World Whale Day: Taking a look at the baleen whales of the Azores

Today we want to celebrate the World Whale Day with you. Since 1980, every third Saturday of February the Whale Day is commemorated worldwide. What a perfect moment to share our knowledge and raise awareness about these incredible giants! On this post, we will let you know more about the baleen whales sighted in the Azores and how little we know about them!

In the Azores there have been reported 28 different species of whales and dolphins so far (Silva et al., 2014). However, some of them were just sighted occasionally, while others are frequently observed around our waters. Seven out of these 28 species belong to the Misticety group, i.e. baleen whales: blue whale, fin whale, sei whale, humpback whale, Bryde’s whale, minke whale and North Atlantic right whale. As a brief reminder, baleen whales have baleen plates instead of teeth and two blowholes on the top of the head.

Every year in spring we are luckily to sight on some of our tours the two biggest animals that have ever existed on the face of the earth: the blue whale and the fin whale. According to our data, these two species are mostly sighted between March and June every year. To have an idea, from all our sightings of blue whales, only two have been recorded out of this period (González et al., 2013; González et al., 2014; González et al., 2018).

Fin whales however, even sighted also mostly in spring, have been observed as well the rest of the year, especially since 2014 (Ojeda et al., 2018). Sei whales are sighted as well every season (Ojeda et al., 2018), but they use to arrive a bit later than blue and fin whales. When we sight these giants, we always wonder where are they coming from and where are they going to. And we must say that there is not an easy answer! Only a couple of studies have tracked by satellite these species in our region. They tagged some whales in spring in the Azores, and followed their routes towards northern waters (Silva et al., 2013). They discovered that blue and fin whales were travelling directly northwards after feeding for some days in the Azores, and they didn’t stop on their journey (Fig.1). However, sei whales were travelling northwest, so following a different route in spite of being sighted on the same area at the same time (Fig.2) (Prieto et al., 2014). Our photo-identification results show that some of the whales come back and again to the islands, so they really enjoy the Azores!

Humpback whales are sighted mainly in spring too (van der Linde et al., 2013; González et al., 2014), but particularly the last few years, sightings in winter were not uncommon. With photo-id, we confirmed the northward migration with a whale sighted in Cape Verde and in São Miguel with only 27 days in between! However, a study that tagged some humpbacks in the Northern North Atlantic (whaletracking2018.uit.no), show how they are travelling SE (heading the Caribbean) during winter and spring time as well (Fig.3).

Bryde’s whales are not frequently sighted around São Miguel. In the last 11 years, they have been sighted only in 2009, 2013 and 2017 (van der Linde et al., 2013). They are usually found in warmer waters, so their occurrence in our waters may be linked with some SST anomalies. A study made by Steiner et al., (2008) explained that favourable conditions could be temporal extended up to our latitudes, allowing the presence of this tropical species in the Azores.

And to finish our list of baleen whales registered in the Azores, the North Atlantic right whale. It has been reported in January 2009 off the central group (Silva et al., 2012). Luckily, this whale was photo-identified, and successfully recognized in the Bay of Fundy (Canada) before and after being in the Azores.

And this year, the team of Futurismo is ready to continue learning more about the magnificent whales passing by the Azores. Are you ready to join us and help us to learn more about them?

Bibliography

González L, Sardà C, van der Linde, M (2013) Blue whales passing around Azores. Proceedings of the Annual Conference of the European Cetacean Society, Setúbal, Portugal, 8-10 April 2013.

González García L, Pierce GJ, Autret E, Torres-Palenzuela JM (2018) Multi-scale habitat preference analyses for Azorean blue whales. PLoS ONE 13(9): e0201786. https://doi.org/10.1371/journal.pone.0201786

Ojeda V, Montoya C, van der Linde M, González L (2018) Complex temporal distribution of fin whales and sei whales in the Azores. 32nd European Cetacean Society. La Spezia, Italy. DOI: 10.13140/RG.2.2.26471.55204. Poster presentation.

Prieto R, Silva MA, Waring GT, Gonçalves JMA (2014) Sei whale movements and behaviour in the North Atlantic inferred from satellite telemetry. Endangered Species Research. 26(2): 103–113. ISSN: 16134796. DOI: 10.3354/esr00630.

Silva MA, Steiner L, Cascão I, Cruz MJ, Prieto R, Cole T, Hamilton PK, Baumgartner MF. (2012) Winter sighting of a known western North Atlantic right whale in the Azores. Journal of Cetacean Research and Management, 12, 65-69.