Within recent days, the world has learnt of the passing of American writer, author, artist and natural historian Richard Ellis (1938-2024), best known for his many works on marine animals and their environment...
Pouches, pockets and sacs in the heads, necks and chests of baleen whales
Kogia, Shark-Mouthed Horror
Once more I must resort to plundering stuff from the archives, this time an article from TetZoo ver 2, originally published in July 2008 (and available here at wayback machine). Today: the kogiid sperm whales!
Santa Cruz’s Duck-Billed Elephant Monster, Definitively Identified
Extreme Cetaceans, Part 3
Hello faithful and noble readers. Recall the unfinished series on EXTREME CETACEANS? Today we continue with the next episode in said series.
Caption: Stenella longirostris, Phocoena dioptrica and Sousa chinensis, three of the cetacean species covered in the previous parts of this series. Image: Darren Naish.
If you don’t know what the deal is here, it’s that I’m writing about those cetaceans which I consider ‘extreme’, this meaning that they’re “weird, possessing anatomical specialisations and peculiarities that are counter-intuitive and little discussed, and most likely related to an unusual ecology, physiological regime, feeding strategy or social or sexual life”, to quote the first article in the series. And thus we get on with it…
Right whale dolphins. Many dolphin species are aesthetically pleasing because they’re of a beautifully streamlined, attenuate shape, and because they have clean, tidy colour schemes where contrasting blocks of colour are neatly separated, and sometimes augmented or marked by parallel, sweeping lines. This combination – an attenuate, streamlined form and a tidy, well-demarcated colour scheme – is carried to an extreme in the two Lissodelphis species, or right whale dolphins.
Caption: Alcide Dessalines d'Orbigny’s 1847 illustration of the Southern right whale dolphin Lissodelphis peronii. The species is named for naturalist François Peron, the first European to report a sighting of this species. Image: public domain (original here).
Right whale dolphins are mid-sized as dolphins go (about 2-3 m long), short-beaked, and incredibly attenuate. Their pectoral flippers and tail flukes are small, a dorsal fin is absent, and the tailstock tapers to a ridiculous degree. They also have the flashiest, tidiest colour scheme of black and white. They look nothing like the enormous, super-bulky right whales, but do resemble them in lacking a dorsal fin. They’re also incredibly fast, among the fastest of all cetaceans,
Caption: a Southern right whale dolphin group, photographed in 2008. These dolphins are often seen in large groups of 100 individuals or more. Image: Lieutenant Elizabeth Crapo, NOAA Corp, public domain (original here).
Right whale dolphins, incidentally, are close kin of lags (the Lagenorhynchus and Sagmatias dolphins) and probably of the small, short-beaked Cephalorhynchus dolphins (the most familiar of which is the piebald Commerson’s dolphin C. commersoni) (McGowen et al. 2009). But in my headcanon they’re either miniaturised, late-surviving basilosaurids, or whale-mimicking, fully aquatic penguins that have time-travelled from the Dixonian Era to the present. Look at the pictures here and you’ll see what I mean.
Caption: old depictions of basilosaurs and other archaeocetes – those at top are from McEwan (1978) and Naish (1996) – reveal that right whale dolphins are actually descendants of a lineage outside of Neoceti. Or perhaps they’re future penguins, like the Vortex (from Dixon 1981). Images: McEwan (1978) and Naish (1996), Dixon (1981).
The Pesut. In 1989, I thought I knew all the extant cetacean species known to science at the time. So I was blown away when the Today newspaper, which I used to read, ran a two-page feature on a very odd cetacean which was touted as “the only new breed to be discovered in thirty-four years”, this being a reference to the number of years that had elapsed since the scientific naming of Fraser’s dolphin Lagenodelphis hosei in 1956. Evidently, the article was reporting a proposal – seemingly originating with Francois-Xavier Pelletier – in which the cetacean concerned was being considered a potential new species. Grey, toothless and prone to squirting jets of water for fun, it was said to be a freshwater inhabitant of Borneo’s Mahakam River, and was dubbed the Pesut. The what?
