Earth & Conservation

Frog Sings Like a Bird, Bobs Head for Mates

A Brazilian frog will do almost anything to grab the attention of females, including singing, toe tapping, arm waving and squealing.

Brazilian torrent frogs clearly do not want to be ignored, as new research finds they sing, squeal, wave their arms, tap their toes and more when around other frogs, and particularly members of the opposite sex.

The frogs (Hylodes japi) could have the most complex communication system of any amphibian, suggests the paper, published in the journal PLOS ONE.

Fábio Perin de Sá of Sao Paulo State University and colleagues wrote that the communication of the frogs "is undoubtedly more sophisticated than we expected and that visual communication in anurans (tailless amphibians) is more widespread than previously thought." They added that "this is especially true in tropical regions," likely because of the higher number of frog species there and ecological factors, such as diverse microhabitats.

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The following three videos, which run in sequence, illustrate only some of the frog's skills, such as singing like a bird and doing leg displays.

De Sá and his team made the recordings in the biological reserve of Serra do Japi in the state of Sao Paulo, southeastern Brazil. The forested region provides important habitat for many species of plants and animals.

The researchers documented the calls as well as the visual displays of the frogs. The latter consisted of toe trembling, toe flagging (which reveals the frog's silver-white underside), foot shaking, hand shaking, arm waving, head bobbing, full body jerks, and much more.

Video: 3 Weird Frog Discoveries

A particularly complex move is the "head snake." Males seem to use this to mesmerize females. While approaching prospective mates, the males will move their heads from side to side as snakes do when in front of a snake charmer. The males do this looking right into the eyes of the desired female and at very close range, but not touching her.

Actual courtship is quite a scene. While peeping and squealing, the males tremble their toes, engage in toe flagging, foot shaking, hand shaking, arm lifting, head bobbing, body jerking and perform throat displays. While all of this is going on, the females remain motionless. Only later, with a subtle lift of an arm as if to say, "Yoo hoo, I'm ready," does a female often signal her willingness to mate. She then rubs part of her body on the male's back, with her hands gently touching him. Intercourse usually starts thereafter.

The scientists also observed that females could stimulate males to emit courtship calls with just a lift of their arm, most often the left one. Such control has never been documented before in frogs.

Brazilian Frogs Use Their Venomous Heads as Weapons

Another novelty: the researchers found that males could choose which of their two vocal sacs could be blown up, like a balloon, and used for visual displays. Each sac, arm and limb seems to be tied to unique meanings, giving the communication system tremendous flexibility and depth.

Brazilian torrent frogs have a wide repertoire.

After nearly 5 years of exploration in mountainous areas of the southern Brazilian Atlantic Rainforest, a team of researchers has uncovered seven new species of very tiny, brightly colored frogs from the genus known as Brachycephalus. None are bigger than an adult thumbnail.

The tiny amphibians live in mountain top regions in the southern Brazilian Atlantic Rainforest that are extremely isolated. Since their habitat is so limited they are extremely vulnerable to extinction. Shown is the species

Brachycephalus auroguttatus

.

Frogs in this genus have been known since the 1800s, but these seven species hadn't previously been identified. These tiny frogs generally have three toes and two fingers, instead of the five toes and four fingers found in most frogs. All of the frogs are less than 0.4 inches in length. They vary mostly in their skin color and texture. Shown is the rough-skinned species

Brachycephalus verrucosus

.

Brachycephalus olivaceus

is the color of a greenish-brown olive. The first species of Brachycephalus was described in 1842 by the German naturalist Johann Baptist von Spix. But most species in the genus have been discovered only in the past decade. That's due to their extremely remote habitats, which are difficult to reach. "Although getting to many of the field sites is exhausting, there was always the feeling of anticipation and curiosity about what new species could look like," said Marcio Pie, a professor at the Universidade Federal do Paraná, who led the project.

Brachycephalus boticario

(shown) features bright orange skin with dark, bumpy sides.

The frogs were all found living among leaves on the forest floor. Their home -- cloud forests -- are highly sensitive to climatic changes.

Brachycephalus leopardus

features flashy yellow skin dotted with dark spots (like a leopard).

The tiny frog

Brachycephalus fuscolineatus

has yellow skin with a greenish-brown stripe running down its back. The researchers believe there may be even more species of the frogs in the remote regions. "This is only the beginning, especially given the fact that we have already found additional species that we are in the process of formally describing," said Luiz Ribeiro, a research associate to the Mater Natura Institute for Environmental Studies, in a press release.

The study

, titled "Seven new microendemic species of Brachycephalus (Anura: Brachycephalidae) from southern Brazil," was published today in PeerJ, a peer-reviewed open access journal.