Amazon Poison Dartfrog (Ranitomeya ventrimaculata)

Amazon Poison Dartfrog or Reticulated Poison Frog (Ranitomeya ventrimaculata, formerly Dendrobates ventrimaculata, originally Dendrobates minutus ventrimaculata), Bauchflecken-Baumsteiger, Explornapo Canopy Walkway, Rio Napo rainforest area, Loreto, Peru


Very complicated and sometimes conflicting taxonomy of this very little beauty (15-20 mm!!!). They were found at the inflows of the Amazon River in Peru, Ecuador, Colombia and Brasil and another occurence would be in French Guyana.


They are one of the species that live not on the ground of the rainforest but high up in the trees. In this case it was about 30 m above the ground. Usually and most of the time they live in and around a bromeliad.


Unfortunately poor quality shot. However, I took this with my big lense (400 mm) and hand-held. There was no time to fumble around with a tripod, the frogs were running quickly up the tree. That's best I could manage with PS.


Please, look through the whole comment section, there are some other images...


Interesting facts:

Let's talk about the reproduction and developement of the little dartfrogs in the rainforest. The adult frogs will check if the bromelia is already occupied by another tadpole, own one or different ones. Usually there is not enough food for more than one tadpole in this miniature pond within the bromelia. It will feed the little algae from the walls of the funnel. So the parents will put their eggs in different tank bromeliads to ensure there will be enough food for one. Astonishingly, if there is already a tadpole in the bromeliad, this tadpole can "alert" the frog: Already occupied. The developement will last quite a longtime under these "unfavorable" conditions. Remember: There are no other nutrition nor minerales in this environment. From time to time, the female may lay some other eggs in the funnel to feed the tadpole with its "own" eggs. These very intensive and resource consuming parental care under difficult conditions will succeed in survival of the individuum. But a few questions arise: Why is it specially in the neotropics around the Amazon River often the case that many of these species will avoid the water for breeding. I will focus on these question later in other posts.


Another interesting story is diversity and variability versus frequency of these species. Let's make some comparison with the amphibians in Central Europe. In the eastern Peruvian rainforest scientists had found about 40 different species per 1 qkm. In Europe there were about 12 different species found on 1 million (!) qkm, meaning about 10% of the species amount in the rainforest of Peru. But the weight of one Marsh Frog (Pelophylax ridibundus), which is the largest frog in Central Europe, is about 100 times the weight of a little dartfrog. So compared to the rainforest wildlife around a garden or forest pond is much more abundant than the wildlife in the rainforest. However, there is only 1 or 3 different species around where as in the rainforest you will find on the same area up to 20 to 30 different species. But you will never see such an extremely mass of frogs and toads in the rainforest as you may see in the outer tropic regions. Enemy pressure and food resources are all the time key issues for survival of a species. In the outer tropics nature will do this by masses of spawn in the rainforest it is a sophisticated and intense parental care. Nature will not have any other choice: There are unfavorable conditions and low availabilty of food resources in the rainforest.

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Taken on March 13, 2011