Caption: a Today newspaper article of 1989 reports ‘the Pesut’ as a new kind of dolphin. I regret that I don’t have the complete citation for this article; in my wisdom I clipped the date and other details at some point. Readers with exceptional memories might recognise the photo at upper right as the inspiration for a SpecZoo-themed piece of art…
Today, the Pesut isn’t regarded as a distinct species, but a local variant of the Irrawaddy dolphin Orcaella brevirostris. It’s known locally as the Pesut Mahakam, more formally as the Mahakam River dolphin, and is seemingly – with the rest of the Orcaella dolphins – an early-diverging member of the globicephaline clade (McGowen et al. 2009, Vilstrup et al. 2011), otherwise known for including killer whales, pilot whales and kin, the ‘blackfish’ [UPDATE: killer whales no longer appear to be part of Globicephalinae; see comments]. Pelletier’s proposal that the Mahakam River Orcaella population might be distinct is odd, since anyone familiar with the historical taxonomy of Orcaella knows (or should have known, even in 1989) that Pesut Mahakam is a local name for some riverine populatons of O. brevirostris (Marsh et al. 1989). Furthermore, there’s a long history of riverine Orcaella populations being considered distinct and of having their taxonomic status tested and re-evaluated.
Caption: an Irrawaddy dolphin photographed in Cambodia. Image: Stefan Brending, CC BY-SA 3.0 (original here).
Whatever, the Pesut does look kinda unusual. Books on whales very often say or imply that the Boto or Amazon river dolphin Inia geoffrensis and Beluga Delphinapterus leucas are the only two living cetaceans with an especially mobile neck, but this very probably isn’t true and Pesuts are often shown with the head being held at an obvious angle relative to the body. Other weird features that make the Pesut ‘extreme’ are its globular, short-snouted face and smiling mouthline, and the crease that runs along part of its dorsal midline.
Caption: an effort to portray an Irrawaddy dolphin in life. This dolphin can reach 2.75 m in length, males being larger. Image: Darren Naish.
If you know anything about cetaceans you’ll be aware of the fact that the Irrawaddy dolphin is superficially similar to the Beluga, and it’s this similarity which has led to the occasional suggestion that Orcaella might not be a dolphin but a tropical member of the same family as the Beluga (Monodontidae). This isn’t a ridiculous idea, but it isn’t supported by the detailed anatomy of this animal, or by molecular data.
Caption: I said the montage would become increasingly cluttered. And we’re not done yet. Image: Darren Naish.
And that’s where we’ll end things for now; the next article in the series will appear soon. And I’ll publish a lot more on whales here in the future. Here’s some of the stuff that exists in the archives (as always, much of the material at TetZoo versions 2 and 3 has been ruined by the removal of images, so I’m linking to wayback machine versions)…
A 6 ton model, and a baby that puts on 90 kg a day: rorquals part I, October 2006
From cigar to elongated, bloated tadpole: rorquals part II, October 2006
Lunging is expensive, jaws can be noisy, and what’s with the asymmetry? Rorquals part III, October 2006
On identifying a dolphin skull, July 2008
Seriously frickin' weird cetacean skulls: Kogia, shark-mouthed horror, July 2008
Scaphokogia!, July 2008
Cetacean Heresies: How the Chromatic Truthometer Busts the Monochromatic Paradigm, April 2015
Whale Watching in the Bay of Biscay, August 2019
Extreme Cetaceans, Part 1, September 2019
Extreme Cetaceans, Part 2, September 2019
Refs - -
Dixon, D. 1981. After Man: A Zoology of the Future. Granada, London.
Marsh, H., Lloze, R., Heinsohn, G. E. & Kasuya, T. 1989. Irrawady dolphin Orcaella brevirostris (Gray, 1866). In Ridgway, S. H. & Harrison, R. (eds) Handbook of Marine Mammals Volume 4. Academic Press (London), pp. 101-118.
McGowen, M. R., Spaulding, M., Gatesy, J. 2009. Divergence date estimation and a comprehensive molecular tree of extant cetaceans. Molecular Phylogenetics and Evolution 53, 891-906.
Naish, D. 1996. Ancient whales, sea serpents and nessies part 2: theorising on survival. Animals & Men 10, 13-21.
Vilstrup, J. T., Ho, S. Y., Foote, A. D., Morin, P. A., Kreb, D., Krützen, M., Parra, G. J., Robertson, K. M., de Stephanis, R., Verborgh, P., Willerslev, E., Orlando, L. & Gilbert, M. T. P. 2011. Mitogenomic phylogenetic analyses of the Delphinidae with an emphasis on the Globicephalinae. BMC Evolutionary Biology 11: 65.
