Some animals tend to give specific calls when they discover food or detect particular types of predators. Companions of those animals tend to respond with food searching behavior or adopt some appropriate escape responses and those response signals seem to denote objects in the environment. Per research mentioned below, it can be seen that male rooster (Gallus gallus) food calls to hens correspond to social responses and referential signalling.
Per Robert Grillo in 2014, "a hierarchal order is very important to the social lives of chickens. The head rooster protects the territory the group inhabits, as well as the chicks and hens in the group. Groups are composed of more dominant hens who remain close to the head rooster as well as more submissive hens and roosters who keep closer to the periphery. Roosters display a number of courting rituals to attract mates. Hens are attracted to roosters based on both their physical and behavioral characteristics. The pecking order, once established, maintains order and stability within the group."
Research shows that "under natural conditions, discovery of food by a male rooster in the presence of a hen reliably elicits the multimodal tidbitting display. Tidbitting is characterized as a repeated, rhythmic motion of the head and neck, including repeated picking up and dropping of the food item. This often entices one or more hens to approach the tidbitting male and food search near him, sometimes taking the food item directly from his mandibles. Hens prefer to mate with males that provide food and, in the presence of a hen, dominant males respond to a subordinate’s food calling and tidbitting display with overt aggression, often chasing him away from the food and then food calling themselves. On occasions, subordinate males alter the signal by producing only the visual component, suppressing the call. Experimental playbacks demonstrate that these unimodal displays still attract hens to the silently tidbitting male."
Per Carolynn L. Smith et.al. in 2009, this tidbitting helps in two ways.
"1. Referential signaling: Hens respond significantly more to a silently tidbitting male than to any other motion type which was revealed precisely by comparisons of food-searching duration through the predicted pattern of responses. The tidbitting display is sufficient to evoke foraging behavior and that responses to these movements have specificity similar to that previously demonstrated for food calls. Tidbitting movements therefore have all the characteristics of a functionally referential visual signal.
2. Social responses: For males, achieving close proximity to a hen is an important factor in mating success. Tidbitting can play an important role where hens spend more time standing close to the silent tidbitting male than they did during any other treatment during research. Subordinate males were able to tidbit as frequently as alphas when the subordinate male could display out of sight of the alpha. In flocks living under naturalistic conditions, researchers observed that subordinate males tidbit with silent food calling. This behavior created additional mating opportunities by attracting nearby hens, which approached and food searched near him."
The food calls of male fowl, Gallus gallus, are functionally referential and the acoustic component of a multimodal display. However, the specificity of the receiver’s response to the visual component (tidbitting) has never been tested. Here we provide the first detailed analysis of tidbitting, and test the hypothesis that these characteristic movements are functionally referential. These social responses suggest that the visual component of the display has the unique function of triggering assessment of signaler identity and quality as a potential mate.
Researchers also claim that the food call triggers other chickens to look for specific information whether or not they already know if food is present and to respond appropriately. Results from research by Christopher S Evans et.al. in 2007 show that chicken food calls stimulate retrieval of information about a class of external events and thus represent representational signalling in birds.
These results demonstrate that chicken food calls evoke selective retrieval of information about the discovery of food. When heard in a setting in which corn had not recently been found, they triggered characteristic searching behaviour. In contrast, the same signal heard minutes after ingesting a small quantity of food had no effect. Our interpretation is that under these conditions, the food calls provided no new information about the hens' immediate environment. We conclude that the cognitive processes engaged by these avian signals include nominal representations, which may prove to have properties in common with those that have been revealed in studies of associative learning. To our knowledge, this is the first demonstration of representational signalling in any non-primate species.
