You need to look at more than a lovebird's beak to tell if it is a boy or a girl. It is possible to tell a lovebird's sex from its beak, but you cannot be sure. Male and female lovebirds are monomorphic, meaning they look the same. Sexing is accurately performed in budgerigars by observing the colour of the cere (nostril area), but this is not the case for lovebirds. Sexing lovebirds is not an exact science unless DNA testing or an operation is performed. There are a number of often imprecise methods that breeders use to determine the sex of a lovebird and examining the beak is only one.
Practice comparing male and female lovebirds in the pet store. Ask the owner to point out male and female lovebirds to you, so you can compare their differences. The differences between the sexes are so small that by examining only one bird, you have no measure for comparison. For example, the male is sometimes marginally bigger than the female; therefore you need to compare both sexes. Sex lovebirds more easily the more experience you gain.
Observe the beak. The beak of the male is slightly longer with a longer hook. The female's beak is a little broader. The female's head and shoulders are slightly broader. Having a correctly sexed bird for comparison is preferable.
Hold the lovebird belly up in your palm. Gently pin it down with the fingers of the same hand. With your other hand, put your finger between its legs. Feel two bony points just above the tail. If the points are close together the bird is male and if they are further apart it is female. This method is not exact and requires practice and comparison with other birds.
Observe the bird's behaviour. A female bird acts in an unusually aggressive manner if she is experiencing the urge to nest. Watch for nesting behaviours. If these behaviours are present then you have a female. Some female birds never exhibit these behaviours. A male lovebird is usually gentle and laidback. However, each bird is different and you may have a male with a consistently aggressive nature.
Find your lovebird laying eggs and be sure that she is female. However, some females never lay any eggs.
Take your lovebird to an expert for a professional opinion on its sex. Choose a lovebird breeder or pet store owner that specialises in birds. Still, even professionals can be wrong difficulty of sexing lovebirds.
Take your lovebird for a DNA test. The veterinarian will cut the bird's toenail far back enough to draw blood, which will be sent off to a laboratory for DNA testing.
Determine the sex of your lovebird by surgical procedure. If DNA testing is not available, an experienced veterinarian will perform a surgical procedure, whereby a small incision is made in the left side of its body under anesthetic. The procedure allows the vet to see the ovaries of a female bird. This method causes stress to the bird.
Subjecting your lovebird to the more extreme sexing methods, such as DNA blood testing and surgical procedure, is only recommended if you plan to breed your bird. Otherwise, save your lovebird the unnecessary stress of going through such procedures.