Delicate birds, budgies may appear to tremble for a variety of reasons. Trembling might be a display of normal behavior or a warning sign of underlying health concerns. Birds naturally try to conceal illness -- it's a defense hedge against predation in the wild. If your bird's trembling, then, there's a chance that she's sicker than she's letting on. Seek medical attention right away.
Your budgie may tremble due to stress. Trembling can be a natural and temporary behavior if she’s settling into a new household. Otherwise, some environmental factor might be frightening your bird. For example, if your budgie trembles every time loud music comes on the television or when your dog starts to bark, you can attribute these actions to the bird's being startled or scared. If she exhibits this behavior when the house is quiet and there's no activity about, you'll need to look further for the cause.
Budgies often appear to tremble as part of their normal grooming routine, which can include ruffling their feathers, particularly after preening. If you give your budgie a bird bath, you may see this behavior exhibited as your bird dries and fluffs her feathers. A tremble could also be a temporary shiver associated with a cooling bath. If your budgie exhibits excessive preening or begins to pick her feathers or her feet, she should see a vet, as this is a sign of stressed behavior.
Some budgies become very animated as they’re getting ready to fly. This is particularly pronounced in budgies with clipped wings, who are unsure of their flight capability. Along with the trembling behavior, you may see your budgie alternating feet on the perch, and bobbing forward and backward, as she revs up to take off.
Budgies who are sick may look wilted and lethargic. They may tremble on the perch or become unsteady and sit on the bottom of the cage. This type of behavior, especially when accompanied by lack of appetite and crusty or runny eyes, cere or beak, should have an evaluation by a vet. A budgie experiencing any type of convulsions or trembling that won’t stop needs a qualified medical professional as soon as possible. According to Dr. Ross Perry's BudgieHealth website, by the time a budgie starts to exhibit these kinds of signs, she likely has a variety of medical issues going on that need emergency care.
Lisa McQuerrey has been a business writer since 1987. In 1994, she launched a full-service marketing and communications firm. McQuerrey's work has garnered awards from the U.S. Small Business Administration, the International Association of Business Communicators and the Associated Press. She is also the author of several nonfiction trade publications, and, in 2012, had her first young-adult novel published by Glass Page Books.