Today my expectations were exceeded. I have a vast list of animals I could mention which were simply splendid. To just mention a few; penguins fishing, pelicans nesting, sea lions playing, boobies diving, marine iguanas nesting, and cormorants drying their wings. Of course all of this in only one visit. But definitely, the dolphins blew my mind away.
Early this morning we had bottlenose dolphins (Tursiops truncatus) bow riding at least 20 times as we circumnavigated Roca Redonda. These fascinating creatures evoked smiles and laughter all around us. As if this was not enough, at least five hundred (this being an estimated number) common dolphins (Delphinus delphis) made us leave our breakfasts and run to the bow of the ship to admire them. Five hundred of them! This was surely my best sighting ever of these dolphins - I have seen them before but not in such an enormous numbers.
To determine the number of a cetacean group is not easy. There are of course the obvious physical restraints. It is difficult to estimate the size of a group when most of its members are under the water and may not surface as often as some of them do, and sometimes they may be too far to see. Dolphins may congregate to fish, but how many are really fishing? It is impossible to know. Because of these and other variables, both between species, and within the species itself, it is more than difficult to establish group size.
Living in groups as dolphins and other animals do, provides several advantages. For instance, it may be helpful to have friends for protection against predators, foraging may be easier in a group than singly and the group may provide a meeting place for males and productive females. Whatever the reason this group had today to swim in a large number we'll never know but surely we had a thrilling time watching them.
