Eistla’s time-depth dive record overlaid with occurrences of type E and C signals.

• 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.g002

The top panel shows Eistla’s entire Acousonde record. Yellow dots represent type E calls, while black dots represent type C. In subpanels A-G, the x-axis is labeled with the start time and date of each panel, and each vertical interval represents two minutes. Panel A: Type E calls produced immediately following Eistla’s release. Panels B-C: A call and response exchange between type E and C. Panel D: Eistla returns from a ~230 m dive and five type E series (16 calls in the series) are produced while she lingers near the surface followed by one type C series (4 calls in the series). Panel E: One type E call followed by a type C response with type E signals continuing as Eistla leaves on a ~400 m dive. Panel F: Five type C series (14 calls in the series). Panel G: One type C response to a possible other whale (not featured in figure) followed by a type C series, two type C calls with a pulsed sound response (not featured in figured), a call and response exchange between type E and type C, and two type C series. Note that some signals are overlapped and therefore not all signals are clearly visible in the figure.