Feather destructive behaviour (FDB) is a prevalent and distressing issue in captive birds, especially parrots. This condition encompasses a range of behaviours, including chewing (Figure 1), feather plucking (Figure 2) and self-mutilation, which not only damage the bird’s plumage but also indicate deeper health or environmental issues that require veterinary intervention.
Clients presenting their birds for feather destructive behaviour often believe it is an issue with boredom or external parasites, but in reality, there are hundreds of possible causes of FDB. Determining the cause is, therefore, essential for appropriate treatment. Understanding the multifaceted causes and implementing effective diagnostic and management strategies are crucial for the treating veterinarian.
This article delves into the most common underlying causes of FDB, diagnostic approaches and management options for these cases.
The origins of feather destructive behaviour
The origins of FDB in birds are multifactorial, involving medical, psychological and environmental factors.
Medical factors
Any condition that results in pain or discomfort can be a cause of FDB.
Dermatological conditions are a significant cause of FDB; for example, bacterial, fungal and viral infections (Figure 3) and parasitic infestations cause skin irritation and lead to feather plucking (Van Zeeland et al., 2016). For instance, mites and lice are common ectoparasites that can provoke intense itching and discomfort, prompting birds to pluck their feathers. Similarly, bacterial infections (Figure 4), such as Staphylococcus spp., and fungal infections, such as aspergillosis, can cause dermatitis, leading to FDB (Schmidt and Lightfoot, 2010).
Nutritional deficiencies are another major contributor to FDB. A lack of essential amino acids, fatty acids and vitamins can compromise feather quality and skin health. Birds fed a seed-based diet are particularly at risk due to the unbalanced nutrient profile of such diets (van Zeeland et al., 2009). For example, deficiencies in vitamin A, which is crucial for skin and feather health (Figure 5), can lead to hyperkeratosis and secondary infections, exacerbating FDB (Koutsos et al., 2001). Specialised pelleted diets that deliver a balanced and species-appropriate nutrient and mineral profile are available for parrots from many reputable companies as an alternative to seed-based diets.
Systemic diseases, including hepatic disorders and endocrine imbalances, can also contribute to FDB. Liver disease is known to cause pruritus, leading birds to pluck their feathers (van Zeeland et al., 2009). Endocrine disorders, such as hypothyroidism, can disrupt normal feather growth and health, leading to poor feather condition (Figure 6) and increased skin sensitivity, resulting in FDB (van Zeeland et al., 2009).
Birds have also been shown to pick feathers over areas of pain or discomfort (Figure 7). This can be seen in birds with musculoskeletal disease, such as arthritis, or systemic diseases, such as aspergillosis, Chlamydia, bacterial or fungal gastroenteritis and Giardia spp. infections in cockatiels (Raftery, 2005).
Psychological factors
Psychological factors play a crucial role in the development of FDB. Stress, boredom and anxiety are common in captive birds due to inadequate environmental enrichment and social interaction (Meehan et al., 2004). Birds are highly intelligent and social animals, and a lack of mental stimulation and/or socialisation can lead to significant behavioural issues, including FDB (Kim et al., 2009). Stressors such as changes in routine, the loss of a companion and new household members can trigger or exacerbate FDB (van Zeeland et al., 2016).
Additionally, captivity itself can be inherently stressful for birds. The limitations on natural behaviours such as flying, foraging and social interaction can lead to frustration and self-destructive behaviour. The impact of captivity stress is well documented, with numerous studies linking it to FDB in various bird species (Meehan et al., 2004). In particular, birds that naturally live in large flocks and have complex social structures will struggle living as a solo bird, especially if left alone for long stretches of time.
Environmental factors
Environmental factors are critical in the development of FDB. Poor housing conditions, such as inadequate space, improper lighting and a lack of environmental enrichment, can contribute to stress and boredom, exacerbating FDB (Meehan et al., 2004). For example, insufficient space restricts natural movement and exercise, leading to frustration and destructive behaviours.
Proper lighting is also essential, as inadequate lighting can disrupt circadian rhythms and negatively impact a bird’s psychological well-being
Proper lighting is also essential, as inadequate lighting can disrupt circadian rhythms and negatively impact a bird’s psychological well-being (van Zeeland et al., 2016). Ultraviolet (UV) lamps designed specifically for use in birds can help to provide natural lighting and exposure to healthy levels of UVB.
A study into risk factors associated with FDB in African grey parrots and cockatoos showed increasing hours of sleep and length of ownership were significantly associated with FDBs in African grey parrots (Jayson et al., 2014). The authors also found that being purchased from a pet shop, a cage location against a wall and annual vacations taken by owners were associated with FDBs in cockatoos.
Exposure to environmental toxins, such as cigarette smoke or household chemicals, can also irritate the skin and feathers, leading to FDB. Toxins can be ingested, inhaled or absorbed through the skin, causing systemic health issues that manifest as feather destructive behaviour (Rubinstein and Lightfoot, 2012). Birds are particularly sensitive to airborne toxins due to their efficient respiratory systems, making environmental control crucial for preventing FDB.
