Good news about the herons

A dull day, both in terms of weather and because there wasn't much to see. The Little Owl at the Round Pond was staying indoors.

While I was there I filmed a Pied Wagtail rushing around on the gravel strip, where an abundance of rather revolting droppings from the swans and geese attracts insects. Probably at this time of year it's getting mostly larvae rather than adult insects, though midges do persist through the winter.

Pied Wagtails will gather anywhere there are plenty of insects, and in cities that means places with cafés and street snack bars where a lot of food is spilt. Mark Williams photographed this one at the Tower of London, where the constant tourists are making a mess.

The most remarkable one I encountered was in the winter of 2012-13, in Queensway north of the park. This is lined with cheap resturants and snack bars. The wagtail was running around in the street, relying on its speed and rocketlike takeoff to dodge the moving cars. It was quite fearless and would come to take little bits of cheese thrown on the pavement. Here it is on a rainy evening in the light from a shop window.

Back to the Round Pond: I was wrong when I said that the number of Common Gulls was down this year. A couple of days ago Bill Haines counted 56, well up to average for midwinter. Here are five mixed in with the smaller Black-Headed Gulls. Common Gulls' winter plumage has dark streaks on the head, which makes them quite easy to spot. Usually they have pale off-white, yellow or grey legs, but those of the one facing away just right of centre are quite a dark grey.

A pair of Gadwalls, in the foreground of the first shot, and a pair of Mallards on the pond. The drakes are easy to tell apart, with the sober grey of the Gadwall completely different from the showy colours of the Mallard. But the females have much the same plumage. Gadwalls are a bit smaller than Mallards and narrower in build, while Mallards are quite broad in the beam. Gadwalls have dull orange-yellow legs and feet, Mallards a deeper orange. The real clincher is the colour of the secondary feathers of their wings, which you can often get a flash of even when they're folded. In Mallards of both sexes these are iridescent blue, as in the second shot. Gadwalls have white secondaries, which you can just glimpse for a moment in the third shot.

However, the Black Swan is no longer here. He has flown down to the Serpentine, where I found him this afternoon.

Good news: the Grey Herons' nest is still a going concern. The sitting bird showed when it got up for a moment. I didn't get the camera on it in time as it quickly sat down out of sight, so here it its mate standing on a post below. It won't be more than a few days before the eggs hatch: incubation takes about 25 days, a remarkably short time to grow their big gawky chicks.

Most Wrens are very shy birds which flee the moment they see you looking at them, and you have to snatch shots with great haste. This one appeared for just a couple of seconds in the brambles near Peter Pan.

But sometimes they just aren't bothered. This one perched on the back of a bench in the Rose Garden for a minute ...

... then flew down to forage in a flower bed, making no effort to hide.

Two Robins were singing at each other in the shrubbery.

Near the Speke obelisk a single Redwing perched in a tree ...

... and a pair of Stock Doves wandered along the branches.

The Coal Tit appeared again at Mount Gate.

The aggressive Black-Headed Gull kept an eye on his territory from the top of the Big Bird statue.

A young Cormorant at Peter Pan was losing its juvenile white front and beginning to get the all-dark plumage of an adult.

The youngest Great Crested Grebe was fishing by itself near the island.

The grebes that nested in the willow near the bridge seem to have left, taking their young one with them. They were probably frightened off by the recent frosty weather, and went up the river where the water never freezes over.