Single
Whales and Mother Whales Use Different Calls At Different Depths
Anaid Ibeth López Urbána (a,b) - soyibeth@gmail.com
Jorge Urbán Ramirez (b) - jurban@uabcs.mx
(a) Programa de Maestría
en Ciencias del Mar y Limnología, UNAM, México,
(b) Laboratorio de Mamíferos
Marinos
de la Universidad Autónoma
de Baja California Sur, UABCS Baja California Sur México,
Aaron M. Thode - athode@ucsd.edu
Melania Guerrac
- melania@mpl.ucsd.edu
Scripps Institution
of Oceanography, San Diego, California
Carmen Bazúa Duránd - bazua@servidor.unam.mx
Universidad Nacional Autónoma de la
Ciudad de México, Facultad de Ciencias, laboratorio de Acústica,
Popular version of paper 5pABa4
Presented Friday afternoon, November 19, 2010
2nd Pan-American/Iberian Meeting on Acoustics, Cancun, Mexico
The gray whale uses sounds to obtain information about
its environment and to communicate with other gray whales. Two different demographic groups of gray
whales visit San Ignacio Lagoon: mothers who give birth to and raise their
calves, and singles, who come here to mate. Since 2005 a group of scientist has
been studying their vocalizations to learn, among other things, if mothers with
calves produce the same calls than the singles whales. A second question we
seek to answer is at what lagoon depths these vocalizations are produced. To investigate
these questions , we deployed sound-recording tags on gray whales in San
Ignacio Lagoon by attaching them onto the animal’s skin with suction
cups. We recorded 5 types of calls, labeled “conga”, “quejido”, “croac”,
“purr” and “ronroneo”.
Results show that mothers mainly use the “conga” and the “quejido” type calls while the single whales produced primarily the “ronroneo”
and the “croac”. However, the “purr”
call was produced about as frequently by mothers and singles whales alike. With
regards to where in the water column these calls are made, it seems that mothers have a preferred depth for calling: 79% of their
vocalizations were made at the surface, compared to single whales calling at
the surface only 21% of the time. Conversely while sitting at the bottom,
singles whales produced 84% of their calls while mothers only use this depth to
produce 16% of their vocalizations.