Goings On in the Pond

Male frog waiting for the females to arrive

Male frog waiting for the females to arrive

A week ago, as I headed out to the shed, I heard the smallest of croaks coming from the pond. Just a single ‘ribbit’ and then silence. But that little sound was as much a harbinger of spring as all the crocuses erupting into flower. For it meant that the frogs were waking up.

At first, the males appear. They are smaller than the females, and have spent all winter in the silt at the bottom of the pond. They can breathe through their skin if they are not very active, but as the days lengthen and the temperature increases, they need to come to the surface to breathe. The second sign of spring is the increased interest that the local cats show in the pond. All winter they’ve ignored it, but now they can sit and stare at it for hours. Jarvis is a newcomer: a very fine cat and (fortunately) not one to get his paws wet if he can help it.

Jarvis waiting to play Whack a Frog

Jarvis pretending that he isn’t interested in the frogs. Not at all.

The males are hyped-up. Their hormones start to change in the autumn, so that they are ready for action the instant the weather gets warm enough. While they are waiting, they sing to attract the females, and sometimes attempt to mate with other males. The males make a very particular grunting noise if propositioned in this way, the frog equivalent of ‘try that again and I’ll wallop you’. Once the female has laid her eggs, she will make exactly the same sound if a male tries to grab her again.

Male frog hanging around

Male frog hanging around

Eventually the females turn up – in my garden, females arrived within a day of the males’ serenade. They seem to be able to find their way back to their natal pond by smell, as the combination of the particular plants that grow there seems to be unique for each water body. Once the females arrive, there is a thrashing, roiling orgy of froggy copulation. The males hang on to the females, clasping their front feet together under her armpits in a grasp called ‘amplexus’. This can last for anything from a few hours to several days. Even capturing the frogs for a quick attempt at a picture is not enough to put them off their stride.

Two frogs in amplexus, refusing to be separated even when the paparazzi arrive

Two frogs in amplexus, refusing to be separated even when the paparazzi arrive

The purpose of all of this is so that when the female lays her eggs, the male can fertilize them right away, without any other male getting a chance to do the same. Female frogs are very swollen prior to egg-laying, and look a little saggy afterwards, and no wonder – the mass of eggs being ejected is enormous for such a small animal.

Frogs mating at the edge of a mass of frogspawn

Frogs mating at the edge of a mass of frogspawn

In my pond, the frogs have chosen to lay all of their eggs in the shallow end, where the water barely covers the pebbles. The sun warms the eggs, and hastens the development of the tadpoles inside. Each clump of frogspawn represents one mating, and can contain between a thousand and four thousand eggs.

Frogspawn so far

Frogspawn so far

Frogs are invaluable for the garden. Up to twenty-five percent of their diet is snails and slugs, with caterpillars, gnats, and other insects making up the rest. However, the garden is not always good for frogs. Research shows that they are extremely vulnerable to pesticides, which they both ingest by eating affected insects, and absorb through their skins, which are delicate and porous. Not only are they directly poisoned by these substances, but they also affect the immune system, making the frog more prone to fungal diseases and parasites. It seems ironic that our use of artificial pesticides is killing one of the creatures most able to help the gardener.

The Gardener's Friend

The Gardener’s Friend

6 thoughts on “Goings On in the Pond

  1. pdcrumbaker

    It will be interesting to move through the seasons with you and your garden. A wonderfully informative, interesting, witty post.

    Reply
  2. Libby Hall

    I’m enjoying your blog very much.

    My own pond, when I first made it twenty-odd years ago, was instantly colonized by toads. Many toads, dozens of toads, ‘hundreds’ of toads! I did love my toads. But over the years more and more frogs turned up and, because they are earlier and fill the pond up with their spawn before the toads even arrive, I guess the toads decided mine was no longer a pond for them. I do like the frogs – but I miss my toads. They made such a lovely birdlike sound, and were so delicate in arranging their pretty necklaces of eggs around the pond weed. (Though the males did tend to behave very badly and I often had to rescue a female from a great ball of male toads that were in danger of drowning her.)

    As I’m sure you know, the male toads also make a sound that means ‘get off me I’m another male.’ One year, long after the breeding season, I heard a toad continually making that sound. I moved away a rock from the back of which the sound was coming and there was the toad – protesting about a large snail moving across his back!

    Reply
    1. Bug Woman Post author

      Oh Libby, what lovely stories….I have never seen a toad in my garden. I keep my eyes open, but it’s all frogs, frogs, frogs. Lovely in their way, but there is something very wise about a toad.

      I am currently reading a very old New Naturalist volume called ‘The British Amphibians and Reptiles’. In it, the author, Malcolm Smith, has this to say about the relative intelligence of frogs and toads:
      ‘The Common Toad has considerably more intelligence than the Common Frog: it is generally regarded as the most intelligent of all the European amphibia. Toads quickly discover that glass is a barrier that cannot be passed, and will stop banging their noses against it. When placed on a table they will look over the edge and, seeing the drop to be taken, refuse to jump. A frog on the other hand will leap off regardless of the consequences. Its action of course is largely due to fright: in nature and when undisturbed the frog no doubt does not do such foolish things”.

      Last week I also rescued a frog that had got itself so wound up in water weed that he had a very fetching hourglass figure. On seeing me approach him with a large pair of scissors, he gave a pathetic ‘peep’ and collapsed on to his back as if dead. Once liberated he swam off as if nothing had happened. Playing dead seems like quite a good tactic for avoiding the attentions of predators.

      Finally, I have to say that, when in amplexus, the male looks as if he’s performing the Heimllich manoeuvre….

      Reply
  3. Libby Hall

    The Heimllich manoeuvre! I hadn’t thought of that. Exactly what it looks like! Heroically saving the females from choking!

    I read Malcolm Smith’s book years ago. I love his evident pleasure in the passage above in the intelligence of the toad. It reminds me of Darwin in his book about earthworms – his final book. Darwin was positively besotted with how clever the worms were – moving a leaf round to get hold of the easiest end before they pulled in down into the earth.etc … I agree with both of them – toads and earthworms and brilliant. (And Toads have gorgeous golden eyes!)

    Reply
  4. Bug Woman Post author

    I agree, Libby. Toads and earthworms are wonderful creatures. I also have a suspicion that if we look at any creature (or plant) long enough, we will discover how extraordinary they are.

    Reply

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