09.12.2019 – Smooth transition
Today our traditional boat ventured out onto the Atlantic twice in search of cetaceans. Both times, the calm ocean surprised us with beautiful sightings of Short-finned pilot whales (Globicephala macrorhynchus) and in the morning we additionally had the pleasure of seeing a compact group of Short-beaked common dolphins (Delphinus delphis), while in the afternoon the Atlantic was decorated with the gleeful company of our summer dolphins, the Atlantic spotted dolphins (Stenella frontalis).
While the pilot whale communities are present all year round making them one of the best documented species visiting the archipelagos waters, the same cannot be said about seasonal visitors such as the common and the spotted dolphins. Their patterns of habitats are strongly linked to water temperature, with the spotted preferring the warmer waters during the summer months ands the commons being more frequent in winter.
The fact that both species are quite abundant at this time of the year may be an indication of an extension of the transition seasons providing adequate conditions for both species. Another possibility could be an extensive availability of prey but I suppose the answer is written in the stars as long as these populations are not properly documented. Photographing and identifying each dolphin belonging to these large groups that only temporarily use these waters, presents quite a challenge to scientists studying the population dynamics of these interactive dolphins but perhaps we can find more efficient means of conducting such research in future.
Until then we will simply enjoy these two curious and special species of dolphin as they share the deep blue waters outside the Madeiran archipelago.
By Paula Thake
Sightings of the day
10:00 Short-beaked common dolphins, Short-finned pilot whales
14:30 Atlantic spotted dolphins, Short-finned pilot whales