Zoom more?

The foxes will curl up in the middle of the garden and sleep, they will also stretch out and appear to be asleep. But I can’t get close enough.

I’m using a Tamron 70-300mm and right outside the back door this is the full view.

And this is as close as it will focus. Ignore the fact it isn’t in focus – the point was how much of the frame I can fill with his face.

Is another lens the only way I can get closer or would a converter be a good route?