Enhanced prenatal auditory experience facilitates species-specific visual responsiveness in bobwhite quail chicks (Colinus virginianus)

Premature stimulation of a later developing sensory system is known to impact the functioning of earlier developing sensory systems. For example, exposure to premature (prenatal) visual experience results in a decline in species-typical auditory responsiveness in several precocial bird species. The present study examined the influence of experiential enhancement of an earlier developing sensory system on a later developing modality. Specifically, the influence of enhanced prenatal auditory stimulation on subsequent postnatal auditory and visual functioning of bobwhite quail (Colinus virginianus) chicks was assessed. Results indicate that birds receiving exposure to increased amounts of unaltered, species-typical embryonic vocalizations before hatching show species-typical auditory responsiveness at both 12 hr and 24 hr after hatching, but exhibit an accelerated pattern of species-typical visual responsiveness by 24 hr of age. These findings suggest that enhancement of an earlier developing sensory system can facilitate the development of a later developing sensory system and serve to demonstrate the dynamic nature of early perceptual organization.     

Early visual experience affects postnatal auditory responsiveness in bobwhite quail (Colinus virginianus)

Results from 6 experiments suggest perinatal visual experience interferes with postnatal auditory responsiveness in bobwhite quail (Colinus virginianus). Light- or dark-reared control chicks responded similarly to bobwhite maternal Calls A or B following hatching. Light-reared chicks that experienced 10 min/hr of Call A or B from hatching until testing preferred the familiar call at Days 2-4, but dark-reared chicks preferred the familiar call at all ages. Increased amounts of exposure to maternal calls during postnatal Days 1-2 led to auditory responsiveness deficits in light-reared chicks. Similarly, embryos exposed to 10 min/hr of prenatal visual cues required 48 hr of postnatal Call A or B exposure to demonstrate auditory discrimination. These findings highlight the linkages between developing auditory and visual systems during infancy.     

Intersensory redundancy facilitates prenatal perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) selectively recruits attention and facilitates perceptual learning in human infants. This comparative study examined whether intersensory redundancy also facilitates perceptual learning prenatally. The authors assessed quail (Colinus virginianus) embryos' ability to learn a maternal call when it was (a) unimodal, (b) concurrent but asynchronous with patterned light, or (c) redundant and synchronous with patterned light. Chicks' preference for the familiar over a novel maternal call was assessed 24 hr following hatching. Chicks receiving redundant, synchronous stimulation as embryos learned the call 4 times faster than those who received unimodal exposure. Chicks who received asynchronous bimodal stimulation showed no evidence of learning. These results provide the first evidence that embryos are sensitive to redundant, bimodal information and that it can facilitate learning during the prenatal period.     

Prenatal experience and postnatal perceptual preferences: evidence for attentional-bias in bobwhite quail embryos (Colinus virginianus)

Previous studies have indicated that concurrent multimodal sensory stimulation can interfere with prenatal perceptual learning. This study further examined this issue by exposing 3 groups of bobwhite quail embryos (Colinus virginianus) to (a) no supplemental stimulation, (b) a bobwhite maternal call, or (c) a maternal call paired with a pulsating light in the period prior to hatching. Experiments differed in terms of the types of stimuli presented during postnatal preference tests. Embryos receiving no supplemental stimulation showed no preference between stimulus events in all testing conditions. Embryos receiving exposure to the unimodal maternal call preferred the familiar call over an unfamiliar call regardless of the presence or absence of pulsating light during testing. Embryos exposed to the call-light compound preferred the familiar call only when it was paired with the light during testing. These results suggest that concurrent multimodal stimulation does not interfere with prenatal perceptual learning by overwhelming the young organism's limited attentional capacities. Rather, multimodal stimulation biases what information is attended to during exposure and subsequent testing.     

Species-specific auditory preference of bobwhite quail chicks (Colinus virginianus) is altered by social interaction with siblings

This study examined whether reinstating specific aspects of the normally occurring postnatal setting (ongoing social interaction with siblings during rearing and/or testing) would influence bobwhite quail chicks' attraction to their species-typical maternal call. Results revealed that incubator-reared chicks exhibit a strong preference for the species-typical bobwhite maternal call over a group of same-aged siblings in simultaneous choice tests at 24 hr and 48 hr after hatching, but only if the birds are kept in relative social isolation. No preference for the maternal call was found at 24 hr or at 48 hr if chicks were reared in a group of same-aged chicks from hatching and tested to the maternal call vs. siblings or the maternal call paired with a live adult bobwhite hen vs. siblings. These results raise doubts about the appropriateness of the usual methods of isolation rearing in the study of species-typical perceptual preferences and underscore the importance of considering features of the natural social context in the analysis of early perceptual and social behavior.     

