My next door neighbour always has a wildlife query when we have our little chats over the fence, and this week he had seen something he'd never seen before.

"It had a long tail and was scurrying all over my patio. Would I be right in calling it a Long-tailed Tit? Is there such a thing?"

I pushed for a little more detail. Yes, it was on the ground, and it had a yellow undercarriage.

The penny dropped. "Ahh, yes! A Grey Wagtail. How wonderful."

"Grey?" He sounded surprised at the name. "That's not the normal wagtail, then?"

"No, that's the Pied Wagtail you might see running around car parks. This one is a rarer creature altogether. I've had one coming down to my pond in the last couple of weeks and I reckon yours is likely to be the same one, running about to find any tiny insects it can find on your slabs."

And here is said wagtail, on the log in my pond - a fine looking bird, I'm sure you'll agree. Come the breeding season, it will develop a jet black throat (or freckled if it is a female) and an even yellower breast.

Now this story is not to disparage the identification skills of my neighbour one iota. I love the fact that he is taking time to notice these things and then using me as his sounding board.

I was able to tell him that it is typically a bird of fast rushing rocky streams, weirs and cascades; indeed, it seems to have a fixation on the sound of rushing water, to the extent of being lured down by little garden fountains.

What we also suspect is that Grey Wagtails are to some degree what are called altitudinal migrants, moving from higher ground down to lower. Just as the Redwings and Fieldfares of winter are our garden connection to the forests of Scandinavia and beyond, and our House Martins and Swifts are a link to the skies above the tropics of Africa, so winter Grey Wagtails are garden connections to upland areas.

I can't be wholly sure, of course, that my (and my neighbour's) Grey Wagtail had not come from some millrace somewhere in Sussex, but it is just as likely that it had come from some mountain stream in Wales, Northern England or Scotland.

Of course, one of the things that stood out in the conversation was his surprise at the name of Grey Wagtail, given that the yellow 'undercarriage' was what had stood out most for him.

The name does indeed throw many people, who think that it must surely be a Yellow Wagtail, but those are summer visitors that skip around the feet of cattle in wet grassy meadows. It's one of those birds that, if we were hyopthetically to start the naming process all over again, would surely get a new title. Maybe Torrent Wagtail, but then that wouldn't help my neighbour on his patio!

Or maybe I'd go for Really Waggy Wagtail, because with a tail this long, it really can seesaw backwards and forwards with great vigour.

Sadly, it is another of those species that sits on the UK Red List, those species of greatest conservation concern. Its numbers fell sharply in the 1970s and 80s and again after 2002, although encouragingly there has been a bit of a recovery in the last few years. We just don't know the reasons for these fluctuations, although it is thought to be some problem with survival once they have fledged.

So, if you do have one drop in to the open margins of your pond, or if you are really lucky onto your patio, revel in the yellow, chuckle at the intense wagging, and use the moment as a reminder that our gardens aren't islands unto themselves. This is an interconnected world, and what we do in our gardens is all part of the bigger picture.