Since 2013 our group (with support from the non-profit Ocean Foundation) has been collaborating with the Universidad Autonoma Baja California Sur (UABCS) to study the acoustic environment off Cabo San Lucas during the winter humpback whale breeding season. Punta Gorda and Cerros Colorados are locations with relatively little vessel traffic; Punta Ballena is near the mouth of Cabo San Lucas harbor.
A preliminary analysis of the 2013 deployments from Punta Gorda indicates that there is a 24 hour cycle in the background noise levels between 50 and 500 Hz, which is dominated by humpback song:
Near the harbor, however, humpback song no longer dominates the band, and the 24 hour cycle vanishes:
In 2013 our colleagues at UABCS began tagging animals with the Acousonde bioacoustic tag. A summary of taggings to date:
Here is a picture of what the tag looks like on a mother/calf pair on Feb. 21:
Here are some samples of sounds recorded on the tags.
The escort of a mother/calf/escort group was tagged on March 13th. At 13:06, two whups follow a short exhalation.:
Three social calls from February 14th are shown here from a recording on a tag attached to a mother whale alone with her calf. It is likely that this call did not come from the mother, but rather from the calf alongside her as visual observations would indicate that no other whales were at the surface within a mile. The mother and calf stayed very close to the shore near Punta Palmilla for the first few hours of this recording:
Song can be captured on the acoustic tags from animals up to a few miles away. Two small competitive groups were on the surface at least a mile away from this tagged mother whale and her calf on February 14th at 11:52 when a song snippet was recorded:
On Feb 10 at 13:49, the escort of a 14-whale competitive group had been tagged. While the tag data overall would indicate that the group was rather acoustically inactive, the few recorded calls showed up clearly on the tag. This sample may be from an animal nearby the escort and not the escort itself.