In early spring, in a puddle near my home, I saw what appeared to be frog spawn. I knew these eggs would eventually turn into tadpoles. So I returned every couple of days until they hatched. My goal was to watch them grow. I thought it would be fun.
Here are the eggs. I didn't want eggs so I just observed them. I first noticed them in early to mid-March. Given the season, it was easy to identify the suspect frogs. I didn't see any adults around, but I think they were the Korean brown frog, Rana coreana [한국산개구리]. I've found a lot of them around in the years before.
Eventually, the eggs hatched into tadpoles, so I gathered some. Normally, I don't like messing with nature, but I figured, the puddle would dry up and they would all die or most of them would be eaten by predators. I know what I'm doing and figured I could increase the odds in their favor.
I made them a habitat on my screened-in balcony. I had collected some of the water while they were eggs and I filtered that and allowed a couple of weeks for algae to grow. I even added some other stuff to help with the nitrogen cycle. I had a filter in there as well, but after moving in the baby tadpoles, I removed it for a week to let them settle.
I was still visiting there home to get water and food for the guys. I fed them fish food as well, but natural food and water is best. Actually, their friends were doing okay, but the puddle was really starting to shrink. I wasn't too worried because it was possible for them to swim to a deeper part of the puddle, but they liked hanging around in the shallow corner.
The pollywogs I had taken home had really started to grow. I think they were growing a little faster than their buddies outside, but I'm not sure.
Also, at this point, I realized I had about 100. I decided I couldn't raise this many because it would be difficult. So, I returned a few. I also installed a filter because they were getting bigger and really starting to eat a lot.
If you wonder what I fed them, it was mostly boiled cabbage and pond scum (algae). They also ate some sinking fish food pellets I have for my shrimp.
I returned about 50 the first time, then I returned another 25 shortly after. When they start changing from the larval (tadpole) stage to the froglet stage, they eat a lot. The water was also smelling. I keep aquariums at home and they are always pristine, but keeping water clean for tadpoles is almost impossible. They grow really fast and eat a lot.
The puddle I was returning them to was still there, fortunately. By this point, there were tens of thousands of tadpoles in the puddle. Actually, we had a wetter than average spring, so the puddle never dried up.
Also, it seems like the birds and the cats didn't find these guys. Maybe because of its location. There were too many trees for the herons and egrets to get there (these guys will eat hundreds an hour). And the ground was a little swampy so this will keep out all but the most determined cats. Also, the tadpoles had a deep corner to go hide in.
Here was my final habitat. At this point, I only had about 15 of them left. Surprisingly I didn't have any die on me, so I definitely helped them out a lot.
This was also the stage when they had back legs and were starting to grow front legs. Soon they would be frogs and they would be jumping about and breathing mostly air.
I didn't actually want to keep them at the frog stage for long because feeding them is difficult. I had some food they would eat, but by this point, it was time to say goodbye. I put them all back where I found them.
I imaging we are going to have a lot of frogs this year. I can already hear the tree frogs now and I have seen quite a few. Maybe I'll go out looking for some tonight. Who knows, the tree frogs should start breeding in the rice fields soon and if I find some, I'll probably be tempted to rase them, too!