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A wide range of vertebrate species has been proved to be capable, following passive disorientation, to reorient into enclosures of different shapes using the metrical distribution of surfaces as surfaces and the geometric sense of left and right. Two procedures can be used to get a subject to loose its orientation: The subject itself can be rotated with the eyes closed or in the dark (viewer-movement procedure) or the external enclosure can be rotated while the subject stays still in a fixed position with the eyes closed or in the dark (i.e., without the possibility to notice any change outside; space-movement procedure). Although the 2 procedures are equivalent in that both cause a change in the spatial relationships between the viewer and the external layout, it has been suggested on the basis of research in human infants that they may involve the use of different frames of reference to reestablish one's bearing and relocate the target. However, no comparison between viewer- and space-movement procedures has been carried out in nonhuman species. Here, the authors show that newborn domestic chicks (Galluss gallus) can reorient effectively irrespective of the specific disorienting procedure applied. The results are discussed in comparative and developmental perspectives. Keywords: geometric module, spatial reorientation, viewer versus space movement, precocial versus altricial, chick DOI: 10.1037/a0017013

Spatial reorientation in a rectangular array of four landmarks located in the center of a circular enclosure was investigated in domestic chicks (Gallus gallus). One of the landmark possessed unique visual features, indicating the location of a food reward. After training, chicks were tested (a) with the same array as during the training; (b) with four identical landmarks of the type previously nonrewarded, of the type previously rewarded, or of a new type; (c) after having transformed one of the landmarks located at the geometric incorrect location into the type of landmark previously rewarded; or (d) with a fifth landmark of the rewarded type at a new location. Chicks encoded information provided by local featural cues but not the geometric information provided by the shape of the array. Moreover, when trained in a rectangular array of identical landmarks chicks failed to reorient. In a second series of experiments, the array was located in correspondence to the corners of a rectangular enclosure. This time chicks successfully learned to locate the reward using geometric information. However, when the rectangular array was located in the center of a larger rectangular enclosure, chicks failed to reorient, indicating that the geometric information given by the macroscopic layout of arena surfaces was not used to specify different locations. These results suggest that chicks reorient on the basis of a local representation of single landmarks and that encoding of the global aspects of geometry only occurs with respect to the large, extended surfaces of an enclosure. Keywords: landmark's array, geometric module, piloting, spatial orientation DOI: 10.1037/a0019145

The delayed-response problem is used to investigate the temporal characteristics of the ability of animals to represent and remember objects that have disappeared. The findings reveal that domestic chicks have striking abilities to remember the location of biologically attractive objects but outperform most mammals, including primates.

A study was conducted which monitored white-tailed ptarmigan, Lagopus leucurus, hen's food calls, a vocalizing and tidbitting display, to determine whether the chicks learned about important food resources from hen food calls. Results suggested that white-tailed ptarmigan hen's food calls might function to enhance survival of juvenile ptarmigan.

The temporal development and sensory basis of social discrimination by young chicks was investigated by conducting a series of experiments. It was concluded that the rapid development of individual discrimination by chicks was more influenced by the social partners' visual phenotype and not by the familiarization of smell and sedation.

Changes in intraspecific aggression among colonies of Argentine ants, Linepithema humile, in various discrimination contexts are examined. Results reveal that aggression occurred at higher rates when either nestmates or familiar territory indicated nest proximity, but not when social context is absent, thereby providing additional support for the optimal acceptance threshold model.

