Probably a little of both... with more being just their cultural situation. My neighbor is a professor and curator of herpetology at the main State University here. Herpetology is the zoological study of reptiles and amphibians. He has identified my aquatic garden's toads as Eastern American Toads, the most common in the US. He also told me that it isn't uncommon for two or even three to latch on to one another in a mating-game and actually drown one another. It is a chemical within the toad, can't remember what he called it, but I guess it is a lot like human testosterone in as much as it gets elevated and causes all sorts of behavioral mishaps for the toads. He has told me that it is not uncommon for toads to have an 85% mortality rate the first year... hence why I guess nature has them laying so many eggs. We too have had weather that went from a hard winter to a quick two weeks of summer-like, only to flash back for prolonged cold/cool spells. The toads were active during the warm spring weather and now they are quiet and haven't laid nearly the level of eggs that I'd consider "the usual." Any how, I find a few dead or drowned toads each spring... but one particularly cold morning I went out to the skimmer box for a quick leaf pull... I had 22 in there! Good luck with your toads!

I had a similar problem, both with fish and tadpoles. When it is just the fish, I have a grate that is in front of the skimmer opening. When the tadpoles showed up, I used a piece of coarse filter and wired it to the grate. It was enough to keep the majority of them out. I couldn't save them all, darn it. If you do something like this, you want to keep an eye on things blocking the water flow. I checked mine twice a day and would keep the filter cleaned out. After the tadpoles grew up, I removed the filter and left the grate only.

Is Algae-fix not on your list of 'safe' algae killers? It is actually safe for fish, but it's my understanding that all of these products have to be used with caution (and low doses) in the heat as the affect oxygen levels in the water...? I'm a pond newbie, but I have done incredibly well with Algae-Fix. It says it's safe for fountains and ponds, fish and 'wildlife.' No one has died yet, and my pond is an incredibly vibrant eco-system...koi, goldfish, hybrids, toads, toadpoles, skimmer bugs, dragonflies, birds drinking pond water all day (including the hummers, which hover at the edge of the waterfall and drink from it). So no problems so far. I also gave my parents a bottle and they use it on their three fountains. They also love it. Maybe this isn't what you had in mind? Sorry to jump right in on the thread. I usually hang in the rose forum, but I was looking for javelina advice and saw this discussion. Algae was a HUGE problem my first two springs, but since discovering the Algae-Fix I haven't had any algae at all, of any kind. Heather

It seems dunks aren't entirely safe for birds. I put a very small crumb of a donut into my fantail pigeon's bird bath to keep the mosquitos from breeding while we were on vacation. My son called us while we were in California to say the birds were dying. When we got home 8 out of our 12 pigeons were dead. Our birds also had pigeon waterers to drink from so guess not all of them drank the birdbath water. Mosquitos never get into the waterers, but I had to empty out the birdbaths every few days because of wiggletails in them. I've kept pigeons for almost 30 years and never had anything like this happen. Thought of writing to the company that makes them to inquire to see if pigeons were particularly sensitive to them, but never did. Glad to hear that apparently the amphibians are doing okay with mosquito dunks, just thought I'd pass this along.