The RWAF recommends that pet rabbits are neutered and kept with another friendly rabbit. In our experience a neutered male / female pair works best. They are social animals and suffer from stress when kept without the companionship of their own species.
There is research to support this advice:
Research has shown that rabbits value companionship as highly as food. (Seaman et al 2008) (Lisiewicz et al 2009)Rabbits housed in pairs show a decrease in abnormal behaviour patterns, such as fur chewing and bar biting. (Khrohn et al 1999, Chu et al 2004)
All major welfare organisations in the UK agree with this advice.
Remember also that rabbits and guinea pigs are not suitable companions. Both species are social but need to be bonded with members of their own species.
We often hear that people think that their rabbits are happy alone, and can not be bonded. In our experience of over 20 years of rescue and bonding this is very rare. More likely the reason that rabbits do not bond sucessfully is because they are not introduced property or because those two particular rabbits are simply not compatible. There is a lot of advice out there, but not all of it is based on fact. We pride ourselves on providing up to date and correct information.