Short phrases consisting of simple hoots, various more complex hoots, and specific quaver notes produced by tremulous opening and semi-closing of the mouth during long hoots. Short phrases produced by males and females, but quaver notes are typically produced by males only. Female great call very similar to that of H. agilis, but usually longer, with longer notes, and with more pronounced first climax, and fewer notes dedicated to second climax than in H. agilis. Male produces coda. Male solo song bouts and duet song bouts.
a. male short phrases (Rheine Zoo, Germany, 5 July 1987; and Twycross Zoo, United Kingdom, 3 Oct. 1988)
b. great call sequnce consisting of female great call with male contribution (Paignton Zoo, United Kingdom, 20 Oct. 1988)
|Solo song, adult mated male "Carlo", Rheine Zoo, Germany, 5 July 1987.|
|Solo song, adult mated male "Harvey", Twycross Zoo, U.K., 3 Oct. 1988.|
|Duet song, adult pair "Pupuce" and "Anvers", Mulhouse Zoo, France, 15 Sept. 1988.|
|Duet song, adult pair "182/1" and "Sally",
Paignton Zoo, U.K., 21 Oct. 1988.
The two infant offspring of this pair do not contribute to the song bout.
|Isolated solo great call of widdowed adult female,
Zoo Al Maglio, Switzerland, 23 Nov. 1987.
The adult daughter of this female is also kept in the same cage, but does not contribute to the great calls of her mother. It's raining during this tape-recording.