Byline: O. O. Litvin (1), K. V. Anokhin (1) Abstract: According to current concepts, memory can be disrupted by administration of protein synthesis inhibitors over a relatively short time period before and after learning. However, data have been obtained indicating that protein synthesis inhibitors can induce amnesia when given long after learning if administration is performed in reminder conditions, i.e., when the animal is presented with one of the environmental components which previously formed the learning situation. The aim of the present work was to confirm the possibility of inducing memory disruption in chicks at late post--learning stages by administering the protein synthesis inhibitor cycloheximide in association with a reminder procedure. Day--old chicks were trained to perform a standard passive avoidance task. Chicks were given cycloheximide (20 ug, intracerebrally) 5 min before the reminder procedure, which was performed 2, 24, or 48 h after training. Testing was conducted 0.5, 1, 3, 24, and 48 h after the reminder. Administration of cycloheximide in association with the reminder procedure induced the development of temporary amnesia, whose duration gradually decreased as the interval between training and reminding increased. These data led to the hypothesis that a memory reactivated by a reminder undergoes a process of reorganization and reconsolidation, which depends on the synthesis of new proteins. The quenching of the ability of protein synthesis inhibition during the reminder to disrupt memory demonstrates the existence of a gradual process resulting in consolidation of memory between 2 and 48 h of learning. Author Affiliation: (1) P. K. Anokhin Institute of Normal Physiology, Russian Academy of Medical Sciences, Moscow Article History: Registration Date: 16/10/2004

Dustbathing in featherless and feathered chicks was examined, and dustbathing was found to increase with time, with a compensatory adjustment, in both featherless and feathered chicks. It is suggested that the amount of dustbathing may be controlled by the cooperative action of a deprivation or timer mechanism and a counter mechanism. Lorenz's psycohydraulic model may be valid for other comfort behaviors as well as for dustbathing in fowl.

Domestic chicks were tested with a task involving an imprinting object. It was proposed that the chicks would search behind whichever hiding site the object was moving towards before occlusion.A sensitive period of learning about occlusion events leading to qualitative changes in the strategy for locating concealed objects, was also predicted.It is concluded that orientation towards the concealed object is based on previous spatial location alone.

Evidence suggests that odorants are important for forming attachments by domestic chicks but there is little evidence that nestlings remember odorants presented soon after they are hatched. A new study investigates whether early exposure to nonaversive odorants alters a chick's responses to natural odours, such as food, feathers and faeces of adult chicken. The study concludes that chicks learn about their olfactory environment during the latter part of incubation and in the early posthatching period.

Domestic chicks, Gallus gallus domesticus, able to traverse a T maze rapidly at two days old maintain closer social proximity than chicks who traverse the T maze slowly, irrespective of the time of day at which observations are made. Chicks identified as high performers in the T maze had a nonsignificant tendency to leave the start box of the runway sooner than low performing chicks. Each group of chicks showed similar levels of resting, ambulation, drinking, feeding, preening and pecking at the environment at five days old. This indicates that the contrasting behaviour shown in the T maze at two days old does not reflect underlying differences in general ability levels or in locomotor skills.

The warning signals of toxic insects often combine bright coloration with sounds or odours. Pyrazine is a common insect warning odour and can elicit avoidance in domestic chicks, Gallus gallus domesticus. The link between colour and odour found in experiments with pyrazine in domestic chicks was investigated. It is suggested that the novelty of the pyrazine is more responsible for eliciting a color bias rather than aspects of the odour.

Experiments conducted on day-old chicks showed that they can learn to avoid an aversive stimulus by observing responses from other chicks. However, results showed unclear evidences in the use of sensory cues or types of behavior by chicks to maintain avoidance. The experiments involved allowing a chick to peck at a bead coated with the bitter-tasting methylanthranilate, while another chick was allowed to observe the behavior of the actor chick.

Neural and behavioural analyses have shown that the formation of filial preferences in young, precocial birds involves at least two separate processes. One process is an emerging predisposition to approach stimuli with the characteristics of the natural mother. The other (learning) process of filial imprinting results in chicks preferentially approaching a stimulus to which they have been exposed and involves forming links between the components of the exposed stimulus. The neural substrate for the predisposition is different from that underlying imprinting, and different regions of the chick brain are involved in distinct aspects of learning about imprinting stimuli.

Recent signaling resolution models of parent-offspring conflict have provided an important framework for theoretical and empirical studies of communication and parental care. According to these models, signaling of need is stabilized by its cost. However, our computer simulations of the evolutionary dynamics of chick begging and parental investment show that in Godfray's model the signaling equilibrium is evolutionarily unstable: populations that start at the signaling equilibrium quickly depart from it. Furthermore, the signaling and nonsignaling equilibria are linked by a continuum of equilibria where chicks above a certain condition do not signal and we show that, contrary to intuition, fitness increases monotonically as the proportion of young that signal decreases. This result forces us to reconsider much of the current literature on signaling of need and highlights the need to investigate the evolutionary stability of signaling equilibria based on the handicap principle.

