Lone Black Swan

I would be very grateful for any advice.

We moved house 18 months ago & inherited a lone black swan, who didn't have a name so we call it Graeme.

Graeme depends on us for food and company and doesn't move very far from the pond, which is a decent size. Unfortunately we don't know Graeme's sex or age. We know there were three black swans here at one time but don't know how long ago the others died. One was hit by a car so may have been young.

Graeme has become very tame since we have no scary dogs, and doesn't seem to mind our two cats who also don't mind the swan. They all sit together in the garden.

We are not outside so much in the winter and are concerned that he is probably very lonely especially as s/he now comes to the back door to find us, and not only when s/he wants food.

A few miles down the road there is a swan breeder, presumably where Graeme comes from, so we could probably quite easily get some black swan company for Graeme, but we don't know if this is the best thing to do. I don't know if they sell single swans or just pairs, and we don't want to do anything that might upset him/her.

I have read that black swans can find company with a same sex companion, so maybe we would not need to catch Graeme to find out his/her sex, which I think would be very upsetting - as I always respect his/her space and do not come too close.

I would be so pleased to know what would be the best thing to do for the health and wellbeing of Graeme. Thank you.