Today is Wednesday you know what that means? Another frog post, today we are looking at the continent of Batrachia, the second largest continent and home to two frogs, Dendrobates spp. and Phyllomedusa bicolor.
Batrachia
Batrachia is, as mentioned above the second largest continent and also the middle continent, in between Bufia and Incilia. It is quite dry evem though warm equatorial currents hit its East side, that is due to the mountain chain present here that even though it is not so high, it causes some Rainshadow effect what leaves the interior of the continent dry, with the predominant biomes being that of savanna, steppe, xeric shrubland and arid desert. While there are some forests in areas that encounter warm currents such as the rainforests of the East coast, mediterranean climates from the tips of the continent, the Western and Northern temperate forests.
The leaf frogs(Phyllomedusa spp.)
Cannibal giant leaf frog(P. gigas)
This phyllomedusid is slightly larger than their ancestral, however their key difference is not physical but behaviorial. These frogs are very active and aggressive, hunting ivertebrates but principally other frogs including their own species such as the males, who are smaller than females. Other than this predacious behaviour no other customs have chnaged much.
Diver giant leaf frog(P. hydrica)
This and the following species have changed behaviorally in quite a drastic way... The Diver giant leaf frog descended from the trees onto the many rainforest's rivers, evolving adaptations for their new life as semi-aquatic predators. Webbed feet is such an adaptation, being used for better underwater propulsion. Another adaptation for a semi-aquatic life-style is not physical but as all other species from this genus, behaviorial. For this new way of living these frogs, as mentioned before have forgone climbing trees and live mostly near water, coming to land from time to time. As they live close to the water they don't have the need of laying eggs in leaves above water, instead laying eggs directly onto the water with a foam-nest for protection of the eggs.
Ground giant leaf frog(P. grada)
The last but not less important species, the Ground giant leaf frog exploits a niche that the other frogs on the continent don't, large terrestrial frogs. This niche isn't occupied by any other frog as the poison dart frogs are not large enough to compete with the Giant leaf frogs and so this niche was free to be taken. Thus this frog predates upon many animals on the soil including other frogs. Their egg-laying behaviour is somewhat a mix of both previous species, being able to lay eggs above water, hanging on leafs glued together and underwater too, among plants and protected by a "foam".
The new dendrobates(Dendrobates spp.)
Dendrobates spp. is a genus of small frogs native to the Amazon rainforest well known for having their potent poison being used by indigenous people in their blowdarts, which has led to this genus being commonly called as Poison dart frogs. They get their characteristic poison from the invertebrates they consume, what exactly is unknown but it is suggested that some mites and other invertebrates. This selective feeding of only these toxic animals is, added to their diminute size a problem that this genus encountered when adaptive radiating into new species. Yet they suceeded and here are some of the new species from this genus.
Leaf poison dart frogs(D. saltatorius)
The first species we take a look at is known as Leaf poison dart frogs, this is due to their green coloration that somewhat resembles a leaf. They have pactically doubled in size compared to their ancestral species, D. auratus which had an average of between 2-3 centimeters in Snout-to-vent lenght. This comparatively larger size is due to both the great lack of predators and for better locomotion, as their small size grants small jumps, which are not great in an arboreal environment that demands changing from tree to tree in order to reach new hunting grounds. Eggs of this species are laid inside of small water pools formed in the "cups" of bromeliads, where the tadpoles will feed on algae and mosquito larvae, plus any other small animal that may find itself in the pools.
Dead leaf poison dart frog(D. terrestris)
In the same way the Leaf poison dart frog is inconspicuous when sitting on leafs the Dead leaf poison dart frog becomes camouflaged among dead leafs in the ground. They are the descendants of D. leucomelas that-as all other new dendrobatids- doubled in size due to relative lack of predators. These brown-colored frogs live in social groups-which is quite unusual for frogs. Such armies are comprised of 6-10 individuals and will fight with other armies over territory. This species can be found on the monsoon forests that are the frontier between rainforest and savanna, in such locations the frogs aestivate to avoid the summer heat.
Common poison dart frog(D. vulgaris)
Both D. terrestris and D. vulgaris are found primarily on the ground, with the latter being less widespread compared to the former even though it receives the name of Common poison dart frog. This species is one of the least changed, both behaviorially and physically, with the most noticeable change being their size.
Water poison dart frog(D. hydricus)
The last frog species we will see today. Descendant from the subspecies D. tinctorius azureus they sport generally a blue coloration used in camouflage underwater as they are the only semi-aquatic species of the genus. They show Countershading, having a dark blue on their backs and lighter tones on the belly and limbs. These Poison dart frogs are the least toxic as they dont feed so much on their previous prey, now foraging underwater and near the water's edge. Curiously this species has tadpoles that can endure slightly brackish waters, and larvae populations that live near the ocean display the behaviour of swimming downstream into brackish waters when evading predators. Though the larvae can resist salt levels in the water of up to 1225 ppm(parts per million) the adults cannot outstand that much salt around them.
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