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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.

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.

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.

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.

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.

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.

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.

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.

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.