Thursday, 19 February 2015

Two pairs of Grey Herons are still building nests on the Serpentine island. One pair, in the smaller nest, had just been mating when I arrived. Then one of them took off and went down to the ground to collect more twigs.

A heron from the other nest was there already doing the same, but they kept far enough apart to avoid a fight. It is surprising how these big birds with huge wings manage to fly in and out of trees, but the fact that they can leap vertically into the air and fly very slowly is clearly a help.

In the Diana fountain enclosure, the usual pair of Herring Gulls were searching for worms, doing the usual worm dance, pattering their feet to imitate the noise of raindrops to bring up worms. In fact it was really raining, but not very hard. They were joined by a pair of Lesser Black-Backed Gulls, and one of them copied the worm dance, not something that Lesser Black-Backs usually do.

It only did short bursts of dancing, alternating with pecking the ground. Different worm-charming techniques may work equally well.

A pair of Mute Swans were wandering around on the steep grass bank behind the Lido waterfront.

A pair, possibly the same one, built a nest here last year under the concrete steps. It was a silly place to choose and was soon abandoned.

A large flock of Long-Tailed Tits was moving through the trees along the south edge of the Serpentine. Here is one of them hanging upside down from a twig in the ceaseless quest for insects.

The Maned Goose was still on the edge of the Round Pond, resting on one leg and half asleep. When an Egyptian Goose came too near, the irritable bird woke up just enough to threaten it before dozing off again.

An Egyptian on the edge of the pond turned downwind, allowing its feathers to blow about untidily.

There was a party of Shovellers under the bridge, allowing a top view.

You can see both its eyes from above. Most ducks can see directly overhead, a useful aid to survival on open water when there are predators about.

The male Tawny Owl was back in his usual place on the nest tree.



  1. Johanna in California19 February 2015 at 21:52

    Interesting about the Lesser Black-backed Gull trying out a worm dance. I'm starting to wonder now if I have seen our Common Ravens attracting worms with a croaking sound, which they make while hunting around in the grass. I read that some sounds that cause worms to move may resemble the sounds of their natural underground predators approaching them.

  2. A very interesting question. Sometimes, when a gull is doing the worm dance, you can see an immediate effect, as here -- this is one of the usual pair of Herring Gulls in the Diana enclosure. In favourable conditions it might be possible to see something similar with a Raven.

  3. The town of Sopchoppy, Florida, has held an annual "Worm Gruntin' Festival" since 2000. The event includes a ball and the crowning of a "Worm Gruntin' King and Queen".
    From Wikipedia along with many theories of why worms are encouraged to surface by noises made by birds and animals, including humans. Most likely seems to be that the 'dance' of some birds imitates the sound of rain and worms love to come to the surface when it's wet.

    1. I've seen videos of worm-charming (or possibly gruntin') contests, from which is is clear that many different techniques are used, and at least some of them work quite well. Evidently it's the same with birds. Before today, I have seen Lesser Black-Backed Gulls repeatedly pecking the ground, more rapidly than they would if they were just picking up food, and I suppose that the repeated shock also brings up worms.

  4. “Worms do not possess any sense of hearing. They took not the least notice of the shrill notes from a metal whistle, which was repeatedly sounded near them; nor did they of the deepest and loudest tones of a bassoon. They were indifferent to shouts, if care was taken that the breath did not strike them. When placed on a table close to the keys of a piano, which was played as loudly as possible, they remained perfectly quiet.

    Although they are indifferent to undulations in the air audible by us, they are extremely sensitive to vibrations in any solid object. When the pots containing two worms which had remained quite indifferent to the sound of the piano, were placed on this instrument, and the note C in the bass clef was struck, both instantly retreated into their burrows. After a time they emerged, and when G above the line in the treble clef was struck they again retreated. Under similar circumstances on another night one worm dashed into its burrow on a very high note being struck only once, and the other worm when C in the treble clef was struck. On these occasions the worms were not touching the sides of the pots, which stood in saucers; so that the vibrations, before reaching their bodies, had to pass from the sounding board of the piano, through the saucer, the bottom of the pot and the damp, not very compact earth on which they lay with their tails in their burrows. They often showed their sensitiveness when the pot in which they lived, or the table on which the pot stood, was accidentally and lightly struck; but they appeared less sensitive to such jars than to the vibrations of the piano; and their sensitiveness to jars varied much at different times. It has often been said that if the ground is beaten or otherwise made to tremble, worms believe that they are pursued by a mole and leave their burrows. I beat the ground in many places where worms abounded, but not one emerged. When, however, the ground is dug with a fork and is violently disturbed beneath a worm, it will often crawl quickly out of its burrow.

    The whole body of a worm is sensitive to contact. A slight puff of air from the mouth causes an instant retreat. The glass plates placed over the pots did not fit closely, and blowing through the very narrow chinks thus left, often sufficed to cause a rapid retreat. They sometimes perceived the eddies in the air caused by quickly removing the glass plates. When a worm first comes out of its burrow, it generally moves the much extended anterior extremity of its body from side to side in all directions, apparently as an organ of touch; and there is some reason to believe, as we shall see in the next chapter, that they are thus enabled to gain a general notion of the form of an object. Of all their senses that of touch, including in this term the perception of a vibration, seems much the most highly developed.”

    C. Darwin, “The Formation of Vegetable Mould, through the Action of Worms, with Observations on their Habits” (London, 1881), pp. 26-29

    1. Many thanks for this interesting information. It seems that when the hymnodist Isaac Watts wrote
           Earth from afar has heard Thy fame,
           And worms have learnt to lisp Thy name
      he didn't know what he was talking about.