American avocets appear to recognize their young, with chick recognition becoming more developed as chicks grow older. This was gleaned from the results of a chick-exchange experiment designed to determine whether chick recognition exists in the avocets and its timing during chick development. Results also showed that adults show no aggression toward their young and that some discrimination may exist in the first week of the chick's life, as evidenced by the greater frequency of acceptance behavior in control trials than in fostering trials.

The hypothesis that feather pecking and foraging behavior are inversely related in laying hen chicks was investigated. Findings showed that both the quality and presence of the foraging materials had a substantial impact on foraging behavior and a substantial but opposite impact on feather pecking. Focal animal observations revealed that the chicks had different kinds of foraging behavior at polystyrene blocks and beads. Feather pecking may therefore be regarded as redirected foraging behavior.

Halupka and Halupka point out errors in sampling and data interpretation in the study of alarm calling by parents and the reaction of nestlings in Acrocephalus melanopogon or moustached warbler. Sampling error should not be a cause for concern, because the error about which they are concerned is one of analysis. Reactions to Halupka and Halupka are presented, and the issues that they raise are clarified.

A study was conducted on 42 groups of 30 laying hen chicks to determine the effects of feather pecking on foraging and dustbathing. Results show that chicks who had earlier access to sand as a dustbathing substrate exhibit lower feather pecking rates and that feather pecking is influenced by foraging activity. Results also reveal that feather pecking is minimized in housing conditions conducive to foraging.

A study of the response of domestic chicks to the aversant methyl anthranilate concludes that a discriminative stimulus can influence avian learning. The study seeks to discover whether chicks use odour to mediate visual signals in passive-avoidance learning and to evaluate whether odourless denatonium benzoate can be used as an alternative enforcer. Experiments show that odour can mediate avian food choice and that denatonium benzoate is a preferable alternative for avoidance learning experiments.

Many prey species use warning colours to protect themselves from predators, with some also emitting a distinctive olfactant when attacked. A study of domestic chicks to determine whether warning odours are as effective in deterring prey as warning colours shows that odours can stimulate taste-avoidance learning in birds. The research, using almond and vanilla odours to act as taste-avoidance cues, also shows that, in some circumstances, odour cues can take precedence over visual ones.

Pyrazine odors enhance the neophobic response of naive domestic chicks, Gallus gallus domesticus, towards prey with novel appearances. The behavior of chicks is observed by presenting them with food or water that is either familiar or colored with food dye. The odors considered are almond oil, 2-methoxy-3-sec-butyl pyrazine, 2-methoxy-3-isobutyl pyrazine, vanilla oil and thiazole. Pyrazines and almond odor enhance the latency of the chicks' food or water consumption but only when the food or water has a novel appearance. No significant effect of vanilla odor and thiazole is observed.

The response of pen-raised, six-day old northern bobwhite to red imported fire ants was studied in an experiment in 1993. The animal's behavior in a 30 square meter area where fire ants had been removed and in a similarly- sized area where fire ants are abundant was observed. The activities of the animal were classified as response to fire ants, moving, inactivity, sleeping, and food-pecking. Time spent at responding directly to the ants affected time allotted for daily activities such as moving, sleeping, and food-pecking. Ant activity and chick age affect time alloted to activities.

Difficulties in showing targetted searching behavior in chicks using mealworms as targets in a double screen test may be the result of the chick's fear response to the unusual environment, and not a sign that the chick is incapable of conceptualizing the worm. A similar double screen study using a 'friend,' in this case an imprinted red ball, suggests that chicks are able to exhibit searching behavior. The same study found that in the presence of a cage mate, chicks were more likely to search out the mealworm, likely due to less fear amongst the chicks than in previous studies.

Experiments on perceptual and motivational aspects of detour behavior in young chicks reveal that the time needed to develop itineraries to pass around the barrier and reach the goal decreases with decreased visibility and increase in goal distance. Vertical-bar barriers take longer time to negotiate than horizontal-bar barriers as they are mistaken for neutral obstacles. Visual interaction between the cagemates which is used as goals makes the task easier. Most detour problems arise because of chicks' inability to perceive the barred character of obstacles.

