My female parakeet has a lump under her tail and sits on the floor of her cage a lot. Is this normal? She’s lived in a cage with a male parakeet for five years, but this is the first she’s ever shown these signs. Could she be pregnant, or could this be a "false pregnancy?"
You should seek veterinary care for your bird immediately. Sitting on the floor of the cage is never normal, and it sounds like your little parakeet is "egg-bound." If this is the case, then her life is in danger.
Female birds (most commonly budgerigars/parakeets, cockatiels, finches and some other species) can become stimulated to lay eggs without breeding. This can happen in response to the presence of a male, hormonal imbalances, exposure to constant periods of light and dark that mimic springtime, or actual breeding with a male bird. The eggs are often sterile, i.e. they contain no viable chick.
This egg laying will often continue if the egg is sterile, or if the egg is removed immediately, but the stimulus to lay still exists. Such chronic egg laying can deplete the female bird’s stores of calcium and other nutrients. Calcium is necessary for muscle contractions, which push the egg through the birth canal. Therefore, lack of calcium from chronic egg laying can potentially result in the egg becoming lodged in the birth canal because the muscles no longer work well enough to push the egg out. The final result: a bird in dire need of immediate veterinary care and a break from laying eggs!