Interactive and vicarious acquisition of auditory preferences in Northern bobwhite (Colinus virginianus) chicks

Studies examining the effects of stimulus contingency on filial imprinting have produced inconsistent findings. In the current study, day-old bobwhite chicks (Colinus virginianus) received individual 5-min sessions in which they were provided contingent, noncontingent, or vicarious exposure to a variant of a bobwhite maternal assembly call. Chicks given contingent exposure to the call showed a significant preference for the familiar call 24 hr following exposure and significantly greater preferences than chicks given noncontingent exposure. Chicks given vicarious exposure to recordings of another chick interacting with the maternal call showed significant deviations from chance responding; however, the direction of chick preference (toward the familiar or unfamiliar) depended on the particular call used. These results indicate that both direct and indirect (vicarious) exposure to stimulus contingency can enhance the acquisition of auditory preferences in precocial avian hatchlings. Precocial avian hatchlings thus likely play a more active role in directing their own perceptual and behavioral development than has typically been thought.     

Modification of prenatal auditory experience alters postnatal auditory preferences of bobwhite quail chicks

This study assessed the effects of altered prenatal auditory experience on bobwhite quail chicks' (Colinus virginianus) species-specific preference for the bobwhite maternal call. Results revealed that when the repetition rate of the embryonic vocalizations normally present in the prenatal environment was altered, the species-typical auditory preference of hatchlings for the maternal call was also altered. Specifically, embryos exposed to embryonic vocalizations with a faster repetition rate than normal subsequently preferred a bobwhite maternal call with a faster repetition rate over one with its normal repetition rate. Bobwhite embryos thus appear able to abstract features of their prenatal auditory environment to other auditory events in the postnatal period. This demonstration of prenatal perceptual learning is in keeping with other recent studies from behavioural embryology, which have also demonstrated that prenatal perceptual experience can influence later responses to species-typical stimulation.     

Modification of prenatal auditory experience alters postnatal auditory preferences of bobwhite quail chicks.

This study assessed the effects of altered prenatal auditory experience on bobwhite quail chicks' (Colinus virginianus) species-specific preference for the bobwhite maternal call. Results revealed that when the repetition rate of the embryonic vocalizations normally present in the prenatal environment was altered, the species-typical auditory preference of hatchlings for the maternal call was also altered. Specifically, embryos exposed to embryonic vocalizations with a faster repetition rate than normal subsequently preferred a bobwhite maternal call with a faster repetition rate over one with its normal repetition rate. Bobwhite embryos thus appear able to abstract features of their prenatal auditory environment to other auditory events in the postnatal period. This demonstration of prenatal perceptual learning is in keeping with other recent studies from behavioural embryology, which have also demonstrated that prenatal perceptual experience can influence later responses to species-typical stimulation.     

The effect of methyl parathion on susceptibility of bobwhite quail (Colinus virginianus) to domestic cat predation

Bobwhite quail (Colinus virginianus) that received either 0, 2, 4, or 8 mg/kg methyl parathion (O,O-dimethyl o-p-nitrophenyl phosphorothioate) treatment were investigated as to their susceptibility to predation by a cat (Felis domesticus) predator. Four hours after receiving methyl parathion (MP), physical activity levels were monitored in quail and included the number of seconds spent still, walking, running, or flying before and after a cat was introduced into an experimental arena. The cholinesterase (ChE) activity for each quail on experiment was determined. Quail that were captured exhibited significantly greater inhibition of brain ChE activity and spent significantly more time being still than noncaptured birds. Birds receiving MP at 8 mg/kg spent more seconds being still than those in other treatment groups and had ChE activity reduced to 42.8% of normal activity. There was a tendency for quail at increasing treatment levels to be more susceptible to capture by the cat predator. The neurological and behavioral effects of methyl parathion may have important ecological ramifications.     

