- Being a social bird from the open forest, the hen has developed a wide range of sounds for communication.
- Studies have classified 12 chick calls and 22 calls by adults. These range from clucks, cackles, chirps and cries to keep in contact with mates.
- Calls heard most often and recognised by humans are food calls, predator alarms, pre- and post-laying calls and roosters crowing. Others are more specific which humans find hard to identify.
- Another classification describes:
- Vocal calls related to fear and predators
- Physiological calls to do with brooding, feeding, contact and pleasure
- Signals expressing pain, frustration, fighting and crowing.
- There's a well-recognised daily pattern of crowing near dawn followed by feeding calls, egg-laying calls and finally roosting calls. Chicken distress calls immediately get the attention of their broody mother, and the regular "cluck -cluck" is a reassuring call from the mother to the chicks.
- Large groups of hens can create very high noise levels. They are around 72-87dB at normal times, 73-100 dB at feeding and 75-85 dB during egg laying.
- A study showed that laying hens were affected by levels above 83dB, while higher levels induced fear and panic.
- When hens can see each other, they communicate by body postures e.g. head up or down, tail up or down, feathers spread or not.
- The tail is especially important and studies of feral birds showed that they stood upright with tail erect with wings diamond-pointed almost vertically down. This is called "wing-down alert".
- Body postures are particularly important to dominant males to send messages to his harem and possible competitors for his job.
- Studies have shown that birds recognise each other using a combination of comb, head and wattle. Single elements were more difficult for hens to recognise, but the comb was the simplest.
- Colour changes to plumage were noticed, with intense colours more easily seen than pale colours.
- Only abrupt and very dramatic changes cause a hen to be treated as a stranger.
Pecking and peck order
- Pecking is very much a species-specific behaviour of hens. They peck to:
- Release them from the shell.
- To find feed and eat it.
- To drink.
- To obtain space.
- To get recognition from others.
- To mate.
- And many more highly sophisticated actions.
- Hens maintain a personal space around their heads and keep a distance from each other by holding their heads at an angle and maintaining a specific body orientation.
- If a direct head-to-head stance is taken, then pecking will ensue.
- The main purpose of pecking is in eating and it's a very precisely tuned movement of the head and neck, the feed being first picked up and then in a further movement of the head, it is swallowed.
- Incorrect timing of these movements would severely jar the neck. The bird's binocular vision is important in judging the distance to peck with the eye membranes closed at the moment of impact.
- The relationship of body stance and head position is important during pecking attacks. These include threats in which one bird lifts its head above the level of the other bird's head, then pecks the comb, head, neck or nape, wattles and then chases the subordinate away.
- If two birds face up to each other to fight, they peck, kick with their feet and slash with their spurs. Crouching or running away shows submission. These fights are not common outdoors but they increase as stocking rates increase towards 400 square cm/bird.
- In free-living birds, pecking is greatly reduced when males are present, as presumably the peck order is more clearly established.
- Pecking is often greatest in adolescent hens and observations have shown the incidence to be 30-50% greater on floors than in cages. Pecking was 70% higher when males were absent.
- Practical suggestions to help stabilise a peck order quickly to avoid any negative impact on egg production are:
- Form new groups of hens by mixing them before they start laying
- Do not revolve birds around groups - leave them settled
- Provide plenty of feed and watering points and plenty of floor space when the flock is settling.
- If two groups have to be mixed, put equal numbers of each subgroup together.
- Make sure males have been together in a group before mixing with the hens
- Putting a male among hens will reduce pecking.
- Much of the pecking in caged birds occurs during feeding bouts, and depends on the feeder space and number of birds in the cage.
- Hens love to dust bath, and it is clearly an innate behaviour.
- Dust bathing behaviour actions are even seen by birds bred with no feathers.
- We assume that hens dust bathe to control parasites and align their feathers. Normally free-living hens spend their time dispersed except when it comes to dust bathing, which they seem to love to do communally.
- Dust bathing is also thought to be a type of vacuum activity seen in birds that have been released from cages after at least 100 hours without a bath, or in birds with previous experience of the practice.
- Dust bathing usually starts with pecking into an area of dry dust, squatting in it, turning and raising dust into the feathers and then shaking it out again.
Preening and feather care
- In preening, the hen raises the feathers and cleans them by stroking and nibbling them with the beak.
- Grooming in the hen is described as actions related to maintaining body surface including preening with the beak, scratching with the foot, dust bathing and oiling.
- Oil is produced from the urophygial gland near the tail and birds use their beak to spread oil from it over their feathers.
- Hens preen or groom to remove lice, and females are more efficient groomers than males.
- Hens also spend more time grooming and using their oil gland than cocks.
Other comfort behaviours
- Bill wiping is seen after birds have been eating wet mash.
- The bird wipes one side of the beak on the ground, and in one continuous movement wipes the other side.
- Unilateral stretching of the leg and wing is also common comfort behaviour along with wing flapping while standing still.
Roosting or perching
- The feet of a bird are designed for holding on to branches while resting and roosting.
- The wild jungle fowl roosts up off the ground in a communal roost in the centre of its territory.
- Wild birds will also perch at different levels.
- Depriving birds of these behaviours is one of the main concerns with modern poultry husbandry.