Image from the Biodiversity Heritage Library.
Contributed by Museum of Vertebrate Zoology, University of California, Berkeley.
| www.biodiversitylibrary.org
Transcription
1974
11 Dec Berkeley
0230-0330 Counted hootings of a pair of
horned owls who were duetting.
(1) Male initiated duets in 40 min. 45
(2) Female " " " "
but I immediately following noticed 7
of overlapping.
(3) Female initiated duets 13
(4) Female initiated duets, but immediately
following 3
(5) Female only hooting 6
(6) Female only hooting. 3
Hooting had commenced about 10 minutes
before I began counting. Male stopped
about 5 minutes after I stopped counting.
Male called a sequence of three hoots.
Female answered, usually with
short notes preceding their hoots. If
I overlapped randomly, but usually
coming on the male's second note, occasionally
begun a pair-bonding a period after he did,
or was delayed.