So just how many green grubs fit inside a standard Japanese Tree Frog anyway?
Well, judging by what we saw in the garden recently, the answer to that question is; at least four. Or four and a half if we count to the brim!
An impressive effort for something only slightly larger than a thumbnail!
Meet Hyla japonica, the cute little frog which is endemic to Japan and hugely abundant at this time of year. They are known locally as “ama gaeru” (lit: rain frog) due to the males’ loud and constant mating choruses before and after rain. Individuals are only 12-35mm in length, but they are certainly not shy in announcing their presence if there is a mate to be found.
Despite reports of diminishing frog populations across the world, these guys report to rice paddies and home gardens in cavalries during warmer months. They eat only live prey diets consisting of mainly insects, small fish, spiders and … grubs!
Being free roaming frogs, they do not require water close-by for survival. That said, they are very common on the edges of lakes and rivers, as well as around flooded rice paddies in rural areas. They also live in trees and bamboo stands; or amongst grasses, or in the soil. They can survive extended periods without water, even during very cool, dry periods in late Winter.
At various times during the year, it is common to see 10 to 20 individuals within only a few steps in our garden. A stroll along grassed rice paddy banks will also reveal the leaping hoards who usually sit patiently waiting for food to pass by.
Although nothing as poisonous as the South and Central American Poison Dart Frogs from the Dendrobatidae family, Japanese Tree frogs do have mild toxins within their skin for protection against predators and disease.
Despite this, they can be handled relatively safety without too much of a problem. Be sure to wash hands after handling any specimens and do not allow the slime from within the frogs’ skin to get in the mouth or into open cuts and wounds.
And as a final safety precaution, don’t stick frogs in your eyes… the slime causes pain and permanent blindness.
The frogs are able to change their colors from a bright green, through to tones of gray or brown depending on their surrounds. The brown coloring in specimens is usually found during the drier, cooler months when greenery is yet to flourish.
This tiny guy has recently gained extra attention for itself due to work carried out by Polytechnic University of Catalonia in Spain. The scientists studied the frog’s communication methods and one observation from studies was that the females are quite poor at distinguishing synchronized male mating calls from one another. In other words, the ladies can’t hear the guys when they all speak at once.
However, to overcome this problem, it appears the crafty males have developed an extraordinary ability to precisely de-synchronize and specifically separate their grrp, grrp, grrping within the crowded airwaves.
Engineers have modeled the specific communication techniques and will use the “de-centralized, de-synchronization” methods to improve signaling algorithms and to help decongest Wi-Fi networks.
So there you have it.
A tiny green frog which offers natural pest control in gardens by stuffing itself full of grubs, while also offering clues to breakthroughs in cutting edge Wi-Fi technology. Quite a little champion species!
For more information on the specifics of the Wi-Fi modeling research mentioned, see: Hugo Hernández y Christian Blum. “Distributed Graph Coloring: An Approach Based on the Calling Behavior of Japanese Tree Frogs”. Swarm Intelligence 6 (2): 117-150, 2012. Doi: 10.1007/s11721-012-0067-2