Type C examples from samples used for parameter extraction (n = 7).

• Main Authors: Audra E. Ames (11349386), Susanna B. Blackwell (10013873), Outi M. Tervo (10013864), Mads Peter Heide-Jørgensen (7869812)
• Format: Still Image
• Language: unknown
• Published: 2021
• Subjects: Neuroscience; Evolutionary Biology; Ecology; Sociology; Infectious Diseases; Biological Sciences not elsewhere classified; Physical Sciences not elsewhere classified; stereotyped call type; monodon monoceros </; gregarious toothed whales; e .; biphonations; div >< p; provide additional support; contact call use; stereotyped mixed calls; hypothesize also contribute; narwhal mother produced; contact calls; provide evidence; narwhal mother; narwhal (<; calf contact; vocal signatures; strictly reside; sounds available; signal types; second prominent; remained close; mother ’; mostly descriptive; maintaining mother; life history; known regarding; individually distinctive; high arctic; determine whether; broad range; believe belonged; became apparent; Arctic; Monodon monoceros; narwhal*; toothed whales
• Online Access: https://doi.org/10.1371/journal.pone.0254393.g003

In all panels, note the upper frequency harmonics, indicative of a signaler facing the Acousonde. In the far right panel, note the end of a type E call (indicated by red asterisk) prior to the beginning of a type C response. Yellow boxes indicate type C overlapping tonal components. Spectrogram parameters: DFT size 512, 256 sample hop size, and Hann window 512 samples.