Extreme Cetaceans, Part 2
Recall the recent article about ‘extreme cetaceans’? Well, here’s the second one in the series.
Spectacled porpoise. Porpoises – the seven* species of the delphinoid family Phocoenidae – are small, short-beaked cetaceans that mostly live fairly cryptic lives in shallow coastal seas (this description applies to the living species: some fossil porpoises were comparatively large and long-beaked). The species that typifies the group – the Harbour porpoise Phocoena phocoena – is greyish (except for its white belly), has a low, triangular dorsal fin and is not especially charismatic.
* I’ve followed recent taxonomic decisions and am recognising two species within Neophocaena (N. phocaenoides and N. asiaeorientalis).
Caption: Phocoena phocoena, the archtypical member of Phocoenidae. Image: Erik Christensen, CC BY-SA 3.0 (original here).
But other porpoises are rather different, and here we’re going to look at a far more flamboyant species, namely the Spectacled porpoise P. dioptrica of the cool and cold waters of the sub-Antarctic and Antarctic seas. This is a very poorly known species, and one of the things said about it most often is that just about nothing is known about it. It’s a 20th century discovery, its scientific debut occurring in 1912.
This species is remarkably pigmented relative to other Phocoena porpoises, being black dorsally, white ventrally, and with dark circles around its eyes. There have actually been a bunch of competing ideas on its exact appearance over the years, authors and artists disagreeing with respect to where the boundary between its dark and white areas are, what colour its flippers and tail flukes are, and so on. It’s distinct enough from the other Phocoena species that some authors have preferred to keep it in its own genus (Australophocoena), but this isn’t fashionable at the moment due to molecular data on its phylogenetic position. The suggestion has even been made that its pattern and colouring give it the ability to mimic killer whales and thus avoid predation. Cool idea, buuuut…. unlikely given that porpoises are so distinct from killer whales in size and surely in vocalisations and in the echolocatory signature that predatory cetaceans use when evaluating potential prey.
Caption: Spectacled porpoises photographed in the wild, in the Southern Ocean, in 2001. A male is at back, an adult female is closest to us, and a calf is in the middle. Image: Sekiguchi et al. (2006).
The Spectacled porpoise isn’t just remarkable for its pigmentation, however, but also for its shape, and in particular for its dorsal fin. This is ‘normal’ in some individuals, but disproportionally large – strangely so – in some individuals where it looks like an out-sized rounded flag projecting upwards and backwards at a size about twice or three times that you might predict. Like the keels, humps and unusual dorsal fins of some spinner dolphins (see the previous article in this series), this is a sexually dimorphic feature that’s especially exaggerated in mature males. Its presence is therefore presumably a sociosexual indicator of age and sexual status. Another odd thing about the dorsal fin (albeit one not unique to this species within porpoises as a whole) is that there are tiny tubercles along the leading edge (Evans et al. 2001), albeit seemingly not in all individuals. Dorsal fin tubercles are actually known for all porpoises – they’re weird and interesting and I’ll try to remember to come back to them in another article.
Caption: male, female and juvenile Spectacled porpoise, as illustrated by Uko Gorter for Natalie et al. (2018). The remarkable size of the male’s dorsal fin is obvious. Image: (c) Uko Gorter/Natalie et al. (2018).
This giant dorsal fin isn’t a newly discovered feature – it was reported and illustrated as far back as 1916 (Bruch 1916) – but it hasn’t ben commented upon as often as it might, especially given that it’s one of the most pronounced expressions of sexual dimorphism in cetaceans. Indeed, as Ellis (1983) noted, “only the killer whale manifests such a difference in the dorsal fin” (p. 198); sexual dimorphism of the dorsal fin is known in other porpoises, but isn’t as extreme as it is here (Torre et al. 2014). Apart from the fact that it’s obvious, and looks fairly absurd in the older males that have it, we don’t know much about this fin or its function. Maybe it’s ‘just’ a visual signal of sex, maturity and (perhaps) health and condition. Maybe – recall the comments in the previous article about dorsal fins functioning as thermal windows – it also plays an important physiological role. Whatever it does, it makes this an ‘extreme’ cetacean; an animal that looks surprising, weird and flamboyant.
