Hatching in Tree Frogs

Tree frogs are the most photographed frog variety, mostly owing to the unique and beautiful appearance. With green bodies, orange feet and red eyes, they are indeed striking creatures. Red-eyed tree frogs are found mostly in rainforest regions. The most interesting thing about them though is their breeding habits. Male tree frogs move towards ponds during the rainy season, where they mark and establish territory on a plant that grows near a water body. They draw the attention of females by making calling sounds and shaking trees in which they have made territory. The goal is usually to attract female mates. When it rains, egg-carrying females come to the ponds and choose mates from among the males at the pond (Boston University). The pair mates and lays their eggs, typically overnight, on plants that hang over the water body so that tadpoles can fall into the water on hatching. Eggs are usually at great risk from predators including snakes, wasps, katykids and even some forms of pathogenic fungus. The embryos could also drown if they happen to fall into the water before hatching, or die as a result of dehydration if the conditions are too dry. While the eggs are usually covered by a neural fold to protect them from the elements, it is usually not enough to serve as a detraction for predators or pathogens. Another likely trigger for early hatching is an antibiotic threat from the environment around where the eggs are laid (Boston University). All these threats contribute to the tadpole hatching before it reaches maturity or metamorphoses and falling into the water below to escape the threats present.

In order to remain safe from the host of predators that are out there targeting them, the tadpoles in the eggs have to develop some certain defense mechanism. Usually, embryos hatch early to escape when facing attacks by egg predators or under infection by pathogens. Research into the hatching of the embryos reveals that they have developed a high sensitivity to vibrations in order to escape from attacking predators. What is even more amazing about this adaptation is that the frogs are found to be sensitive to specific frequencies only, implying they can tell the frequencies of vibrations emanating from a predator attack from those caused by benign sources like wind and rain. Embryos are also able to hatch in order to prevent their suffocation, for example when submerged in water. The host of adaptive embryo behaviors make them well suited to discern threats in their general environment and react to them. The problem with these adaptations however lies in the fact that tadpoles that hatch early have a higher predisposition to dying before they reach maturity. As a result of likelihood of tadpoles hatching before reaching maturity, tadpoles are seen to enter the water at different stages of development with their ages and sizes being different. Once they are in the water below, the embryos are afforded protection from some of the threats to their existence in their previous environment. While the water provides them an additional level of security from threats, it by no way assures their safety. Tadpoles are equally likely to die as a result of threats present in the water, with tadpoles facing threats from aquatic predators like giant water bugs, dragonfly nymphs, freshwater shrimp, and most fish (Boston University). After a month or slightly more in the water, metamorphosis occurs and the tadpoles turn into froglets and their journey into maturity, and the relative safety that provides is almost complete.

Works Cited

Boston University,. ‘Red-Eyed Treefrogs » Warkentin Lab | Boston University’. Sites.bu.edu. N.p., 2015. Web. 6 Dec. 2015.