Zebra finches originate from Australia and Indonesia, and have been kept as pets for centuries. As social birds, they prefer to be kept with others of their own kind, but occasionally friction can occur between roommates. With some careful planning, it's usually possible to stop your finches from fighting with each other.
Play the Numbers Game
Keeping the wrong number of zebra finches together can cause them to fight. For the most part, a single pair of finches will live together harmoniously, whereas two pairs will start fighting with one another over resources. However, if you introduce a third pair, the fighting generally stops, as it takes away the pressure of just one pair being dominant and the other being submissive. You may find that three pairs will squabble with each other slightly, but it rarely ventures into the territory of serious fighting.
Not only will your zebra finches be unhappy living in too small a cage, it also may cause them to fight with one another as they're unable to stake out a territory for themselves. To avoid your finches getting in each other's personal space, make sure you keep a single pair in an aviary that's at least 24 inches long, 18 inches wide and 18 inches high. If you're planning on keeping three pairs together, their cage should be a minimum of 60 inches long, 20 inches wide and 20 inches high.
If you're keeping a same sex pair or pairs of zebra finches, remove any nests from their cage. They often will fight over whichever one they perceive to be in prime position. It's best to avoid placing nests altogether, unless you want a mixed sex pair to breed, as the presence of nests is likely to trigger territorial behavior. If you're keeping multiple pairs in the same cage and you do want them to lay, make sure you install more nests than there are pairs to reduce the chance that they will fight over them.
Perches are another item that can inspire territorial fighting between zebra finches. Minimize the risk of them squabbling over a certain perch by placing several of them on different walls of the cage and on different levels. It's best to have a couple more perches than you have finches. If your birds are pushing each other off perches during their fights, putting clothes pins on the perches, roughly six inches apart, can help to establish boundaries and stop disagreements.
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