Caption: I’m going to build a montage of the extreme cetaceans discussed in this series. This image will become more cluttered over time. Image: Darren Naish.
Finally — there’s a adoption scheme for the Spectacled porpoise. Adopt one yourself and aid in the conservation of this poorly known species.
More in this series soon. Here’s some of the stuff on cetaceans that exists in the archives (as always, much of the material at TetZoo versions 2 and 3 has been ruined by the removal of images, though remember that much or all of this is archived at Wayback Machine)…
A 6 ton model, and a baby that puts on 90 kg a day: rorquals part I, October 2006
From cigar to elongated, bloated tadpole: rorquals part II, October 2006
Lunging is expensive, jaws can be noisy, and what’s with the asymmetry? Rorquals part III, October 2006
On identifying a dolphin skull, July 2008 (all images now missing)
Seriously frickin' weird cetacean skulls: Kogia, shark-mouthed horror, July 2008 (all images now missing)
Scaphokogia!, July 2008 (all images now missing)
Cetacean Heresies: How the Chromatic Truthometer Busts the Monochromatic Paradigm, April 2015 (but now lacking all images)
Whale Watching in the Bay of Biscay, August 2019
Extreme Cetaceans, Part 1, September 2019
Refs - -
Bruch, C. 1916. El macho de Phocaena dioptrica Lah. Physis, 2461-2462.
Ellis, R. 1983. Dolphins and Porpoises. Robert Hale, London.
Evans, K., Kemper, C. & Hill, M. 2001. First records of the Spectacled porpoise Phocoena dioptrica in continental Australian waters. Marine Mammal Science 17, 161-170.
Natalie, R., Goodall, P. & Brownell, R. L. 2018. Spectacled Porpoise. In Würsig, B., Thewissen, J B. M. & Kovacs, K. (eds) Encyclopedia of Marine Mammals, Academic Press, pp. 912-916.
Sekiguchi, K., Olavarría, C., Morse, L., Olson, P., Ensor, P., Matsuoka, K., Pitman, R., Findlay, K. & Gorter, U. 2006. The spectacled porpoise (Phocoena dioptrica) in Antarctic waters. Journal of Cetacean Research and Management 8, 265-271.
Torre, J., Vidal, O. & Brownell, R. L. 2014. Sexual dimorphism and developmental patterns in the external morphology of the vaquita, Phocoena sinus. Marine Mammal Science 30, 1285-1296.
Extreme Cetaceans, Part 1
It was while going through my read all the books on the whales of the world phase of the early 1990s, I remember, that I first read of the dolphins – members of the highly streamlined, long-beaked, oceanic dolphin group no less – that have such weird features as deep keels, humps on the back and tailstock, and non-streamlined, forward-canted dorsal fins. Yes, we all know that whales are streamlined, torpedo-shaped animals with sensibly shaped appendages, but they’re not all like this. Quite a few species are weird, possessing anatomical specialisations and peculiarities that are counter-intuitive and little discussed, and most likely related to an unusual ecology, physiological regime, feeding strategy or social or sexual life.
Caption: a nice, normal looking group of Spinner dolphins. The obvious dark cape and paler side regions make these look like Hawaiian spinners but they were apparently photographed in the Red Sea. Image: Alexander Vasenin, CC BY-SA 3.0, wikipedia (original here).
In this short series of articles – yeah, this is Part 1 – I want to talk about just a few such animals, and I hope you’ll be as surprised by their anatomy and specialisations as I was when I first learnt about them.
Extreme spinners. Everybody knows that dolphins are streamlined, and the oceanic long-beaked dolphins (those conventionally united in the genus Stenella) are streamlined the most. The Spinner S. longirostris – a species that occurs throughout the tropical and subtropical marine waters of the world – is one such animal, its very long beak, torpedo-shaped body and tailstock and well-proportioned fins all appearing like textbook adaptations for swift movement in the pelagic environment. Yet for all this, some spinner dolphins – some specific individuals belonging to some specific populations – are very odd indeed.
Caption: one of the very best depictions of an ‘extreme’ male Eastern spinner is this one, from Shirahai & Jarrett’s 2006 Whales, Dolphins and Seals. Image: (c) Brett Jarrett.
