Totally taken over by tadpoles (well, almost)

Dipping tray yesterday (14 May 2010): click for a closer view

I thought it was about time to dip the Old Pond to see how things are  going.

And its pretty clear that there are a lot of tadpoles – mostly rather small and growing rather slowly.

But lurking amongst the bucketloads of taddies I’m pleased to see:

  • quite  lot of caddis flies – there are two kinds: the group known as the Cinnamon Sedges, and the swimming caddises known as Black Silverhorns (Mystacides azurea).
  • plenty of Broad-bodied Chasers lurking amongst the moss (a couple can be seen in the photo – one nearly ready to emerge and one half grown) and Large Red Damselfly larvae (also in the pic) – and now we’ve had our first adult Large Red’s emerging as well
  • plenty of my nice little Smooth Rams-horn snails.

But what was most interesting were some tiny darter dragonfly larvae – presumably quite recently hatched – probably Common Darters (Sympetrum striolatum)

So this means that the pond has more species of dragonfly than the average damaged countryside pond – though not more than an unpolluted countryside pond.

One difference between this year and last is I’m very short of Pond Olive mayfly larvae – this time last year there were hundreds but, perhaps because of competition with the tadpoles for food, they are much less common now. In fact after quite a bit of looking I haven’t found any yet.

Considering the abundance of food (tadpoles) there aren’t many backswimmers or beetles around to capitalise on the potential feast. Newts would have a field day, too, but so far we’re newtless.

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5 Responses to “Totally taken over by tadpoles (well, almost)”

  1. Beryl Says:

    Do tadpoles grow at different rates dependent on availablity of food? Ours always seem very slow compared to others seen elswhere on our travels.

  2. Jeremy Biggs Says:

    Hi Beryl

    Yes, tadpole growth rates do depend on the availability of food – and also on crowding (more taddies, slower growth) and temperature (warmer water, faster growth).

    Most interestingly, all other things being equal, Common Frog tadpoles from areas where ponds are temporary grow faster than those where ponds are permanent. The temporary pond taddies are genetically programmed to grow faster.

    Jeremy

  3. Judith Says:

    My tadpoles are all in 3 separate ponds of their own to give them a chance of growing up to be frogs as there wasn’t enough vegetation in the main pond (relined this year) to protect them from being eaten by my 30-40 newts.
    They are all of different sizes from quite large to no bigger than when they first began swimming free from the spawn.
    I had read that the bigger ones release something into the water to inhibit the growth of the others so only the strongest develop fully this year. Is this true?
    The very biggest (from the same batch of spawn) are those that somehow avoided the newts and survived in the main pond.
    Reading back on the blog – I too have loads of Caddisfly larvae trundling along the mud. Mine are Leptocerus (or Leptocella?) aterrimus and they move surprisingly fast.

  4. Diana Says:

    We’ve been away for over three weeks and before we left there were hundreds of tadpoles and I had seen just one or two of the great diving beetle larvae. Now, there are hardly any tadpoles, difficult to assess as some are no doubt hiding round the pond. I have seen perhaps half a dozen beetle larvae, some quite large, since we have been back so it must have been mayhem whilst we were away, or else the cold weather killed off the tadpoles – is that likely?

    • Jeremy Biggs Says:

      Hi Diana

      I think diving beetles are the more likely cause of the tadpole’s demise than cold – cold weather alone shouldn’t kill the taddies.

      Jeremy

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