March 2004 and Frog Spawn Pond Watch.
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Well they say that March comes in like a lion and out like a lamb and it's certainly true this year. This was the scene on the 12th March, which was the date that we had the frogspawn two years ago that I follow growing indoors on the March 2002 page. But nature has an amazing way of laying dormant and then starting up the minute that it's warm enough.
I was wondering if the frogs were ever going to come but four days later, on March 16th, it was really nice, sunny, warm and springlike; and hey presto lots of frogs in the pond getting up to lots of naughty froggy behaviour!! Since my frog spawn pages of two years ago proved so popular I'm going to attempt to show the frog spawn developing in the pond this year. More difficult than in a tank but it should make a good comparison. If you want to look at frog spawn growing indoors then start at the March 2002 page.
When I first went over to the pond all of the frogs swam away but if I just sat by the pond they seemed to get used to be and came back. The air is alive with the plaintive croaking of frogs that haven't found a mate yet. But there are already lots of pairs and quite a lot of frog spawn. If you look at the photo above you can see that the newer frog span is much more dense and it expands in the hours after being laid, otherwise it wouldn't fit into the female frog!
Some of the spawn must have been there a little while as where it is warm on top of the water it has started to develop. Look carefully at the photo below and you can see that the cental embryo has started to divide in two.
The weather got pretty foul after a couple of days (although nothing like the picture above!) and all of the frogs just dissapeared as abruptly as they arrived. I seem to remember the mating going on for much longer last year, and possibly there was more spawn. It may be that the very dry summer last year wasn't good for the frog population. Certainly, despite the fact that there was a lot more spawn last year than the year before, we didn't get quite such a plague of frogs exodus of baby frogs.
Interestingly though, there were still some tadpoles in the pond right into the autumn. I have heard that sometimes tadpoles do overwinter. When I was weeding this morning (March 21st) I found a tiny froglet. I'm not sure if he was a result of one of those late tadpoles but you would expect last years tadpoles to be fully grown and breeding by now. I found this on a wildlife trust site but nothing about what causes it to happen:
Some tadpoles have been known to overwinter in ponds as tadpoles and then be ahead of the game in spring. It seems it might be advantageous to remain as a tadpole rather than trying to overwinter as a small frog!
I have a theory that it might have been due to the very hot summer last year - maybe very hot summers cause such a high mortality rate that it is a survival trait to have some of the tadpoles wait until the following spring to mature? Still no sign of any toadspawn which I was hoping for. That said there's quite a bit of duckweed on the pond so it is possible that I might not see it if there was some.
Due to a combination of the dull weather and the enthusiastic duck weed growth on the pond, it is proving quite a challenge to get good pictures of the spawn developing. Here it is 12 days later, on the 28th March. It has developed a good way and I would expect to see the tadpoles start moving any time now. The pond itself has gone quite green and many of the plants are starting to grow.
Finally, on the 30th March, a nice sunny spring day and I finally got some pictures of the frogspawn at a fortnight. I haven't actually seen any of the little tadpoles moving yet but at this stage of development I would think that they are. If the warm weather stays we should get it hatching pretty soon.
Proper little tadpoles still inside the spawn.
And finally just a picture to compare with the beginning of the month. Not a huge amount of greenery yet but it will soon take off. March is going out like a lamb after all!!
The frogspawn has now hatched on the April 2004 page
Do you like this page? Is it useful? Please email me and let me know. I get a lot of spam so put something about tadpoles in the title so I can spot people's emails!! I always say that you can tell that it's spring when the frogspawn emails start to arrive, but I'm always interested in hearing about people's experiences.