src: 3.bp.blogspot.com
A hybrid lovebird is the result of two species lovebirds being cross-bred. Hybrids produced by the pairing of a rosy-faced lovebird (or peach-faced lovebird) with one of the "eye-ring" species (i.e. those species which have a prominent area of white bare skin encircling the eye, Fischer's lovebird being a typical example) are usually sterile - whereas crosses between the "eye-ring" species are often fertile.
Video Hybrid lovebird
References
Source of article : Wikipedia