Severe feather-pecking (SFP) is when birds vigorously peck at and pull out the feathers of other birds. It is a prevalent behavioral problem in chickens, and often results in extensive feather loss, traumatic injuries, and sometimes death of the birds' under attack. SFP can also quickly lead to cannibalism among flock members if it is not dealt with promptly and correctly. There are a number of different causes of feather pecking in birds which include:
- Housing Conditions: Overcrowded living conditions, excessive light, and not providing enough nest boxes or roosting space for flock members can result in feather pecking.
- Environmental Stresses: Birds exposed to high temperatures and occurrence of abrupt weather changes can stress birds, leading to aggressive behavior.
- Diet: When birds receive inadequate amounts of protein, phosphorus, and sodium in their diet, an excessive high-energy and low-fiber diet, or lack of fresh greens, they can develop aggressive behavior.
- Management Related: Since chickens tend to instinctively prey on the sick and injured, any injured birds should be relocated to a separate area, away from other birds until fully recovered.
- Flock size: Flock size should include more than or less than 30 birds. When flocks have 30 birds, they tend to have ore problems within their social hierarchy.
- Group Dynamics: Feather pecking also occurs more often in flocks which combine birds of different ages, breeds, colors, or sizes that have not grown up together.