Monday 20 March 2023

Some Frogs Did A Courting Go -17th March 2023

Each year Common Frogs, often travelling some distance, make their way from wherever they have been spending the year hidden from their many predators, to a series of small, shallow ponds in The Lye Valley, a narrow strip of endangered fenland that is now a reserve, surrounded on all sides by urban habitation and situated on the eastern fringe of Oxford. The reserve is lovingly tended by volunteers and the presence of the frogs is well known to both local residents and folk such as me who desire to come and tarry on the narrow boardwalk that runs through the valley to watch the frogs during the very brief time they are present.

The ponds are very close to the boardwalk but the frogs are heedless of anything but the business of courting and in the case of the males finding a female to cling onto. Once attached to a female's back, who incidentally selects her partner by the quality of his croak, little can detach him as he clings on with grim determination. Other male frogs will try their utmost to dislodge him but rarely if ever succeed. When the female chooses to release her eggs (spawn) the male fertilises them as she ejects the eggs.

The average date for the frogs to return to spawn in The Lye Valley is the 21st February but this year there was no sign of them. Almost three weeks elapsed and people were becoming concerned. I had already made two abortive trips to see if they had arrived. Where were they? It was presumed the cold weather had delayed the frogs arrival but finally frogs and spawn were spotted in one of the ponds on the 12th March and it was game on. 

With other commitments during the week I arranged to meet Peter on the boardwalk at 1030 on Friday the 17th in the knowledge the frogs had been in full spawning swing the day before and sure enough we found them hard at it but the numbers were smaller than usual with only between twenty to thirty present.

We stood and watched them as they lay in the water, plump bodies supported by the weed, their heads and goggle eyes protruding above the surface. This is perhaps the only time one can get to see frogs so close and relatively in the open.The process of spawning is a dangerous time for the frogs as they are exposed and vulnerable so the period of spawning is completed as rapidly as possible so the frogs can retreat back to the security of the surrounding cover.

To say it was a scene of frenetic activity would be an exaggeration as the frogs do not operate in such a manner.They prefer to float in the water or amongst the spawn, motionless, front legs bowed inwards and then make a sudden move before lapsing into immobility once again.What motivates them to move I do not know but presumably there is a surfeit of male frogs and when a female appears, with or without a mate on her back they make their move. This can result in a guddle of legs and bodies as up to five male frogs move around a female in the water. All are rejected if the female already has a mate attached.

All the while a discrete croaking from the males accompanies proceedings, a soft sound like a distant motorbike, their flaccid white throats swelling and distending before deflating like someone blowing bubblegum. Today the croaking was particulary subdued possibly because there was little incentive due to a lack of available females. Other  frogs lay in the weed. separated from the centre of activity, seemingly disinterested in proceedings or spent, while others would half heartedly try to dislodge a rival from a female's back but with no real conviction or success.

I had a sense the spawning was coming to a conclusion and so it proved as the next day not a frog was to be seen, the only evidence of their presence was the jelly like spawn floating in the shallow water.

And so it will be another year to wait until, once more, I go to welcome the frogs back to The Lye Valley.

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