Bobwhite quail (Colinus virginianus) hatchlings track the direction of human gaze

Gaze following allows individuals to detect the locus of attention of both conspecifics and other species. However, little is known about how this ability develops. We explored the emergence of bobwhite quail hatchlings’ ability to track human gaze by assessing their avoidance behavior in an open arena under five testing conditions: (1) a Direct Gaze condition, in which an experimenter looking down was positioned above one of two approach areas; (2) a Gaze Follow condition in which an experimenter, positioned equidistant between two approach areas, directed his/her gaze towards one of the areas; (3) a Masked Gaze Follow condition, in which the experimenter wore a mask during the Gaze Follow test; (4) a Deprived Face Experience condition, in which hatchlings were deprived of experience with human faces prior to the Gaze Follow test; and (5) a Control condition in which no experimenter was present during testing. Results revealed that hatchlings from the Direct Gaze condition preferred the non-gazed approach area at all ages tested. Hatchlings from the Gaze Follow condition preferred the non-gazed approach area at 48 and 72 h, but not at 24 h of age. In contrast, hatchlings from the Masked Gaze Follow, Deprived Face and Control conditions did not prefer either approach area at any age tested. These results indicate that experience with human faces plays a key role in the rapid emergence of gaze following behavior in bobwhite quail hatchlings.     

Fear responses of Bobwhite Quail (Colinus virginianus) to a model and a live Red-tailed Hawk (Buteo jamaicensis)

Zusammenfassung Furchtreaktionen gekäfigter, von Hand aufgezogener Baumwachteln (Colinus virginianus) wurden mit Hilfe eines handzahmen Bussards der Art Buteo jamaicensis und seiner lebensgroßen Flugattrappe qualitativ und quantitativ untersucht. Dabei beachteten wir Kontrollmaßnahmen, die andere Autoren in ähnlichen Untersuchungen bisher vernachlässigt hatten.Zweimal am Tage setzten wir zehn männliche und acht weibliche erwachsene Baumwachteln in einem 152.5 auf 183.0 cm weiten und innen 37.5 cm hohen Gehege aus und ließen die beiden Auslöser auf vorgeschriebener Bahn darüber hinwegfliegen. Nachdem jedes Versuchstier den einen oder den ändern der beiden Auslöser in einer Serie von Versuchen wahrgenommen und darauf angesprochen hatte, wurde in einer unmittelbar danach folgenden Versuchsreihe der noch unbekannte Auslöser geboten.Die Versuchsergebnisse wurden statistisch bearbeitet. Die Reaktionen der Baumwachteln waren dem lebenden Bussard gegenüber erheblich ausgeprägter als gegenüber der Attrappe, deren Auslösewert, verglichen mit dem des lebenden Bussards für die erste Spontanreaktion der Wachteln 95,3 % geringer war. Wiederholtes Darbieten eines Auslösers führte zur Abgewöhnung einer Reaktion (Habituation im Gegensatz zu Ermüdung). Die Auswirkung der Erfahrung mit dem einen Auslöser übertrug sich auf die Begegnung mit dem zweiten und wirkte sich als beschleunigtes Abgewöhnen der Furchtreaktion, nicht aber als deren vollständige Unterdrückung aus. Damit wird deutlich, daß die beiden Auslöser verschiedene Kombinationen von spezifischen Schlüsselreizen aufweisen, und im besonderen, daß die Schlüsselreize der Attrappe zur Auslösung des vollständigen artspezifischen Furchtverhaltens nicht zureichend sind.In der Diskussion der Befunde wird die biologische Bedeutung der Abgewöhnung hervorgehoben; ebenso wird auf die Ähnlichkeit der Abgewöhnung mit dem Vorgang der Auslöschung einer bedingten Reaktion hingewiesen.

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Research performed in fulfillment of the requirements of the course, Individual Studies in Animal Biology (BLY 630), under the direction of E. G. F. Sauer, Department of Biology.     

Amount of prenatal visual stimulation alters incubation times and postnatal preferences in leopard geckos (Eublepharis macularius)

The authors exposed gecko (Eublepharis macularius) embryos to patterned visual stimulation beginning at either 1 week or 2 weeks prior to hatching. Embryos exposed to the substantially augmented amount of prenatal visual stimulation hatched significantly earlier than the embryos either exposed to the moderately augmented prenatal visual stimulation or not exposed to any prenatal visual stimulation (p < .01). Hatchling mass was not affected. Embryos exposed to substantially augmented visual stimulation demonstrated a postnatal preference for patterned light in a simultaneous choice test at 24 hr of age (p < .01). Control embryos demonstrated a preference for normal light conditions (p < .01), whereas experimental embryos exposed to lesser amounts of prenatal visual stimulation did not show a preference for either stimulus. At 1 week of age, geckos in all conditions failed to exhibit a preference for either stimulus.     

