and non-matching spider mites. Predator protonymphs preferentially resided in the vicinity of spider mites matching the maternal diet irrespective of the type of maternal diet and choice situation. Across treatments, the protonymphs preferentially fed on spider mites matching the maternal diet. Prey and predator sizes did not differ among neutral, vanillin and anisaldehyde treatments, excluding the hypothesis that size-assortative predation influenced the outcome of the experiments.

Conclusions/Significance

Our study reports the first example of prenatal learning in arthropods.

Prenatal and early sucking influences on dietary preference in newborn, weaning, and young adult cats

Early experiences are of potential importance in shaping long-term behavior. This study examined the relative influence of prenatal and/or early postnatal experience of chemosensory stimuli on subsequent olfactory and dietary preferences of cats as newborns, at 9-10 weeks, and at 6 months. Cats were exposed to vanillin or 4-ethylguaiacol via their mother's diet either prenatally, postnatally, perinatally (prenatal and postnatal), or experienced no exposure to the stimuli (control). Newborns were given a two-choice olfactory test between the familiar "odor" and no odor; 9-10 week olds were tested for their preference between two food treats, one flavored with the familiar stimulus and the other unflavored; at 6 months, cats were given a choice of two bowls of food, one flavored with the familiar stimulus and the other unflavored. At all ages, cats preferred the familiar, and avoided the unfamiliar, stimulus. Perinatal exposure exerted the strongest influence on preference. Prenatal exposure influenced preference at all ages and postnatal exposure exerted a stronger effect as the cat aged. We conclude that long-term chemosensory and dietary preferences of cats are influenced by prenatal and early (nursing) postnatal experience, supporting a natural and biologically relevant mechanism for the safe transmission of diet from mother to young.

The developmental stage of chicken embryos modulates the impact of in ovo olfactory stimulation on food preferences

Like mammals, bird embryos are capable of chemosensory learning, but the ontogeny of their feeding preferences has not been examined. We tested if the timing of stimulation in chicken embryos modulates the impact of in ovo olfactory stimulation on later food preferences. We exposed chicken embryos to an olfactory stimulus for a 4-day period in the middle or toward the end of the incubation period. The chicks were tested for their preference between foods with and without the olfactory stimulus in 3-min choice tests and on a 24-h time scale. Regardless of the type of food (familiar or novel) or the duration of the test, the control chicks not exposed to the olfactory stimulus consistently showed significant preferences for non-odorized foods. Chicks that were exposed in ovo to the olfactory stimulus did not show a preference for odorized or non-odorized foods. Only those chicks that were exposed to the olfactory stimulus toward the end of the incubation period differed from the controls and incorporated a higher proportion of odorized food into their diets on a 24-h time scale. This result indicates that olfactory stimulation at the end of embryonic development has a stronger impact on later feeding preferences. Our findings contribute to the growing pool of recent data appreciating the impact of olfactory signals on behavior regulation in avian species.

Biased embryos: Prenatal experience alters the postnatal malleability of auditory preferences in bobwhite quail

Many precocial birds show a robust preference for the maternal call of their own species before and after hatching. This differential responsiveness to species-specific auditory stimuli by embryos and neonates has been the subject of study for more than four decades, but much remains unknown about the dynamics of this ability. Gottlieb [Gottlieb [1971]. Development of species identification in birds: An enquiry into the prenatal determinants of perception. Chicago/London: University of Chicago Press.] demonstrated that prenatal exposure to embryonic vocalizations serves to canalize the formation of species-specific preferences in ducklings. Apart from this, little is known about the features of the developmental system that serve to canalize such species-typical preferences, on the one hand, and generate novel behavioral phenotypes, on the other. In the current study, we show that briefly exposing bobwhite quail embryos to a heterospecific Japanese quail (JQ) maternal call significantly enhanced their acquisition of a preference for that call when chicks were provided with subsequent postnatal exposure to the same call. This was true whether postnatal exposure involved playback of the maternal call contingent upon chick contact vocalizations or yoked, non-contingent exposure to the call. Chicks that received both passive prenatal and contingent postnatal exposure to the JQ maternal call redirected their species-typical auditory preference, showing a significant preference for JQ call over the call of their own species. In contrast, chicks receiving only prenatal or only postnatal exposure to the JQ call did not show this redirection of their auditory preference. Our results indicate that prenatal sensory stimulation can significantly bias postnatal responsiveness to social stimuli, thereby altering the course of early learning and memory.