A simple vocalization that a parrot uses to stay in touch with other flock members (bird or human).
In the wild, contact calls are likely to be species related, but this often appears to not be the case with domestic-bred parrots. Instead, domestic-bred birds often use contact calls based on sounds they have learned from the human habitat. So sounds can be quite individual in captivity. Owners can identify their own bird's contact call by paying attention to the bird's communications.
This is a normal survival behavior. The contact call helps the bird make certain the flock has not left it behind, as safety is highest with the flock.
Always respond to a contact call, so the bird's vocalizations do not escalate to a full scream in an effort to get a response. Failing to answer a contact call is likely how many/most parrots learn to scream excessively, as many people did not understand the significance and ignored a contact call. Unfortunately, few people can refrain from yelling at a parrot that screams for hours, so they inadvertently teach a bird that only loud shrieks get the desired response.
Disclaimer: BirdChannel.com's Bird Behavior Index is intended for educational purposes only. It is not meant to replace the expertise and experience of a professional veterinarian. Do not use the information presented here to make decisions about your bird's health if you suspect your pet is sick. If your pet is showing signs of illness or you notice changes in your bird's behavior, take your pet to the nearest veterinarian or an emergency pet clinic as soon as possible.