21.11.2018 – Click, click, click – Enjoy your meal!
Our Ribeira Brava, this beautiful traditional fishing boat sailed today with expectant guests to the sea. The largest toothed whales, the Sperm whales (Physeter macrocephalus) were not long in coming. Only three miles off Calheta’s coast we arrived at our sighting position. Here and there and there were single animals or Sperm whales to be found in groups. Although the group structure of Sperm whales living in matriarchy is very narrow, they are sometimes scattered. One can imagine that it would be difficult for these big whales to get enough food if they dived in close cohesion. It definitely makes more sense if they scatter for this purpose more spacious and after hunting meeting up again.
When Sperm whales submerge, it is important to orient themselves at a certain depth via echo clicks. In the first few minutes, however, there is still no click to hear, possibly the whale can in the previously reached depths still optically oriente himself. The first clicks, which the whale announces, then come every second. The animal will keep this frequency now for another two to four minutes. But suddenly the click rhythm changes, twice a second the strong and clear sound is sent out. The Sperm whale has reached its hunting depth. But wait, what happens now, the clicks are getting faster and faster, followed by a break of seven to fifteen seconds. What exactly happened? The two-second click probably hit on prey, now the effort is intensified, the clicks are faster to really find the luscious bit and then in this little interruption, the delicious meal is devoured. This sequence of two-second clicks, accelerated clicks and pauses are repeated several times. However, as the enriched oxygen does not last forever, the whale now begins again with the process of emergence, recognizable by the now changed click-rhythm, which is now sent out again every second. During the last 300m, the whale shrouds again in silence until it pierces the surface of the sea with a loud “Pschhhh” and breathes powerfully and frequently to let oxygen flow into its lungs.We have witnessed this hopefully successful plunge into the blue restaurant several times today and hope the food has tasted good.
By Fatima Kutzschbach
Sightings of the day
10:00 Sperm whales
15:00 Pilot whales, Bottlenose dolphins