Question about late season tadpoles?

[Mr. Green Frog]

Early in the season, there were hundreds of various types/sizes of tadpoles swimming everywhere. Green frog tadpoles were the last to leave, but they often would go perfectly vertical, and skim the surface for microscopic food. So seeing them moving about was a common occurrence, then eventually pond was void of tadpoles as everyone grew legs and morphed out

About a month ago, one of the resident male green frogs had eggs turn up in his location after successfully getting a large resident female to come over. On 2nd day, I carefully scooped some into a clean 5 gallon bucket that had a small amount of pea gravel in it, and left the 5 gallon tilted on it's side and tethered with the handle weighted down into the shore with a rock, right at the shore since they were in an always sunny spot. So the 5 gallon bucket gave some sun protection acting like a canopy, but was always taking in fresh surface water and they could leave once swimming.

They soon unraveled, and swam around, mainly staying on the gravel. After about a week, any still in there were tipped out and hid under vertical pavers that were deliberately placed against other rocks, so they could attach to the undersides and avoid the sun and predators, while eating off the underside of the pavers.

Here's were it gets odd. None of the tadpoles are swimming out in the open now, like the earlier season tadpoles. It's been incredibly difficult to locate them too. I've seen a couple here and there, but it's usually by chance as sitting and scanning the bottom never reveals any movement. One I saw yesterday, was in a shallow end and an OK size (body slightly rounder than a pencil eraser) and it looked developmentally normal, but it was staying on the small gravel, moving only occasionally.

Early season when I think most of the 1st eggs were developed, water wasn't clear and think pump wasn't running yet. So water would have been left over snow melt and rain. Pump was started, and left to recirculate at the water's surface, which helped the water clear up a bit. So those tadpoles mostly had the murky water that'd only clear after a week or so with no rain. Added 55 gallon filtering system about a month ago, so water is basically always clear unless heavy rain, which is clear again usually within a day.

So is the clear water possibly causing them to be more reclusive? Or do they stay hidden until a larger size and didn't realize the previous ones were probably older by the time they were spotted?

 

[addy1]

Mine hide, if the water is clear. They love murk. They dive into any thing that hides them.

 

[Mr. Green Frog]

Mine hide, if the water is clear. They love murk. They dive into any thing that hides them.

At one point do you notice they start coming up? A couple months old?

I'm interested in seeing how many might have survived from that singular egg laying event. And also curious if these guys will be forced to overwinter in the pond, or if they'll make the cut-off to leave before winter arrives.

 

[BKHpondcritters]

Mine hide, if the water is clear. They love murk. They dive into any thing that hides them.

Yeah, mine hide the vast majority of the time. I almost never see tadpoles of any type other than the toads down in the main pond. (when the toad tadpoles are here, they are pretty much everywhere, on every single flat rock & surface all around the pond & shelves, both in the main pond & upper pool) I will occasionally see a frog tadpole hiding on one of the shelves in/under plant foliage, but I need to go poking around & looking for them. They don't come out voluntarily. I do occasionally have a medium to large tadpole turn up in a skimmer basket when I go to empty it, so those are just plopped back in somewhere & they immediately disappear from sight.
Now, in the shallow (4 - 6" deep) upper pool area, frog tadpoles are a more common sight, but they do quickly swim under whatever cover they can find when I approach. Earlier in the year before the plants take over up there, they might take cover in some 'muck' or algae on the bottom. Now, the plants are so totally overgrown there's very little open area to see anyone. Again, I do catch them sitting on the gravel in the small areas of open water, but they tend to scoot out of sight almost immediately if they notice me.

 

[Mr. Green Frog]

That's very interesting! Being new to this in general, I assumed the early year behavior was the norm, but after hearing your own tadpole behavior, guess not. Maybe they were liberated by the more opaque water then. And given there was like hundreds of various tadpole species, maybe it forced them to be more competitive with getting food or something. They never seemed to notice me or react either.

 

[addy1]

At one point do you notice they start coming up? A couple months old?

I only see them if I disturb the area, then they bail for a new area. When they first grow from eggs to tads I see a lot more than they slowly start hiding and or get eaten.

 

[Mr. Green Frog]

Hmm. So curious to see how many from that single egg laying event are actually still alive then. Hopefully they start to rise and skim the water surface.