Dear Readers, those of you who have been following the blog regularly will know that I have a great fondness for frogs – their arrival in my garden pond signals the start of spring as far as I’m concerned. That first ‘plop’ as I head out to the shed after dark is as evocative as the first crocus. I pause, looking around to see if I’ve imagined it, and if I stay still long enough, I might hear the trill of the male frog’s song. At first, the sound is almost apologetic, but as the days go on, more and more male frogs appear, until there is a veritable chorus in the shallow end.
The male frogs have largely spent the winter tucked up in a bed of dead leaves and silt at the bottom of the pond. Where the females come from is a little more uncertain. To start with, it’s a bachelor party, but this year, after a few days of gradually rising male frog numbers, I saw one female sitting on a flat stone, while twenty tiny frog heads gazed up at her adoringly.
‘Don’t go in the water, girl’, I muttered as I past by on my way to top up the bird feeders.
But lust will have its way, and not an hour later I peered into the pond to see a large female frog with a male clasped to her back, tumbling over and over in the water while several other males tried to get in on the action. It’s no fun being the first female in the pond, for sure.
Then, I spotted a female with a single male riding on her back. The pair of them were sitting under the lilac bush, unperturbed. What to do? Were they lost, or was the female just seeking a break from all the action? They were certainly vulnerable to cats and, after dark, to the foxes. I picked them up and was, as always, surprised by the strength of those muscular legs as they tried to kick their way to freedom. I gently lobbed them both back into the pond. I hope the female frog will forgive me.
And so the frog breeding season was going along merrily until the temperature plummeted. We had a week of the coldest temperatures that I remember since I moved to East Finchley eight years ago. The pond froze solid. Every day I broke the ice, every day it had frozen again within a couple of hours. My only consolation was that no one had actually produced any frogspawn yet. When I broke the ice I would occasionally see a completely torpid frog at the bottom of the pond. When the temperature goes below freezing amphibians often go into stasis.
When the weather broke, it took a few days for the frogs to revive, and then they came back with great enthusiasm. More and more frogs came to the party. They started to lay great quantities of frogspawn in the shallower parts of the pond. One favourite area was on top of some reeds that I’d cut back – maybe the prickly stems afford the eggs some protection. Once frogspawn is laid, the other frogs seem to take a shine to the same area – maybe if there are thousands of tadpoles in one place, it increases the chances of ‘your’ youngsters being missed in the case of predation. Oh, everything was going swimmingly (sorry)!
And then, the temperatures plummeted again, and we got another bout of snow. What to do this time?
Froglife, the UK amphibian charity, had an emergency post on its website, stating that any spawn laid above the water line would be vulnerable to ‘winterkill’ if it froze. The advice was to take the spawn and put it into an unheated shed or similar for the duration of the coldspell. The problem was the location of the frogspawn in my case – it was so entangled with the reeds that it would have been impossible to remove it.
And then I came up with what I hoped would be a solution.
My birdfood comes in some very irritating, unrecyclable plastic buckets, which I’ve been storing for some unspecified future use. Their moment had arrived! I plonked the buckets over the piles of frogspawn that I could see, immersing the lip of the bucket below the water line. My hope was that even if the surrounding water froze, there would be a small temperature difference which would prevent the frogspawn from freezing.
On the face of it, it seems to have worked. Today, the frogs are back hard at it, and the mound of spawn is as large as I’ve ever seen it in the garden.
I wonder if there’s a maximum number of frogs that the pond will support, and if after that the population will collapse? A few years ago we had ‘the great frog massacre’, in which piles of dead frogs were left by the side of the pond, but so far this year I’ve only seen one poor deceased amphibian. This is very lucky, as judging by the fox footprints all over the frozen pond last week, we have frequent and active vulpine visitors.
So, hopefully soon we will have tadpoles, followed by the hopping of many, many tiny feet. At the moment the pond is delightfully clear and I am preparing for my annual battle with the duckweed. The duckweed nearly always wins, but I intend to hold it off as long as possible.
We owe so much to frogs. Who knows how many millions of these creatures have been used as subjects in school biology labs and university science projects? And yet, when I spend a bit of time beside the pond it becomes obvious that each frog has a different character – some are bold, some are shy, some are aggressive, some are quick to withdraw from a fight. They are resilient, driven creatures, and even two bouts of sub-zero temperatures haven’t dampened their enthusiasm to pass on their genes to the next generation. And in my garden, no one will pull them from the water and experiment on them for the sake of getting a grade in an examination. I had never really thought of a garden pond as a sanctuary, but I suppose in a way it is.
Now I just need to get the pond declared a Site of Special Scientific Interest so that I can protect it in perpetuity :-).