Hi,
Is this a tame bird that you can handle? If so, I would not recommend getting another bird. At his age, he is used to humans as his companions. Even if he isn’t hand tame, it sounds like he is happy to be around people. He is probably too old to accept or identify with another cockatiel. Possibly another senior, but as you said, that isn’t likely. He may have months to a few years left. He has already lived far longer than most cockatiels these days. If you get a younger male, it would likely bully him. Two males raised together generally get along, or two males around the same age that are introduced often do well together. But when there is an age difference, you end up with a young bird in peak condition and an older bird in his final life stage. Instinct can cause the young male to not want an old bird around – in the wild this could put the flock at risk. If you get a female, then you have a similar situation – a female that will get hormonal and will have no use for an old bird that may be past the ability to breed. It doesn’t matter if you don’t intend to breed, if you have a male and female, hormones kick in eventually. I would make sure this bird has plenty of toys, interaction with people and have him in a family room where there is activity to stimulate him and keep him enriched. When the house in empty, he is likely to nap, but leaving some music or a TV on can keep him company. If you do get another bird anyway, it has to be in a separate cage. And keep in mind that you will soon end up with a single bird again. Since this bird is talkative and active, these are signs of a happy bird that has adjusted well to his new home. He may miss his late owner, but he doesn’t sound lonely.
Thank you for asking Lafeber,
Brenda