Lovebirds can be particular about their companions, but two female lovebirds can bond and become a pair -- it frequently happens when two female birds are inadvertently housed together. Two male lovebirds can also bond. Meanwhile, even paired male and female lovebirds must get along as cage mates to breed.
Two Isn't Better
The common myth that lovebirds must be kept in pairs is not true, although these energetic and lively birds are frequently housed together. Many breeders recommend keeping a single lovebird as a pet, because two will bond so closely that they can exclude their owner. A single lovebird views her owner as her flock, rather than her birdie companion. Female lovebirds bonded to each other can become nippy with their owners.
How to Tell Gender
The difference in appearance between lovebird genders is so slight that it's hard to tell males from females. Female lovebirds tend to be more aggressive, and their bodies are a bit broader than males'. They stand with their legs slightly further apart. The only way to positively determine your bird's sex is to have an avian veterinarian perform a pelvic check, take a DNA sample or do a surgical examination.
Male vs. Female
Female lovebirds can bond if they are placed together at a young age. Female birds are known for being territorial about their cages; they sometimes pick on male companions if they live together. Male lovebirds are slightly less noisy than females. Both males and females chatter and chirp all day, but female birds also scream. Females are more aggressive than males, so early training and socialization is required.
Introducing the Birds
Before placing two female lovebirds together, make sure they get along. If they are both territorial, they will fight when they're in the same cage. Start with the birds in separate cages next to each other and watch for signs of aggression. Be sure your cage for two birds is spacious -- a minimum of 32 inches by 20 inches by 20 inches. The cage should have room for four perches and space for several feed dishes. Supervise the birds closely when they are placed together.