Source: INBio Costa Rica

People who live in the rural areas of intermediate elevation in Costa Rica, which happens to be a major portion of the country, are used to hearing a diversity of wild noises in the predawn hours, or after the sun goes down. While many of these animal calls come from the farms and forest areas surrounding residential neighborhoods, some homeowners and tenants are often awakened by noises that seem to originate from their own homes.

There are two common nocturnal and early morning noises in Costa Rica that the uninitiated tend to confuse with bird calls, when in fact they come from a small field rodent and an even smaller reptile that is very comfortable moving into people’s homes and waking them up in the night with loud chirping and clicking calls. In a country full of interesting animals, a singing mouse and a loud clicking lizard should not surprise the people of Costa Rica, but the ongoing scientific research that is conducted on Scotinomys teguina (singing mouse) and Hemidactylus frenatus (house gecko) is worth considering.

Singing Mice and Human Speech Disorders

The Alston Brown Mouse, known in Costa Rica as the short-tail singing mouse, is a small rodent species that measures between 66 to 86 millimeters from the tip of its nose to the tip of its tail. It is only larger than the pigmy rice rats that are abundant in coffee farms, and it is almost completely brown -it lacks the white bellies often seen in other small field rodents. This tiny mammal can be found in the forests located halfway to the craters of our volcanoes, it feeds on insects, it is mostly diurnal but most active at dawn, and it has a song that was recently described by Science Daily as:

“[…] a rapid-fire string of high-pitched chirps called trills used mostly used by males in dominance displays and to attract mates. Up to 20 chirps are squeaked out per second, sounding similar to birdsong to untrained ears. But unlike birds, the mice generally stick to a song made up of only a single note.”

To the untrained ear, these mice sound just like birds. Scientists have determined that singing mice use these songs to communicate over long distances. Steven Phelps, a researcher from the University of Austin is investigating these rodents and, according to Science Daily,

“[gather] information that could help scientists understand and identify genes that affect language in humans.

To find parts of the gene that may contribute to the singing mouse’s songs, Phelps is searching for sequences unique to the singing mouse and testing them for evidence of natural selection, which weeds out mutations with no likely observable effect from those that are likely to contribute to singing behavior.”

Geckos and Futuristic Surgical Bandages

If you see these adorable and loud lizards in your home in Costa Rica, consider yourself lucky. Geckos are not only considered to be harbingers of good fortune in Asian cultures, they also happen to be efficient exterminators. Geckos arrived in Costa Rica from Asian ports where they became stowaways on trading ships. They will enter homes chasing after insects attracted by light bulbs, or they may be seeking warmth. Once inside, they will become active at night and emit up to three different loud clicking calls, similar to what birds flying in formation sound like.

These tiny reptiles can be found in the Central Valley and all over the Pacific coast of Costa Rica. Geckos are amazing climbers; they are able to stick to just about any surface thanks to tiny hairs on their curious toes. According to a recent article in Science Daily, researchers from the University of Akron are looking into the powerful grip of geckos to develop a bandage:

“[…] geckos don’t fall from trees during downpours in the tropics. What, then, makes them stick? The team hopes to make that discovery in order to create synthetic materials that hold their grip in wet environments, such as inside the body, for surgical procedures.”

The next time you are awaken by gecko clicks or singing mouse calls in Costa Rica, think about how these tiny species may be holding clues to make our lives better.