The idea that sensitivity to self-produced motion could lie at the foundations of the clear-cut divide that the brain operates between the two basic domains of inanimate and animate objects dates back to Aristotle. Sensitivity to self-propelled objects is apparent in human infants from around the fifth month of age, which leaves undetermined whether it is acquired by experience with animate objects or whether it is innately predisposed in the brain. Here, we report that newly hatched, visually naive domestic chicks presented with objects exhibiting motion either self-produced or caused by physical contact prefer to associate with self-propelled objects. This finding supports the idea of an evolutionarily ancient, predisposed neural mechanism in the vertebrate brain for the detection of animacy. animated object | self-propelled motion | filial imprinting | predisposition doi/10.1073/pnas.0908792107

Anexperiment on filial preferences in domestic chicks shows that such behavior involves learning and predisposition. The predisposition becomes evident with agrowing preference for a rotating, stuffed adult fowl over arotating red box. The experiment reveal that preferences remained unchanged over time when chicksare trained with the red box. Such findings imply that the mechanism fundamental to learning could be separated from the mechanism underlying the predisposition.

When given a choice of test male chicks, Gallus gallus domesticus L., using only their left eye chose to associate with the model with which they lived rather than moderate or large transformations of it. When choosing between a familiar model and a small transformation (45 [degrees] rotation of a bar on the face of a spherical model) or between a cagemate and a strange chick (from the same batch as those with which the chick lived), left-eyed chicks chose the strange model or chick. Males using both eyes behaved like left-eyed males, suggesting that the right hemisphere here controls normal behaviour. Right-eyed males chose at random, except when transformations were large; they then chose the familiar model. Female chicks under all conditions chose the familiar model, but when given a choice between familiar and strange chicks right-eyed females, like right-eyed males, failed to choose. Lateralization is thus not absent in females, but is sometimes masked. These findings and earlier evidence using very different stimuli suggest that the visual systems fed by the left eye are specialized to respond to small changes in any of a variety of stimulus properties.

Chicks tested in the open field immediately after being separated from their companions displayed fewer pecking responses, more distress calls, and less locomotion in comparison to chicks tested 4 hours after separation. Duration of rearing (number of days of group-housing) significantly affected only the distress calls of chicks.

Chick reactions are not the proximate cue for parental alarm calls, as the proximate hypothesis is supported only by correlational and indirect evidence. Only indirect evidence is provided that alarm calls may be directed towards chicks through the comparison of the presence or absence of parent alarm calls to various predator types and chick responses. It is proposed that the cue on which parents base their decision to increase the probability of alarm calling in the later nestling stage is when adaptive antipredator chick responses begin.

The warning signals of toxic insects often combine pyrazine odors with conspicuous colorations, such as red or yellow. An investigation of these warning signals in prey choice experiments with birds shows that pyrazine interacts with red and yellow to trigger strong aversions to these typical aposematic colors that are not shown in the absence of the odor. Pyrazine is not inherently aversive and does not produce aversion when combined with a less conspicuous color. These provide the first proof that the purpose of multicomponent signals lies in the psychological responses produced by the interaction of different sensory components.

Several field experiments are conducted to explain the impact of different levels of forb cover in brood habitat on the mass gain and feather growth of the human-imprinted sage-grouse chicks. An increase in the forb cover is shown to lead to an equivalent increase in the chick survival and productivity of the grouse.

The results of experiments conducted to study the ability of domestic fowl chicks (Gallus gallus domesticus) to recognize social partners are presented.

Impact of biparental care on the begging-for-food behavior of chicks and zibra finches is examined.

Impact of palatability of prey on the memory and prey defense learning is discussed. Gallus gallus domesticus (chicks) is used as simulation predators to study the same.

The early feather pecking that is a form of social exploration and the lateralization of functions that can be influenced by light exposure late in embryonic development is proposed. The effects of prenatal light exposure on early posthatching feather-pecking behavior in domestic chicks is investigated.

