Expedition report 23th of August 2023
Conditions of the Day
Today we have had winds between …
Reported Sightings
During the expedition we observed two Sperm whales and numerous Cory’s shearwaters
Cetacean Sightings
Sperm whales
The Sperm whale is grey to brown with a small and triangular dorsal fin. The head is rectangular and the blowhole is situated on the front left side. It is the biggest of the toothed cetaceans with males being bigger than females and reaching up to 18 m and weights of 50 tons, while females only reach 8 to 12 meters and weigh between 20 and 24 tons. Their lifespan is more than 70 years with males becoming sexually mature between 10 and 20 years old and females around 9. The gestation period is about 14-16 months. They nurse their calves for long time, females will remain in the mother’s social group while male’s will leave the mother’s group when they are between 7 and 14 years old going in groups of young males and when older they can be in small groups or alone. The sperm whale is a deep diver feeding mainly on squid and octopy.
Here in the Azores they are usually found in waters with more than 600 meters depths and although they can be seen all year round, they are more abundant over the warmer part of the year. We mostly encounter female groups with some juveniles and calves, gathering in groups between 6 and 15 animals. Occasionally we also observe large adult males or groups of young males.
On todays expedition we encountered two young male sperm whales that belong to a 10 individual’s bachelor sperm whale group.
The first one spotted was an animal called “The Duke of Westminster”. We sighted Duke for the first time in August 2022, while he was around the south area of São Miguel for over 20 days. This year he has showed up again in August, in the same area where he was one year ago.
During the sighting we could observe the animal logging, resting on the surface, and after couple of minutes going for a feeding dive, lifting the fluke.
The second sperm whale spotted was an animal spotted just once last year. We found him few moments before going for a feeding dive, we could see how he was curving and lifting the fluke.
Cetacean sighting spots
Other species sighted
Cory's shearwater
The Cory’s Shearwater is seabird with a yellow beak, warm pale brown upperparts and white belly. They come every year in spring to reproduce. The Azores host more than 75% of the Cory’s Shearwater entire population. Staying in their nesting ground all spring and summer until their chicks are grown enough to try their first flights.
In our daily expeditions we often see them both flying close to the surface or seated in the water. Sometime they associate with dolphins and whales in feeding spots as they are feeding on the same kind of fish.
SeaColors Research
Every day in our expeditions we are collecting data about the wildlife that we are observing in order to increase the knowledge and work for their conservation.
During our expeditions we record the position, specie, number of animals and behavior of the species sighted. For big dolphins, sperm whales, beaked whales and baleen whales we also get pictures for photo-ID. Depending on the specie we focus more on the dorsal fin, the head or the fluke of the animal.
There are different ways to study animals behavior. In our case to study cetacean and other species behavior in the water we use the GoPro. Then we are able to capture images of different behaviors and interactions such as feeding, reproduction, bowriding, socializing, etc.
In this video we are showing a group of spotted dolphins feeding on a big beat ball with Cory’s shearwaters and Tuna’s.
In this other video we can observe a loggerhead turtle approaching the boat with some pilot fish underneath.
The Sperm Whale Project
The Sperm Whale Project was born out of the desire to answer the questions that arose when we were at sea with the sperm whales and the desire to understand and know more about their behaviour, social structure, communication and feeding habits.
For being able to answer those questions, every time we go out to sea we try to gather as much information as possible about the group of sperm whales we have in the area. We take photographs to identify them, if the circumstances are right we film them either with the GoPro from the boat or with the drone to get their behavior, identification, morphometrics and body health. While following them we also write down their movements and the directions in which they are diving.
For the acoustic detection and area distribution we use our directional hydrophone. When sperm whales are diving they use echolocation to know what they have around and to find the prey. Those clicks can be heard for the other animals and also for us and so we can know where they are respect to the boat.
We might also collect skin or poo samples. Sometimes when the whales dive they leave some poo or skin on the surface which we can collect in a non-invasive way and that can be very useful to get the genetics of the sperm whales and also from the preys so we get more knowladge about what they are feeding on. Sometimes we also find pieces of squid and octopus that they bring to the surface to the depth so we can know in which species they are feeding on.
