21.08.2024 – Stars n’ Stripes

If you’ve been on one of my tours and heard my opinion on the use of phrases like “ocean super highway” rather than Gulf Stream or referring to a sea turtle’s pelagic phase as its “lost years,” you’ll know this blog is unlikely to be about the United States. Today’s blog was inspired by a young guest who today asked me about the true difference between Atlantic spotted (Stenella frontalis) and Striped (Stenella coeruleoalba) dolphins. As all us annoying semi-teacher types do, I flipped the question, “What do you think the difference is?” After some thinking, I got my answer short and succinct: “One has stars [spots] and one has stripes.” Is that all there is to it? As the acute-eyed and perhaps scientifically versed amongst you will have noticed, they belong to the same genus, “Stenella.”. This genus consists of 4 dolphins, with spinner dolphins (Stenella longirostris) being the only ones we do not see in Madeiran waters (although Pantropical Spotted Dolphins (Stenella attenuata) are yet to be confirmed).*

So what is this difference between spotted and striped… Well, thinking about it, ultimately they are both midsized, showy, excitable pelagic dolphins who change their colouration when they age. Um, wait, no. They both live across wide ranges and prefer warmer water. Not really a difference, is it? Ive got it! Both live till about their 60s! Both live in groups of up to 50 animals! Both are highly social and feed on small schooling fish and squid!  If we were looking for a true difference, all genetic and scientific pedantic differences aside, at the very heart of it, I guess one has stars and one has stripes…

*Side note on this topic: there is also one further member of the stenella genus, the Clymene dolphin (Stenella clymene), which is a hybrid between striped/spinner dolphins. The Wikipedia (it’s not always bad !!) article for this species describes its colouration as “classic cetacean Neapolitan,” meaning the standard dark grey, light grey, and white colour scheme that we see on many whales and dolphins. Sadly, I couldn’t access the article that Wikipedia attributes this phrase to, but I love it and will be stealing it.

by Peter Worth

Sightings of the Day

Ribeira Brava

09:30 Striped Dolphins

13:30 Striped Dolphins

Stenella

09:30 Striped Dolphins, Rough-toothed dolphins

14:00 Striped Dolphins, Rough-toothed dolphins

17:00 Atlantic spotted dolphins, Rough-toothed dolphins