21.08.2022 – With(out) – The little difference

There was still a gray cloud cover over this Sunday morning. At the beginning of the tour, we were able to observe a tropical whale (Balaenoptera edeni), which glided through the morning just as relaxed as we did. A lot, a lot of time between this and the second sighting went by. The gray was above us, below us, the horizon, the separation of sky and sea barely perceptible. It made you feel like you were chugging through timelessness. Daily thoughts could just slip away into nothingness. That too can be very relaxing. Bottlenose dolphins (Tursiops truncatus) concluded our morning tour. After staying in the timeless space, our guests enjoyed the active power of the dolphins.

Incidentally, there is a crucial difference between these two observed species. Bottlenose dolphins, like all dolphins, are a subgroup of toothed whales. Toothed whales use their sonar to find their way. In the head area of dolphins, there is a so-called melon, through which the sound is emitted. This sound falls on an object and comes back like an echo, is picked up by the “acoustic window” (oil cushion) on the right or left and is conducted via this oil channel to the inner ear, from where the information is sent to the brain.

Baleen whales do not have sonar to track their food. Ultimately, it’s not fully understood how they track their food, but there are a few theories. It is assumed that they can acoustically perceive the movements of the schooling fish very well. If a school of fish changes its direction, a sound is produced which the respective baleen whale may perceive precisely. An acoustic sound travels faster and further underwater than in the air. So this could be an explainable approach. The second theory is also very interesting. Bowhead whales, for example, have been found to appear to be able to smell above water. Studies that have not yet been completed are trying to find out whether this also applies to other baleen whales. Who does not know this pleasant, fresh sea scent. I associate this fragrant breeze with the feeling of freedom and purity. A wonderful scent! When the zooplankton ingest phytoplankton, Dimethyl sulfide (DMS) is formed. It is assumed that baleen whales orientate themselves on the concentration of the DMS. I find this a fascinating theory.

By Fatima Kutzschbach

Sightings of the day

Ribeira Brava

10:00 Tropical whale, Bottlenose dolphins

15:00 Bottlenose dolphins

Stenella

10:00 Bottlenose dolphins, Striped dolphins, Atlantic spotted dolphins

15:30 Bottlenose dolphins

17:30 Bottlenose dolphins, Atlantic spotted dolphins, Tropical whale