Acoustic clue: bringing echolocation call data into the distribution dilemma of Pteronotus (Chiroptera: Mormoopidae) complexes in Central America

Abstract

In Central America, the distributional limits and the contact zones of some Pteronotus species, such as the naked-backed bats and the lesser mustached bats, are unclear. To elucidate the distributional dilemma of the species groups Pteronotus fulvus + Pteronotus davyi and Pteronotus psilotis + Pteronotus personatus in Central America, we studied the acoustic variation of their echolocation calls along the range of possible contact zones and the existence of distinct phonic groups. We performed hierarchical k-means clustering on principal components (HCPC) using acoustic samples from Mexico, Honduras, El Salvador, Nicaragua and Costa Rica to describe the global acoustic diversity, possibly overlooking differences between species groups. We assessed whether those acoustic differences were related to the geographical distance and geographical location. We found evidence of sympatry for three phonic groups within each species complex, without a clear correspondence to the known distribution of species. The changes in frequency of their echolocation calls seem to follow a similar pattern to the geographical variation in body size of the species. Future studies in Central America should include an integrative sampling of individually captured, tagged and recorded bats to help in resolution of the distribution dilemma raised here.