Constitutional biases in early perceptual learning: III. Similarities and differences between artificially selected and imprinted color preferences in quail chicks (Coturnix coturnix japonica)

Color preferences and preference generalization were tested in naive and imprinted Japanese quail chicks drawn from the 20th generation of a genetic control line and two genetic lines that were bidirectionally selected for preferences between blue and red. Twelve hours of imprinting to blue or red on the first posthatch day resulted in large preference changes in the genetic controls, and these subjects exhibited no or only small additional changes from 3 more days of imprinting (for the total of 66 hr of exposure time). By contrast, 12 hr of imprinting of artificially selected subjects did not change or only marginally changed their genetically manipulated preferences, but 66 hr of imprinting changed them by magnitudes as large as or larger than those in genetic controls. Reciprocal imprinting partially mimicked the phenotypic effects of bidirectional selection. Differences between transfer and generalization of phenotypically similar but genetically and experimentally different preferences indicated dissimilar mediation of the implicit gene effects and learning effects.     

Genetic and experiential manipulation of fear-related behavior in Japanese quail chicks (Coturnix coturnix japonica)

We examined effects of environmental enrichment and regular handling on fear-related responses in chicks of Japanese quail (Coturnix coturnix japonica) selected over several generations for short or long tonic immobility (STI and LTI, respectively). STI chicks froze less, vocalized and walked sooner and more in an open field, emerged sooner from a hole-in-the-wall box, and showed shorter TI reactions than did chicks of the LTI line. Similarly, environmental enrichment reduced silence and inactivity in the open field, accelerated emergence, and attenuated TI. Regular handling promoted open-field vocalization and reduced the duration of TI but exerted no other significant effects. Principal component analysis showed that the responses in the 3 tests were not independent, which implies that they measured the same underlying factor. The genetic and experiential manipulation of stimulus-specific fears and of general fearfulness is discussed.     

Constitutional biases in early perceptual learning: I. Preferences between colors, patterns, and composite stimuli of colors and patterns in genetically manipulated and imprinted quail chicks (C. coturnix japonica)

Bidirectional genetic selection of quail for early color preferences, for eighteen generations, resulted in nearly perfect choices of blue over red in one and red over blue in the other selected line. It also enhanced the preference of a grated over a dotted black-and-white pattern. Color and pattern preferences in hybrids of selected and control lines fell back to about halfway between parental values. Choices between composite stimuli of colors and patterns indicated summation of the respective, genetically influenced preference values, with partial dominance of color over pattern effects. Exposure to colors modified color choices. Exposure to colored patterns likewise modified color choices, but it did not change, or only marginally changed, choices between patterns. The phenotypic expression of this selective learning, however, was influenced by the genetically manipulated preference values and preference combinations of colors and patterns in the stimuli with which postexposure performances were tested. Overall, the data highlighted the need for concepts that would discriminate between the developmental and the episodic expression of genetic influences and genotype--environment interactions in behavior.     

Divergent selection for duration of tonic immobility and social reinstatement behavior in Japanese quail (Coturnix coturnix japonica) chicks

Japanese quail (Coturnix coturnix japonica) were selected over 8 generations for long or short duration of tonic immobility (TI) weighted for independence from social reinstatement (SR) behavior (as measured in a treadmill) and for high or low levels of SR behavior weighted for independence from duration of TI. Divergent selection for long or short duration of TI and for high or low levels of SR behavior resulted in immediate and significant responses that continued throughout the 8 generations. There was no evidence of a plateau in the response to selection in any of the lines. SR responses did not vary in lines selected for duration of TI and vice versa. Selection for short duration of TI led to in an increase in the number of inductions required to induce TI. Selection for low levels of SR behavior led to a decrease in the tendency to move toward conspecifics but not to an increase in the tendency to move away from conspecifics.     

Role of telereceptive and interoceptive (taste) cues in ingestional neophobia in chicks (Gallus domesticus)

Experiment 1 investigated the influence of telereceptive (visual) and interoceptive (taste) cues on neophobia by measuring the intakes of clear water and novel solutions of red-colored water, clear 4.0% vinegar, or red-colored 4.0% vinegar in chicks (Gallus domesticus) on 5 test days. Neophobia was reliably greater the more numerous the novel stimuli in testing (i.e., red-colored vinegar) but was similar in magnitude for novel visual and novel taste cues alone. In Experiment 2 chicks received zero, one, or five preexposures to red-colored water or to clear 4.0% vinegar and were tested for neophobia to red-colored 4.0% vinegar. Intake of red vinegar reliably increased with the number of preexposures. However, preexposure to red-colored water facilitated intake of red vinegar more than preexposure to clear 4.0% vinegar did. These results suggest that the familiarity of telereceptive (visual) stimuli attenuates the demonstration of taste neophobia.