Behavior Problems of Poultry

Aggression between flockmates characteristically involves one or more birds targeting one another with sharp, forceful pecks, typically to the head. Such aggression is common and necessary in the formation of social hierarchies. This type of aggression is typically settled within 24–48 hours and should lead to little, if any, injury.

Chickens can begin to show aggressive pecking as young as 2 weeks old. Turkeys generally begin to show aggression at approximately 3 months old. Ducks also show aggression, but little is known about this behavior in ducks.

Aggression becomes a problem when it leads to injury or becomes pervasive within a flock. When injury occurs, generally in the form of head and comb wounds, the afflicted bird should be removed and the wounds cleaned. Wounds should be treated with a tar-based salve or commercially available wound sprays.

A bloody wound often attracts other birds to peck at it. Death of the injured bird and cannibalism (pecking, tearing, and consuming skin, tissues, or organs) are the most severe outcomes of interbird aggression.

Cockfighting is thought to have been a principal factor driving the domestication of chickens. Genetic traits linked to aggression and fighting behavior persist in modern birds. The genetic propensity for aggression results in some highly aggressive individuals that might have to be removed from a flock.

Other interventions to prevent fighting include providing beak-related enrichment, such as foraging opportunities (eg, foraging blocks, bales of hay). If birds are engaging their beaks in foraging, they cannot simultaneously engage in aggressive pecking.

Installing perches also helps to prevent fighting, by giving birds that are being pecked a place to escape to.

Also see Common Management-Related Problems in Backyard Poultry.

Feather pecking is a distinct form of aggressive pecking that occurs in chickens, turkeys, and ducks. Feather pecking is closely related to feeding behavior and is directed at feathers.

There are two types of feather pecking: gentle and severe. In gentle feather pecking, birds mouth the feathers of other birds, causing feather fraying and damage. In severe feather picking, the feathers are grabbed and yanked out of another bird, resulting in pain, feather loss, and exposed skin that is susceptible to wounds and lesions.

Nutritional deficiencies, low temperature, bright lighting, and lack of substrate have all been identified as causes of feather pecking. Providing foraging opportunities and loose substrate can help minimize feather pecking. In commercial production, often beaks are trimmed to help decrease damage from feather pecking.

Panic (hysteria) afflicts all types of poultry—in particular, turkeys. Panic occurs when one or more birds are suddenly frightened and erupt into escape behavior. Each adjacent bird then erupts in turn, until most/all birds in a flock are involved.

In confinement, birds typically fly and/or run into walls when attempting to escape. Other birds then fly into them, leading to a pileup. Pileups result in mass crushing deaths, as well as death from hyperthermia in birds near the bottom of the pile.

Panic can occur in caged systems as well, with panic moving between cages.

Large flock sizes and barren environments are associated with panic.

Some management techniques can lessen the likelihood of panic:

• Providing a cue to the birds that something is about to happen, such as knocking on the door before entering a henhouse, helps to decrease surprise.

• Moving calmly and steadily around the birds also helps to lessen fear reactions.

• Providing enrichment and decreasing flock sizes, if possible, not only lessens the likelihood of panic but also decreases the effects if panic occurs.

Egg eating is a common problematic behavior ofhens of all poultry species. It typically begins when a hen encounters a broken egg. The shiny, leaking albumen invites exploration, and the hen develops a taste for eggs.

Although a hen might at first eat only broken eggs, she quickly learns to break the eggs open herself. Egg eating is also a socially learned behavior, so a single egg eater can lead to the problem of multiple egg eaters.

Egg eating is almost impossible to stop once it starts. Therefore, prevention of egg eating is key.

To prevent eggs from accidentally cracking and breaking, ample nesting spaces with soft substrates should be provided. Collecting eggs on a regular basis also decreases the likelihood of broken eggs. Cleaning up broken eggs as soon as they are found is also essential.

Any hen that becomes an egg eater should be identified as soon as possible and separated from the flock. The finding of dried egg white and yolk on the beak and feathers around the head indicates egg eating.

• Appleby MC, Mench JA, Hughes BO. Poultry Behaviour and Welfare. CABI; 2004.

• Mench JA, ed. Advances in Poultry Welfare. Woodhead Publishing; 2017.

• Nicol CJ. The Behavioural Biology of Chickens. CABI; 2015.