Whether you have one pet budgie or an aviary full of champion macaws, limiting stress is essential for the health and well-being of your birds. Stress can occur in many different forms, both physical and mental, and range from mild to severe. Stressors cause the release of a hormone known as cortisol from the adrenal glands. While in the initial stages of stress this hormone helps the bird’s body deal with its effects, in the long run it can cause the bird to be immunologically suppressed and unthrifty.
Stress typically occurs in three stages. The first stage is commonly known as "fight or flight."
In this stage, the bird first responds to the stressor with an adrenaline surge, which prepares the body for action by shutting down the non-essential functions, such as digestion, and increasing essential functions such as heart rate and blood sugar levels, while also dilating air passages. A cortisol surge at this time also helps reduce the pain and swelling that may occur with an injury so that the bird can escape from predators. In the second stage, called the "stage of resistance," the initial adrenaline surge subsides, but blood cortisol levels remain high for as long as the stressor remains in the bird’s environment, keeping the body ready for action. In the third stage, called the "stage of exhaustion," the high cortisol levels start to take their toll by suppressing the bird’s immune system and allowing dormant infections to become active or predisposing the bird to infection by opportunistic organisms. It can also affect the cardiovascular and gastrointestinal systems, as well as inhibit reproduction. Birds that have been stressed for prolonged periods may develop changes in their feather growth known as "stress bars," lines on the feathers perpendicular to the axis of feather growth.
There are many factors that can cause stress in a bird's life, and in order to limit stress, one needs to know what causes it. The following is a list of some common stressors and what you can do to prevent them from becoming a problem.
An underlying disease process is a common cause of stress. Remember even though they are your pets, your pet birds still have the instincts of wild animals, and therefore will try to hide illnesses for as long as possible. As underlying infections or organ disease tax a bird's reserves, any other added stressor might allow the bird to succumb to the disease. Frequent gram negative or yeast infections may be an indicator of a more serious underlying disease process or chronic stressor that results in immune compromise. Organisms such as chlamydia (psittacosis), polyomavirus, and psittacine beak and feather disease (PBFD) can be carried asymptomatically in otherwise healthy birds, and can emerge to infect other birds with the carrier is stressed. For these reasons, regular (annual) veterinary check ups are essential for your bird's good health.
Malnutrition is probably the most common cause of illness in pet birds. Birds that do not eat a well-balanced diet often develop nutritional deficiencies that can both directly and indirectly affect their immune system. While birds that eat an all-seed diet are not getting enough of 23 different essential nutrients, it is usually the lack of vitamin A that causes the first problem. The lack of vitamin A causes changes in the mucus membranes that predispose a bird to respiratory infections. Other nutrients are essential in normal liver function, bone growth, metabolism, etc. The chronic changes caused by these deficiencies result in underlying disease processes that act as stressors.