These animals have arching dorsal humps and massive, bulbous ventral convexities on the tailstock which give them a peculiarly asymmetrical, lumpy appearance, the dorsal fin is not recurved and falcate, but has a straight or even concave anterior margin such that it might even lean forwards, and the tail flukes turn upwards at their outer edges. The exaggerated lump on the lower surface of the tailstock has a name: it’s the post-anal hump. This structure isn’t unique to the Spinner but is also present in other delphinids, like the Delphinus species. It appears to be sexually dimorphic and is especially prominent in mature males (Ngqulana et al. 2017). Perrin & Mesnick (2003) argued that these features - which are variable in spinner populations and most strongly developed in the so-called Eastern and Whitebelly spinners - are linked to testis size and to a polygynous mating system where males need to be highly distinct from their many female consorts, and built to display against, and fight with, other males. In other words, the most ‘extreme’ spinners are the most polygynous.
Caption: adult males differ in appearance across spinner populations, and it seems that the most ‘extreme’ males are those from the most polygynous populations. This diagram (from Perrin & Mesnick 2003) shows - from top to bottom - male Hawaiian, Eastern and ‘whitebelly’ spinners. Image: Perrin & Mesnick (2003).
How and why might this remarkable feature have originated? Spinners and other cetaceans adopt a sinuous, vaguely S-shaped profile when displaying to one another (this has now been seen in diverse cetaceans, mysticetes as well as odontocetes; Helweg et al. 1992, Horback et al. 2010), and one suggestion is that the post-anal hump and a matching convexity on the dorsal surface of the tailstock might serve to accentuate the curves of the S and thereby function in exaggerating this signal. One idea about the S-shaped pose is that it functions in shark mimicry (Norris et al. 1985; some sharks also adopt an S-shaped profile and use it to signal aggressive intentions), but the fact that it’s as widespread in cetaceans as it is – and similar poses are seen in other aquatic vertebrates – indicates that any similarities with non-cetaceans are convergent.
Caption: S-shaped postures, depicted (sometimes schematically) in cetaceans of very different sizes and proportions, from Horback et al. (2010). (A) Spinner dolphin, (B) Beluga, (C) Humpback whale. Evolve dorsal and ventral convexities on the body and tailstock, and you can exaggerate the intensity of this signal. Image: Horback et al. (2010).
Anyway… the features discussed here appear intuitively odd because they’re just about the opposite of what you’d predict to be present in a fast-swimming, pelagic predator which has otherwise evolved to be ultra-streamlined. But there you are.
Caption: humpback dolphins are not especially well known, and even less well known is that they’re kept in captivity in a few places and have been trained to do tricks. This individual was photographed in captivity in Singapore. Image: Tolomea, CC BY 2.0, wikipedia (original here).
The humpback dolphins. Everyone’s heard of the Humpback whale Megaptera novaeangliae, but less well known is that there are dolphins with humps too, perhaps four species of them if you follow some studies of molecular variation within the group (the Indo-Pacific humpback dolphin Sousa chinensis, Australian humpback dolphin S. sahulensis, Atlantic humpback dolphin S. teuszii and Indian Ocean humpback dolphin S. plumbea). Superficially, Sousa dolphins look something like bottlenose dolphins (Tursiops), and like them they’re coastal animals that prey on diverse fishes and cephalopods. Unlike the Tursiops dolphins, the Sousa species have a long raised section – sitting dorsal to the neural spines and musculature of the back – that extends along the middle part of the dorsal surface. The dorsal fin sits on top of this hump.
Caption: comparatively few people know that there are dolphins with humps, but check it out. These are Tom Ritchie’s illustrations of Sousa dolphins, representing adult males identified by Watson (1981) as S. chinensis (above) and S. teuszii (below). Images: Watson 1981.
The function of this hump – if it has one – is not well studied and authors have mostly avoided mentioning the possibility that it might have one. Does it function as a visual or acoustic signal of maturity? Does it have some role in buoyancy, hydrodynamics or streamlining? Is it a fat store? The dorsal fins of at least some cetaceans appear to function as so-called thermal windows: as heat-dumping structures, the large and extensive blood vessels of which carry cooled blood to the body interior (Meagher et al. 2002). In males, this cool blood helps lower the temperature of the deeply internal testes (Pabst et al. 1995), which might otherwise be prone to overheating. The humps of humpbacked dolphins, like the dorsal fins, appear to be richly innervated with blood vessels which again transport cooled blood from the animal’s exterior surface to deep within its body (Plön et al. 2018).
