Bird Amplifiers have all-but been forgotten for forty years. They seem to have only been produced for about five years or so in the early to mid-sixties, and not that many were sold compared to Selmer, Watkins, and Fenton-Weill. That is a pity, because they are well built amps with features that were in the forefront of UK amplifier design in the early 1960's.
They were produced from about 1960 onwards by Sydney S. Bird and Sons of Poole, Dorset who, amongst many other things, were into the manufacture of electronic organs. Perhaps effects such as reverberation, tremolo, and delay being fairly common on electronic organs back in the 1960's, made it seem logical to Bird to start building guitar amps as well. Certainly, by the time of the 1966 British Music Instrument Trade Fair, Bird were only featuring keyboards and organs on their stand again. They presumably found that the competition from the likes of Vox, Selmer, Watkins, and also by that time, Marshall, made it difficult to compete in the guitar amp business.
A very brief history of Sydney Bird's other manufacturing adventures can be found ELSEWHERE on this website.
The Bird Company's product line was very much dominated by electric organs, as can be seen from this advertisement from August 1965.