“It’s the most difficult programme to make because Autumn is a flexible season.
“Spring pretty much has to happen, and it’s down to temperature day length, which triggers all of that animal activity.
“Autumn is very much shaped by the spring and summer that have come before it, weather in other parts of the world and that affects all of our species.
“It’s the most difficult but I think it can be the most beautiful. I don’t mind winter either.
“A lot of people think winter’s a time when everything shuts down, dead or hibernated but in fact, there’s an enormous amount of activity.”
Autumnwatch is available to watch on BBC iPlayer.