Caption: (A) vasculature in the dorsal fin and hump of a humpback dolphin compared with (B) dorsal fin vasculature in a Tursiops dolphin. The blood vessels in Tursiops are proportionally larger, but there’s a great number of them in the humpback dolphin, thanks to the hump. Image: Plön et al. 2018.
Could the hump therefore be a thermoregulatory specialisation for this mostly tropical group? Further research is needed, but this could be consistent with the fact that the hump is proportionally largest in adult males, and perhaps proportionally largest in those populations that inhabit the most tropical parts of Sousa’s entire range. A hydrodynamic role for the hump remains plausible but has yet to be investigated (Plön et al. 2018).
And that’s where we’ll end things for now. More in this series soon. I’ll publish a lot more on whales here in the future, but here’s some of the stuff that exists in the archives (as always, much of the material at TetZoo versions 2 and 3 has been ruined by the removal of images)…
A 6 ton model, and a baby that puts on 90 kg a day: rorquals part I, October 2006
From cigar to elongated, bloated tadpole: rorquals part II, October 2006
Lunging is expensive, jaws can be noisy, and what’s with the asymmetry? Rorquals part III, October 2006
On identifying a dolphin skull, July 2008 (all images now missing)
Seriously frickin' weird cetacean skulls: Kogia, shark-mouthed horror, July 2008 (all images now missing)
Scaphokogia!, July 2008 (all images now missing)
Cetacean Heresies: How the Chromatic Truthometer Busts the Monochromatic Paradigm, April 2015 (but now lacking all images)
Whale Watching in the Bay of Biscay, August 2019
Refs - -
Helweg, D. A., Bauer, G. B. & Herman, L. M. 1992. Observations of an S-shaped posture in humpback whales (Megaptera novaeangliae). Aquatic Mammals 18.3, 74-78.
Horback, K. M., Friedman, W. R. & Johnson, C. M. 2010. The occurrence and context of S-posture display by captive belugas (Delphinapterus leucas). International Journal of Comparative Psychology 23, 689-700.
Meagher, E. M., McLellan, W. A., Westgate, A. J., Wells, R. S., Frierson, D. Jr. & Pabst, D. A.. 2002. The relationship between heat flow and vasculature in the dorsal fin of wild bottlenose dolphins Tursiops truncatus. Journal of Experimental Biology 205, 3475-3486.
Pabst, D. A., Rommel, S. A., McLellan, W. A., Williams, T. M. & Rowles, T. K. 1995. Thermoregulation of the intra-abdominal testes of the bottlenose dolphin (Tursiops truncatus) during exercise. Journal of Experimental Biology 198, 221-226.
Norris, K. S., Wursig, B., Wells, R. S., Wursig, M., Brownlee, S. M., Johnson, C. & Solow, J. 1985. Behavior of the Hawaiian spinner dolphin, Stenella longirostris. National Marine Fisheries Service Administrative Report LJ-85-06C.
Ngqulana, S. G., Hofmeyr, G. J. G. & Plön, S. 2017. Sexual dimorphism in long-beaked common dolphins (Delphinus capensis) from KwaZulu-Natal, South Africa. Journal of Mammalogy 98, 1389-1399.
Perrin, W. F. & Mesnick, S. L. 2003. Sexual ecology of the Spinner dolphin, Stenella longirostris: geographic variation in mating system. Marine Mammal Science 19, 462-483.
Plön, S., Frainer, G., Wedderburn-Maxwell, A., Cliff, G. & Huggenberger, S. 2018. Dorsal fin and hump vascular anatomy in the Indo-Pacific humpback dolphin (Sousa plumbea) and the Indo-Pacific bottlenose dolphin (Tursiops aduncus). Marine Mammal Science 35, 684-695.
