3. Mechanism

This post includes the following sections:
Redirected foraging behaviour
How does it develop?
Triggers and stress
Further reading

Redirected foraging behaviour

Junglefowl – ancestors of the modern chicken – spend more than 60% of their time foraging. This food-searching behaviour comprises scratching the ground and pecking to select edible particles. Modern laying hens still possess this instinctive urge to forage, which can already be seen in young chicks, which start to forage immediately after hatching. In the absence of good foraging material chicks redirect their pecking behaviour towards other available substrates; often the feather cover of conspecifics. Once focused to peck at feathers, this behaviour is very difficult to stop.
.

How does it develop?

In the absence of good foraging substrate, feather pecking can easily develop. When chicks are placed in the rearing system they immediately start to look for foraging material. When foraging material is not available or not suitable (e.g. birds are kept on paper or wire floor without substrate), they will redirect their foraging urge towards other materials, e.g. the feathers of conspecifics. Once developed during rearing, the behaviour will continue throughout their lives. Even when birds have been provided with litter at the beginning of the rearing period, the absence of suitable foraging material later in life may still lead to feather pecking.

Absence of good quality friable litter at any stage of the life cycle can trigger birds to start feather pecking, especially when this coincides with stressful events, such as changes in feed, bad climate, disease problems, etc.

Not all birds exhibit feather pecking. Usually only a few birds start but the behaviour is self-reinforcing and it may easily be copied by conspecifics. Eventually a larger proportion of the flock may be eager to perform this abnormal behaviour.
.

Stress/triggers

Whether or not a bird starts feather pecking depends on several factors, which will be described under the heading ‘Risk factors‘. However, these risk factors do not always cause injurious pecking behaviour. One theory is that stressors may build up to a threshold . The level of the threshold may be genetically determined, but it may also be influenced by earlier experiences. When the total amount of stress surpasses the threshold, birds will start to feather peck.

Balance of causes of feather pecking
Balance of causes of feather pecking
Tipping bucket model of feather pecking
Tipping bucket model of feather pecking (modified after Bracke et al. 2012).

.

Further reading

SPECIFIC

Scientific

GENERAL

English

FeatherWel - improving feather cover AssureWel - improving feather cover
FeatherWel management guide [pdf, 5.49mb] AssureWel advice guide [pdf, 661kb]

Nederlands

Treatment of feather pecking (in Dutch) Prevention of feather pecking (in Dutch)
Noodmaatregelen tegen pikkerij [Treatment of FP]. Van Niekerk et al. 2013 (Report, 32 pp). Van kuiken tot kip [Prevention of FP]. Van Niekerk et al.2011 (Report, 32 pp).

Dansk

Feather pecking key (in Danish)
Fjerpilningsnøgle [Feather pecking key]. Johansen, N.F. 2013 (Report, 48 pp).

Leave a Reply

Your e-mail address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.

This site uses Akismet to reduce spam. Learn how your comment data is processed.