The weather kept us ashore for almost a week, but today we set off again. Not far from the coast, Drumond, our spotter, had found a large school of Bottlenose dolphins (Tursiops truncatus) with some calves. We were able to accompany them for a while before heading out. Drumond had discovered Sperm whales (Physeter macrocephalus) for us. There were 5-6 animals in total, including a calf travelling with two adults. Both species, as different as they are, were each in their own way a wonderful, special experience.
The reproduction of sperm whales is a complex process that is strongly characterised by social structures and the migration of the animals. Although Sperm whales are long-lived, they only have one reproduction rate. Female Sperm whales reach sexual maturity at around 7 to 13 years of age, while males are often only able to reproduce at 18 to 21 years of age or even later. Some of these large, male toothed whales often only begin to reproduce successfully at around 30 years of age, as they become more dominant with increasing age and size and are able to assert themselves in fights for mating partners. The gestation period for Sperm whales lasts around 16 months. After this phase, the female gives birth to a single calf. Female Sperm whales usually only have a calf every 4 to 6 years. This long period between births is due to both the long suckling period and the intensive parental care. Sperm whales invest a lot of energy in rearing their calves, which contributes to the low reproduction rate. This means that a female may only give birth to around 4 to 7 calves in her lifetime.
From midday onwards, the weather set the tone again. Our spotter was confronted with a wall of rain that obscured his view. Unfortunately, all other tours had to be cancelled. It certainly wouldn’t have been fun for our guests to drive across the sea in the pouring rain.
By Fatima Kutzschbach
Sightings of the day
Ribeira Brava
14:30 Cancelation due to weather condition
Stenella
09:30 Bottlenose dolphins, Sperm whales
13:30 Cancelation due to weather condition