LIGHT: Implications in Feather Mutilation Behavior

Abstract

F eather Mutilation Behavior - three dirty words in parrot aviculture. The causes of this behavior and ways to resolve it challenge avian veterinarians, behaviorists, breeders and companion parrot owners. People whose parrots exhibit these behaviors often feel frustrated and even ashamed when they are unable to resolve the problem. Even parrots in "good" health, eating a "good" diet, and receiving "good" care, social guidance, and mental stimulation, can suffer from it.

What is

Feather Mutilation Behavior?

Briefly described, feather mutilation behavior, also known by such names as feather abuse, picking, or barbering, is when a parrot picks, plucks, chews, shreds, amputates (etc.) his/her feathers. The bird may even mutilate his own body, or may extend the feather or body mutilation to his mate or cagemates. The seriousness of the condition to the health of the bird may vary from a scruffy appearance to illness and death.

Any level of feather mutilation behavior indicates that something is "not right" with some aspect of the parrot's life.

Many articles have been written about possible causes of and treatments for this behavior. In several of these articles, authors point out that the cause of much feather picking behavior seems to originate with a physical problem, such as disease, parasites, or injury. Tammy Jenkins, DVM, in her article "The Basics of Feather Picking" 1 lists 10 of its most

likely significant causes. Interestingly, the last item on the list is behavior. Behavior, once thought to be among the first of most significant causes, seems to be considered less so by a growing number of professionals.

Endocrine/Re productive Disease and Hypothyroidism are third and sixth on Dr. Jenkins's list. She indicates that some endocrine stress may be due to the absence of stimuli that cause natural cycles of breeding. Possibly owners of birds in captive conditions may unknowingly house them in ways that keep them constantly in a breeding or near-breeding state. Dr. Jenkins lists drug therapies that seem to have been helpful in reducing picking behavior from reproductive stress. These include Depo-Provera (medroxyprogesterone acetate) a synthetic progesterone, HGC (human chorionic gonadotropin), and Lupron (a synthetic type of gonadotropin-releasing hormone) that "works by obliterating blood levels of estrogen or testosterone for weeks or months."

Other drugs that may relieve some feather picking due to endocrine issues may include antiseratonin drugs and melatonin. Dr. Jenkins suggests that, in addition to drug therapies, changing the environmental triggers for reproductive behavior, such as removing perceived nesting sites, reducing daylight hours, and changing aspects of the diet may be helpful.

Slow, difficult, or abnormal molts may also contribute to feather picking. Old feathers may become frayed and worn, and the bird may

overpreen, possibly in an attempt to smooth them. Birds exhibiting a slow molt may be tested for hypothyroid. Thyroid tests, such as T4, are often not reliable in birds, which can make problems from this cause difficult to diagnose. Dr. Jerry LaBonde, MS, DVM writes in his article "Feathers" 2 that "Abnormal molts can be ... a sign of illness, poor nutrition, or an imported bird to northern latitudes."

A Common Thread

There is a common thread that weaves through these two causes of feather picking that may warrant more thorough investigation. That thread is the importance of Light.

In the article "The Visual Capabilities of Birds," William Hodos' states, "Of all the vertebrate classes, birds are the most visual dependent. Many aspects of their adaptation to their environment and their survival depend on precise and sometimes quite subtle visual discrimination." In the article "Light and its Role in the Breeding of Birds," Patrick Thrush' states "Of all creatures, birds show us the most dramatic response to changes in photoperiod. Lengthening or shortening the amount of light in a day triggers migrations, molting, nestbuilding and breeding."

The eyes of most birds are very large in proportion to their bodies,' and the portion of their brains devoted to processing information from the eyes is well developed. This indicates that collecting and processing visual stimulus (light) is critically important to the survival of birds. Two avenues for interpreting light conditions are utilized" - the eye/retina and an organ that surrounds the eye, called the Harderian Gland. Light is gathered for the purpose of creating a visual image (sight) and for transmission of information about day length and light quality to the pituitary gland and to the pineal gland, the "master clock" of the body. In his article "Using Full Spectrum Lighting With Birds,"7 Patrick Thrush states, "Taken together, these two pathways set the pace for all subsequent endocrine related metabolic processes."