Diagnostic approaches to feather destructive behaviour in birds
Accurate diagnosis of FDB involves a comprehensive approach that includes a detailed medical history, thorough physical examination and targeted diagnostic tests. A thorough medical history is the first step in diagnosing FDB and should include information on the bird’s diet, environment, previous health issues and any changes in routine or behaviour. Observing the bird’s interaction with its environment can provide valuable insights into potential psychological or environmental stressors (van Zeeland et al., 2016).
A thorough medical history is the first step in diagnosing feather destructive behaviour and should include information on the bird’s diet, environment, previous health issues and any changes in routine or behaviour
During the physical examination, veterinarians should look for signs of dermatological conditions, nutritional deficiencies or systemic diseases. Skin and feather condition, as well as overall body condition, should be carefully evaluated. The presence of ectoparasites, skin lesions or abnormal feather growth patterns can provide clues to the underlying cause of FDB (Van Zeeland et al., 2009).
A variety of diagnostic tests can help identify underlying medical conditions contributing to FDB. Skin scrapings and feather pluck biopsies are useful for diagnosing dermatological issues, including bacterial, fungal and parasitic infections (Koski, 2002). Blood tests can reveal nutritional deficiencies, liver or kidney diseases and endocrine disorders. For example, elevated liver enzymes can indicate hepatic disease, while abnormal thyroid hormone levels can suggest hypothyroidism or hyperthyroidism (Oglesbee, 2004).
Imaging studies, such as radiographs or ultrasound, can help diagnose internal organ diseases. These tools are particularly useful for identifying hepatic or renal disorders that might be contributing to FDB. Additionally, advanced diagnostic techniques such as endoscopy or biopsy may be necessary to diagnose specific conditions such as aspergillosis or neoplasia.
Management of feather destructive behaviour in birds
Effective management of FDB requires addressing the identified underlying causes through combining medical treatment, behavioural modification and environmental enrichment.
Treating medical conditions
Treating underlying medical conditions is crucial for managing FDB.
Dermatological issues should be addressed with appropriate antimicrobial or antiparasitic treatments. For example, bacterial infections may require topical or systemic antibiotics, while fungal infections might necessitate antifungal medications. Parasitic infestations should be treated with suitable antiparasitic drugs, and preventive measures should be implemented to avoid reinfestation.
Nutritional deficiencies can be corrected through dietary modifications and supplements, ensuring a balanced intake of essential nutrients. Providing a varied diet that includes fresh fruit, vegetables and specially formulated bird pellets can help prevent deficiencies and promote overall health (Koutsos et al., 2001).
In cases of systemic diseases such as liver or endocrine disorders, appropriate medical management should be instituted based on established veterinary protocols. For example, hypothyroidism might be treated with thyroid hormone replacement therapy, while liver disease may require dietary changes and supportive care (van Zeeland et al., 2016).
Behavioural modification
Behavioural modification strategies are essential for reducing stress and boredom, thus alleviating FDB.
Increasing social interaction, either with other birds or through human engagement, can significantly improve a bird’s mental well-being (Meehan et al., 2003). Structured playtime and training sessions can provide mental stimulation and strengthen the bond between the bird and its caregiver. Providing a variety of toys, foraging opportunities and puzzle feeders can enhance environmental enrichment and reduce boredom.
Toys should be rotated regularly to maintain the bird’s interest and prevent habituation. Foraging activities mimic natural behaviours and can help occupy the bird’s time and attention, reducing the likelihood of FDB (Lumeij and Hommers, 2008).
Predictable feeding times, play sessions and sleep schedules can contribute to a stable environment, minimising anxiety and stress-related behaviours
Additionally, implementing a consistent daily routine can help reduce stress and provide a sense of security for the bird. Predictable feeding times, play sessions and sleep schedules can contribute to a stable environment, minimising anxiety and stress-related behaviours (Meehan et al., 2003).
Changing the environment
Environmental enrichment involves improving the bird’s living conditions to reduce stress and promote natural behaviours. Ensuring adequate space, proper lighting and a variety of perches and toys can greatly enhance the bird’s quality of life (Meehan et al., 2004). For instance, providing a spacious cage or aviary allows for natural movement and exercise, while diverse perching options can cater to different preferences and needs.
Proper lighting is crucial for maintaining circadian rhythms and supporting overall health. Full-spectrum UV lighting that mimics natural sunlight can help regulate sleep patterns and improve mood and behaviour. Additionally, providing access to natural sunlight, where safe and feasible, can offer health benefits beyond artificial lighting (West et al., 2019).
Minimising exposure to potential toxins is also critical in managing FDB. Birds should be kept away from cigarette smoke, household chemicals and other environmental pollutants. Regular cleaning of the living area, proper ventilation and using non-toxic cleaning products can help create a safe and healthy environment for the birds (van Zeeland et al., 2009).
Conclusion
Continuous research and education are essential to develop and implement effective strategies for managing this challenging behavioural problem
Feather destructive behaviour in birds is a complex issue that requires a thorough and holistic approach to diagnosis and management. By addressing medical, psychological and environmental factors, veterinarians can significantly improve the health and well-being of affected birds. Continuous research and education are essential to develop and implement effective strategies for managing this challenging behavioural problem. Through comprehensive care and attention to detail, veterinarians can help reduce the incidence of FDB and enhance the quality of life for captive birds.
