Frogs Use Math to Make Themselves Heard

green and orange tree frog on green plant

Biological Strategy

Japanese tree frog

AskNature Team

Image: Matt Houghton / Unsplash / Free non-commercial use

Navigate Through Air

Although free from many of the physical obstructions found on land and in water, organisms that move through the air must still avoid hitting each other and objects in their flight path, such as trees and mountains. They also need to navigate from one place to another, which presents a different challenge. They use one strategy to navigate around obstructions and another to move towards their destination. For example, bats use echolocation to detect both obstacles and prey. To navigate during migration, bats also use vision, sun orientation, and likely other strategies.

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Differentiate Signal From Noise

The environment surrounding any living system is full of signals, such as smells, sounds, electricity, magnetism, and more. Too many signals at once can be overwhelming, making it difficult to locate and react to any particular signal. To address this, living systems must differentiate among all signals, or “noise,” so they can focus on those they really need. During mating season, for example, male frogs gather close together in large groups to call for females. Despite their overwhelming, collective noise, females are able to find a particular male whose call is attractive to her. This is because the males use desynchronized calling, enabling individual recognition.

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Amphibians

Class Amphibia (“to live a double life”): Frogs, salamanders, toads

Amphibians live a “double life” by being able to survive both on land and in water. Unlike reptiles with dry, scaly skin, amphibians have smooth skin that needs to be kept moist. Many live in the water through development and start life with gills, and then transition to breathing with lungs. They can get even more oxygen through cutaneous respiration, or breathing through their skin. This class represents the first animal group to be able to efficiently walk on land—aided by the well-defined limbs that gave them a “leg up” on their finned competitors.

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Male Japanese tree frogs apply a mathematical algorithm to take turns calling, enhancing the chance a female can find a specific mate.

Male Japanese tree frogs use their calls to attract mates, who are able to locate the male frog from the vocal expression. Potential for confusion arises for females locating their male callers when the males are in close proximity to each other; but the tree frogs have adapted to such confusion by desynchronizing their calls. Desynchronizing simply means that these frogs have the capacity to time their vocal expression at altered intervals so the females are able to differentiate the vibrations and then choose which male they will locate. The process of the desynchronization follows a mathematical algorithm that has been calculated by researchers from Polytechnic University of Catalonia.

This algorithm has practical application for color graphing in which colors are associated with certain nodes on the graph. When nodes are connected to each other, there is opportunity for overlap among colors; the new algorithm eliminates this overlap and allows for distinct node-to-node connection. The networking between nodes is similar to wireless connections wanting to avoid frequency overlap.

Last Updated February 2, 2017

References

Journal article

Distributed graph coloring: an approach based on the calling behavior of Japanese tree frogs.

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Reference

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