A series of experiments were conducted to investigate the role of this voluntary 'out-of-sight' behaviour on the development of spatial memory in young chicks. The findings suggest that active experience of occlusion around the eleventh day improved egocentric orientation towards an out-of-sight goal, supporting the hypothesis that enrichment-induced behavioural changes are dependent on the interaction with objects.

Begging behavior in black-headed grill chicks is experimented by injecting androgen in the first laid egg. This egg hatched and body grew faster and the chicks were more persistent in begging for food.

The aggregated attacks of Protocalliphora within broods of nestling blue tits are examined. The tasty chick hypothesis of potential aggregation of ectoparasite attacks on the smallest chicks in a brood is discussed.

The article describes a study which examined lateralization and the effect of visual experience on social recognition and approach in chicks. Study results indicate that visual experience of a social group is necessary before chicks using their right eye will pay attention to cues distinguishing one chick from another.

This study examines whether it is possible to improve the welfare of chickens by exploiting their olfactory attachments. Study results confirm that that olfactory memories exist in domestic chicks and supported the hypothesis that familar odorants can be reassuring situations that are unfamiliar otherwise.

Chicks learned to find food hidden under sawdust by ground-scratching in the central position of the floor of a closed arena. When tested in an arena of identical shape but a larger area, chicks searched at 2 different locations, one corresponding to the correct distance (i.e., center) in the smaller (training) arena and the other to the actual center of the test arena. When tested in an arena of the same shape but a smaller area, chicks searched in the center of it. These results suggest that chicks are able to encode information on the absolute and relative distance of the food from the walls of the arena. After training in the presence of a landmark located at the center of the arena, animals searched at the center even after the removal of the landmark. Marked changes in the height of the walls of the arena produced some displacement in searching behavior, suggesting that chicks used the angular size of the walls to estimate distances.

The present study examined whether visually evoked fear of depth could reinforce a particular response of animals, i.e., to special maze learning. The maze was composed of four units of Y-shaped alley. In this maze, the visual pitfalls were set behind corners of the alley in place of a physical barrier. The experiments showed that eight of 13 male chicks could achieve the initial learning and that three successful ones could also achieve reversal learning. The results suggest that the visually evoked fear of depth provided by motion parallax can act as a reinforcer.

Neonatal chicks that observe a demonstration consisting of an angular stimulus (arrow) 'pecking' at a distinctive food-like object will themselves peck preferentially at matching objects. The phenomenon appears to involve a transfer of control over the release of pecking by observer chicks. The pecking arrow enhances the ability of pecked objects to elicit directed responses from chicks. Varying the presence and spatial location of red and green objects in the display to chicks revealed: (a) similar enhanced responding to stimuli matching in colour the objects in the display that were attached to the pecking arrow, to the floor beneath the arrow, or both locations; (b) greater enhancement of responding to a stimulus colour appearing on the arrow during both up and down strokes; and (c) that, opposite to the predictions from a Pavlovian conditioning analysis, enhancement of responding to stimuli of one colour increased as a function of the presence and number of different coloured stimuli located in the display but displaced from the arrow. Des poussins nouveau-nes qui observent une demonstration consistant en un stimulus angulaire (fleche) 'picorant' un object distinct ressemblant a de la nourriture, picoreront eux-memes preferentiellement des objets semblables. Le phenomene semble impliquer un transfert du controle, par les poussins observateurs, sur le relachement de l'acte de picorer. La fleche picorante augmente la capacite de l'objet picore a eliciter des reponses dirigees de la part des poussins. La variation de la presence er de la localisation spatiale d'objets rouges et verts dans la presentation aux poussins a revele: (a) une reponse semblable plus forte a des stimuli dont la couleur etait la meme que ceux presentes et que etaient attaches la fleche picorante, au plancher au-dessous de la fleche ou aux deux endroits; (b) une augmentation encore plus grande de la reponse a un stimulus colore apparaissant sur la fleche pendant les coups hauts et bas; et (c) contrairement aux predictions tirees de l'analyse du conditionnement pavlovien, l'ampleur de la reponse aux stimuli d'une couleur augmentait en fonction de la presence et du nombre de stimuli de differentes couleurs situes dans le presentoir mais deplaces de la fleche.