Whale Watching in the Bay of Biscay
Back in July 2019, myself and a bunch of friends stepped aboard the Pont-Aven for several days of sea-watching in the Bay of Biscay. We were to travel from Plymouth (UK) to Santander (Spain), the event being organised by ORCA, a charity that monitors whales and uses the data for conservation purposes (they’re here on Twitter). ORCA uses cruise liners, ferries and other vehicles as whale-watching platforms. Nigel Marven was a special guest on our trip and it was great to catch up with him.
Caption: our vessel of choice - the Pont-Aven - at port in Santander, Spain. I cannot tell you how much trouble I went to to get to this ship before departure time. I very nearly didn’t make it. Image: Darren Naish.
Caption: the man, the legend; Nigel Marven.
The purpose, of course, was to see whales. The weather was outstandingly good (meaning that I got burnt), but so was the whale watching: I’m pleased to say that we saw literally hundreds of animals of seven or eight species, as you can see from the photos below. My own photos are not great since my camera isn’t exactly the best for fast-moving, far-away animals like whales, so those you see here were mostly taken by my trusty pal Alex Srdic (who’s here on Instagram and here on Twitter). Thanks, Alex.
Caption: several cetaceans have extremely complex markings allowing them to be identified to species and even population. Individuals can be recognised on the basis of their markings too. Image: Alex Srdic.
The Bay of Biscay is a world-famous whale-watching hotspot, famous in particular for Cuvier’s beaked whales Ziphius cavirostris and Sperm whale Physeter macrocephalus. Dolphins of several species are a frequent sight too, as are rorquals of a few species, Harbour porpoise Phocoena phocoena and pilot whales. A very lucky whale-watcher might get to see Blue whale Balaenoptera musculus, Killer whale Orcinus orca or True’s beaked whale Mesoplodon mirus. In fact, something like 30 species have been recorded in the region. This is phenomenal and mean that it’s theoretically possible for several species of some of the most elusive whale groups – like beaked whales and globicephaline dolphins – to be seen within days or weeks of each other.
Caption: in good weather, the blow of a big whale (like a Fin whale - as here - or a Sperm whale) is visible from great distance, and in the case of these two species can be diagnostic. Image: Alex Srdic.
Caption: a dynamic leap by a Striped dolphin. Dolphins of some species appear to be attracted to ships and even to deliberately show off when they get close to them. Image: Alex Srdic.
Why is the Bay of Biscay so good for whales? It’s mostly because the topography is complex, combining large, shallow shelf regions, steep sections of shelf edge – sometimes with impressive slopes and deep, enormous rocky canyons twice as big as the Grand Canyon – and a deep abyssal plain section (Carwardine 2016). Depth varies from 1.7 to over 4.7 km. This variation – combined with the overall productivity of the region and its position relative to the Atlantic and English Channel – means that there’s the chance to see continental shelf species (like porpoises), those that use deep canyons and other shelf-edge habitats (like beaked whales) and true oceanic deep-divers that forage in the deepest waters (like sperm whales).
Caption: back and dorsal fin of a Fin whale, remnants of the blow still hanging in the air. Image: Alex Srdic.
As it happens, we were extraordinarily lucky. Fin whales B. physalus are regular animals of the area, and we had amazing, relatively close views of them (by ‘close’, I mean perhaps 30 m from the ship, not alongside the vessel). Fin whales – the second largest extant animal after the Blue – have a blow that’s visible on the horizon and is about 8 m tall. The blow hangs in the air for a surprising time. One of the most remarkable things about the Fin whale is its asymmetrical pigmentation: the right side of the face is marked with a large pale area, as is the right side’s baleen. There are some old TetZoo articles on what this might mean and how it might function – see the links below.
Caption: excellent view of the splashguard - the conical structure surrounding and ahead of the blowholes - and paired blowholes of a surfacing Fin whale. Despite its name, the dorsal fin of the Fin whale is smaller and blunter than that of some other rorquals. Image: Alex Srdic.
Two coastal species were seen early on in our trip: Harbour porpoise and Common bottlenose dolphins Tursiops truncatus, though I don’t have good photos of either. The majority of dolphins seen on our trip (as is typical for Biscay whale watching) were Short-beaked common dolphin Delphinus delphis, which were sometimes seen in groups of more than ten. Their distinctive hourglass markings are always visible when they leap – which they often do, sometimes while immediately adjacent to a ship – and we also got to see calves on one or two occasions.
