Nearly all Tadpoles Hatched
The weather over the last week or so has been unsettled, but fortunately we have not had any snow showers, just rain and sunny intervals. The majority of the tadpoles have now hatched, although there are still several still within their transparent egg cases, but these are very active and we suspect that the remainder of the tadpoles will hatch in the next few days.
The first hatch-lings emerged from the spawn that was in the middle and at the very top. These animals hatched first perhaps due to the fact that the being at the top they received most sunlight and therefore were kept warmer, being in the middle of the spawn may have helped keep these embryos insulated and therefore protected better as the surface water cooled in the chilly nights.
By Thursday of this week some of the first hatched tadpoles had left the spawn and could be seen hanging vertically from pond weed and the fine fronds of algae, one of our team members remarked that they looked like little music notes hanging from the staves on a score sheet. By today, Sunday, a number of tadpoles have made the break from the spawn and are seeking shelter amongst the pond weed. This might be as the yolk that nourished them once they had emerged, (the slightly brown bulge in the belly of the tadpole), has now been used up and the tadpoles are beginning to seek their own food. Their black colouring whilst being effective in helping to absorb heat, does not provide them with a lot of camouflage in amongst the green Elodea.
Most of the Tadpoles have now Hatched
Picture Credit: Everything Dinosaur
The pictures shows that the majority of the Tadpoles have now hatched. They remain congregated around the spawn, especially on top of it where it is warmest. Over the next few days it is likely that the tadpoles will disperse throughout the pond.
We noticed that during daylight hours the “clump” of hatched tadpoles spread out to form a rough doughnut shape, then as it grew darker and presumably colder the tadpoles seemed to gather together again, concentrating as a mass on top of the spawn again. Whether this is an instinctive response to less daylight in order to keep warm so as to survive the colder night; or whether this is a strategy to avoid predation is unclear.
One adult frog has been spotted in the pond this week, the small adult male. He has kept a low profile staying on the periphery of the pond away from the hatching tadpoles. He has preferred to remain in cracks on crevices around the pond’s edge during daylight hours.