Four new species of horseshoe bats that have different echolocation frequencies have been discovered in Africa.

Researchers led by Professor Peter Taylor of the University of Venda, South Africa, identified the four new species, which was first thought to belong to one species, the Hildebrandt's Horseshoe Bat, known as the Rhinolophus hildebrandtii that was discovered in 1878.

When they analyzed bats' echolocation, which they use to navigate when searching for prey in total darkness, they found that the frequencies of the calls made by the bats differed from each other.

Horseshoe bats got their name because of their noseleaves which has a horseshoe-shaped fold that the bats use to make echolocation calls. While other bat species use their mouths to send sonar calls, the horseshoe bats use their nose to send the calls which helps them to focus on the sound.

Experts revealed that the bats are cryptic species that belonged to the species of R. hildebrandtii with some significant differences in their echolocation calls and DNA. Cryptic species are those that cannot be differentiated by their looks and morphology but needs a DNA analysis to study differentiate the species from others, reported LiveScience.

The four new species include the Mount Mabu horseshoe bat (Rhinolophus mabuensis) from the mountainous region of northern Mozambique, Cohen's horseshoe bat (Rhinolophus cohenae) that is found in South Africa's Mpumalanga Province, Smithers' horseshoe bat (Rhinolophus smithersi), and the Mozambican horseshoe bat (Rhinolophus mossambicus).

"These bats are textbook examples of cryptic species, meaning that they are really very difficult to tell apart just based on their looks and morphology," said study author Samantha Stoffberg of Stellenbosch University, according to Times Live.

"DNA comparisons have made it possible for us to clearly distinguish between these species," she said.

The findings of the study are published in the journal PLOS ONE.