Why Do Parakeets Swell Up?

An experience common to many parakeet owners is the phenomenon of seeing their parakeet swell up or puff out their feathers. This is not unusual and can mean various things ranging from normal to serious.
  1. Reason

    • When parakeets fluff their feathers, they are trying to keep warm. This gives the bird a "swollen" appearance, but by loosening its feathers, the animal is able to trap more air between them. This allows it to retain more heat since the captive air helps insulate the bird from its cooler surroundings.

    Sleep

    • The most common reason a parakeet swells its feathers is that it the animal is tired and preparing for a nap. The fluffing action prevents heat loss during the bird's period of inactivity and the normal depression of its metabolism during sleep.

    Illness

    • If a bird remains fluffed for hours or even days, it can be an indication of a potentially serious health issue. Parakeets that do this are likely ill and should be seen by a vet and separated from uninfected cage mates.