First acoustic evidence of signature whistle production by spinner dolphins (Stenella longirostris).

A dolphin's signature whistle (SW) is a distinctive acoustic signal, issued in a bout pattern of unique frequency modulation contours; it allows individuals belonging to a given group to recognize each other and, consequently, to maintain contact and cohesion. The current study is the first scientific evidence that spinner dolphins (Stenella longirostris) produce SWs. Acoustic data were recorded at a shallow rest bay called "Biboca", in Fernando de Noronha Archipelago, Brazil.

Acoustic recording of false killer whale (Pseudorca crassidens) from Mexico (L).

This study collected acoustic information on false killer whales (Pseudorca crassidens) in Mexican waters, close to Roca Partida Island, Revillagigedo Archipelago. In total, 321 whistles were collected after we found a group with at least ten individuals. The high prevalence of ascending contour types [upsweep (type I): 42.