Exposing frogs, toads and salamanders to an artificial “rainy season” is hands down the surest method of encouraging captive breeding in most species. Fortunately, even someone with my limited building skills can easily construct a simple rain chamber.
Timing and Temperature
Before placing potential breeders into a rain chamber, it is important to research the species’ natural history, as timing, temperature and other factors are important considerations. For example, Smoky Jungle Frogs (Leptodactylus pentadactylus) and certain other tropical Anurans have surprised me by breeding at nearly any time of the year, and without temperature manipulations, but Wood Frogs (Rana sylvatica), Marbled Salamanders (Ambystoma opacum) and other temperate zone amphibians need a cooling-off period beforehand.
Opportunistic breeders dwelling in habitats subjected to droughts, such as Colorado River Toads (Bufo alvarius) and Spadefoot Toads (Scaphiopus spp.) sometimes begin calling when I dump extra water into their enclosures! On the other hand, White’s Treefrogs (Litoria caerulea) reproduce most reliably when exposed to conditions that are both dry and cool before the “rains” set in.
Water temperature can be critical as well – usually rain brings a drop in temperature, but warm rains will of course do the opposite.
Building the Rain Chamber
Attach the perforated flexible tubing to the pump’s outflow and run the tubing up the side of the aquarium. Using cable ties, attach the tubing to a screen aquarium cover; run 3-4 parallel rows of the tubing across the entire cover to ensure wide dispersal of the “rain”.
You can set a timer to allow for intermittent showers throughout the day and night, or simply run the rain system overnight – both strategies seem to work equally well.
The water within the rain chamber should not be so deep as to force the animals to be continually swimming – this is particularly important for terrestrial species such as Horned Frogs (Ceratophrys spp.) and Fire Salamanders (Salamandra salamandra). Be sure to add floating live or plastic plants as well, so that the animals can rest. Depending upon the species, a platform or piece of cork bark might be needed as well.
The Zoo Med Canister Filter comes equipped with a spray bar…I’ve not yet tried, but since the filter can be operated with a very low water level it should make for an easy-to-install rain chamber.
Some folks have reported that exposing Red-Eyed Treefrogs (Agalychnis callidryas) to Misters and Foggers is sufficient to induce reproduction. This is certainly worth trying on other tropical frogs as well.
Please see my article Breeding White’s and White-Lipped Treefrogs for specific info on these popular amphibians.
Check out this video of Wood Frogs at a breeding pond – if you don’t keep these interesting little guys, by all means try to observe them outdoors (they are one of the first spring breeders in the NE USA, often beginning by mid-March).
Frog in frogspawn image referenced from wikipedia and originally posted by Salimfadhley