Caption: here’s the whole-body view of the common dolphin shown in detail above. This individual only has one stripe extending from the beak to the flipper, with a large pale area separating the eye and flipper. Different configurations are present in different populations. Image: Alex Srdic.
Caption: as the light begins to fade during the later part of the day, a group of Short-beaked common dolphin carve through a surging wave. Note the calf close to the adult at upper right. Image: Alex Srdic.
We also had excellent views of Striped dolphin Stenella coeruleoalba. They behaved in characteristic acrobatic fashion, leaping high out of the water, making impressive splashes and jumping in the ship’s wake. They typically make a lot more disturbance at the water’s surface than do common dolphins, creating great bursts of spray and rooster-tail patterns when they leap and surge. Striped dolphins are near-globally distributed. They’ve been the source of discussion lately since it’s recently been shown that the Clymene dolphin S. clymene is a naturally occurring hybrid between this species and the Spinner S. longirostris (Amaral et al. 2014).
Caption: we had many excellent views of high-leaping Striped dolphin. Note how much spray and splashing is associated with the leaping of this species. Image: Alex Srdic.
Finally as goes dolphins, we also saw pilot whales, identified on the basis of their black colouration and strongly backswept dorsal fins. These were most likely Long-finned pilots Globicephala melas (it’s more typical of temperate and cold waters than the Short-finned G. macrorhynchus) but we didn’t see any of the key features that allow the two species to be distinguished, and none of our photos are good enough to warrant sharing. A mysterious whale was seen among the pilot whales. It seemed to be very dark and with a short, blunt-tipped, parallel-sided but only weakly curved dorsal fin; I don’t think that its head was seen but I had the impression that it was a shallower-bodied animal than the pilot whales. Several different views were offered on its identity with the most likely (on the basis of dorsal fin shape) being that it was perhaps a False killer whale Pseudorca crassidens. That’s not tremendously likely but not impossible.
The whale most famously associated with the Bay of Biscay is Cuvier’s beaked whale, seen so frequently in the area that it’s regarded as the premier location for sightings of this species, worldwide. I don’t know if you’re guaranteed a sighting of a Cuvier’s while there, but – whatever – we were lucky, since we saw nearly 20 of them, ranging from smooth, clean-bodied youngsters to heavily scarred males.
Caption: Cuvier’s beaked whale, seen relatively close to the ship. Image: Alex Srdic.
Caption: heavily scarred Cuvier’s beaked whale, seen at distance and only briefly. We didn’t see any other individuals with scarring as impressive as this. Image: Alex Srdic.
Some individuals have markedly pale heads sharply demarcated from the rest of the body, others do not. On occasion, one or two individuals were close enough to the ship that I was able to get a half-decent shot with my mobile phone. Each sighting was a huge thrill. While we were oh so lucky as goes Cuvier’s, we didn’t see sperm whale, alas. We also saw Northern minke B. acutorostrata on perhaps two occasions, though again I don’t have any good photos.
Caption: another plus… amazing sunsets, and sunrises too. Image: Darren Naish.
Finally, we didn’t just see whales. The same route is also great for seabirds, and we also saw such fishes as tunas and sunfishes. As much as I’d like to start talking about the birds, I’m out of time. Anyway – the trip was excellent: rewarding, fun, and educational. I’ll definitely be doing it again. You should consider supporting ORCA and their work as well.
Cetaceans have been covered at length on TetZoo before - mostly at ver 2 and ver 3 - but these articles are now all but useless since all of their images have been removed (and/or they’re paywalled, thanks SciAm). Over time, I aim to build up a large number of cetacean-themed articles here at ver 4.
A 6 ton model, and a baby that puts on 90 kg a day: rorquals part I, October 2006
From cigar to elongated, bloated tadpole: rorquals part II, October 2006
Lunging is expensive, jaws can be noisy, and what’s with the asymmetry? Rorquals part III, October 2006
On identifying a dolphin skull, July 2008 (all images now missing)
Seriously frickin' weird cetacean skulls: Kogia, shark-mouthed horror, July 2008 (all images now missing)
Scaphokogia!, July 2008 (all images now missing)
Cetacean Heresies: How the Chromatic Truthometer Busts the Monochromatic Paradigm, April 2015 (but now lacking all images)
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