An eclectic alphabet of chicken facts with a difference. Compiler: Andy Cawthray
A chicken’s eyes are positioned on the side of the head, which means it has good, almost all-round, sight, making it very efficient at spotting potential predators. Its vision is not completely allaround, however, as there is a blind spot toward the back of the head, but, if you consider full spherical vision is 360 degrees, then a chicken can see forwards with both eyes (binocular vision) for approximately 26 degrees, and the left and right eyes can operate in a monocular fashion to account for a further 300 degrees leaving only 34 degrees of blind spot and providing a total field of vision of 326 degrees; this is pretty good when compared to the human at 180 degrees, and it makes it pretty difficult for you if you are trying to catch them unawares. In fact eyesight is so important to chickens that the eyes together weigh almost as much as the brain
Chickens have the capacity to remember. This is not just a case of spatial memory, or remembering where the best foraging spots are, but is also the ability to recognise other individuals within a flock. Chickens have been shown to be able to recognize up to at least 96 other individuals within a flock.
Chickens have a hearing range slightly narrower than that of humans. It falls within 15Hz10,000Hz, with their most sensitive range being between 1,000-4,000Hz. Their main vocalizations, of which there are around twenty, tend to fall in this spectrum, and run from around 500-6,000Hz. Slight differences in pitch, tone, and rhythm enable recognition of individuals (or imposters), even if the bird calling cannot be seen. Chicks will learn this at a very early age, ensuring they always respond to the right mother’s call.
A chicken’s sense of smell is not particularly well developed. However, they are capable of responding to certain scents. Their olfactory receptors are
found in the upper jaw just beneath the nostrils.
A chicken’s sense of touch primarily relies upon the beak and the pads of the feet, both of which are essential in finding and consuming food. The receptors work by responding to pressure changes, and are very sensitive. Chickens are also able to detect vibrations using receptors in their feet, legs and skin. This sense enables them to be able to detect movement when light is poor or vision is obstructed. When such movement is identified the bird will become alert and may emit a warning call.
The skin also provides for a level of sensitivity for the chicken. Warm and cold temperatures are monitored via receptors within the skin enabling the bird to respond according. Specialized nerve endings in the skin of the chicken known as nociceptors sense pain and unpleasant stimulation which all serve to protect the bird through provoking a reaction in much the same as a human would recoil from a flame or excessively hot water.
This term is often used to imply an inferior intelligence, and the age old joke questioning the motives the chicken crossing the road also seems to add to the perception that they have little intelligence. Granted, there are some individuals and breeds whose behaviour may seem lacking in common sense. However, many of the cognitive abilities of chickens are in fact comparable with primates. This is reflected in the fact that the brain of a chicken is around 9 times bigger than the brain of a reptile of a similar size.
Given the levels of domestic husbandry chickens have undergone, coupled with their ability to evolve new survival strategies to cope with the changing environmental pressures imposed on them through domesticity, they are not an unintelligent species.
This is the scientific term used to explain the physical differences in the appearance of male and female chickens of the same breed. It is the way keepers can tell the sexes apart. It is also a visual sense used to a degree by chickens, and, consequently, a particularly henny-feathered male within a mixed sex flock may inadvertently find himself the focus of another male bird’s amorous intensions.
Good all round vision
The amazing nasal construct of an Owlbird
TOP: Receptors in the skin will warn of the cold ABOVE RIGHT: The beak is essential for the sense of touch LEFT: Not so bird brained after all...