GRAY WHALES: ESCHRICHTIUS ROBUSTUS

Young Gray Whale, Eschrichtius robustus

The lovely fellow you see here is a young Gray Whale, Eschrichtius robustus, with a wee dusting of barnacles and his mouth ajar just enough to show his baleen.

Two Pacific Ocean populations are known to exist: one of about 200 individuals whose migratory route is presumed to be between the Sea of Okhotsk off Russia's south coast and southern Korea, and a larger one with a population of about 27,000 individuals in the eastern Pacific.

This second group are the ones we see off the shores of British Columbia as they travel the waters from northernmost Alaska down to Baja California. Gray whale mothers make this journey accompanied by their calves, hugging the shore in shallow kelp beds and providing rare but welcome glimpses of this beauty.

The gray whale is traditionally placed as the only living species in its genus and family, Eschrichtius and Eschrichtiidae, but an extinct species was discovered and placed in the genus in 2017 — the Akishima whale, E. akishimaensis. Some recent DNA analyses suggest that certain rorquals of the family Balaenopteridae, such as the humpback whale, Megaptera novaeangliae, and fin whale, Balaenoptera physalus, are more closely related to the gray whale than they are to some other rorquals, such as minke. Still, others place gray whales as outside the rorqual clade, a kissing cousin if you will.

John Edward Gray placed it in its own genus in 1865, naming it in honour of physician and zoologist Daniel Frederik Eschricht. The common name of the whale comes from its colouration. The subfossil remains of now-extinct gray whales from the Atlantic coasts of England and Sweden were used by Gray to make the first scientific description of a species then surviving only in Pacific waters. The living Pacific species was described by American palaeontologist, Edward Drinker Cope as Rhachianectes glaucus in 1869.

Fin Whale, Balaenoptera physalus

Skeletal comparisons showed the Pacific species to be identical to the Atlantic remains in the 1930s, and Gray's naming has been generally accepted since. Although identity between the Atlantic and Pacific populations cannot be proven by anatomical data, its skeleton is distinctive and easy to distinguish from that of all other living whales.

In 1993, a twenty-seven million-year-old specimen was discovered in deposits in Washington state that represents a new species of early baleen whale. It is especially interesting as it is from a stage in the group’s evolutionary history when baleen whales transitioned from having teeth to filtering food with baleen bristles.

Visiting researcher Carlos Mauricio Peredo studied the fossil whale remains, publishing his research to solidify Sitsqwayk cornishorum (pronounced sits-quake) in the annals of history. The earliest baleen whales clearly had teeth, and clearly still used them. Modern baleen whales have no teeth and have instead evolved baleen plates for filter feeding. Look to the rather good close-up of this young Gray Whale here to see his baleen where once there was a toothy grin.

The baleen is the comb-like strainer that sits on the upper jaw of baleen whales and is used to filter food. We have to ponder when this evolutionary change —moving from teeth to baleen — occurred and what factors might have caused it. Traditionally, we have sought answers about the evolution of baleen whales by turning to two extinct groups: the aetiocetids and the eomysticetids.

The aetiocetids are small baleen whales that still have teeth, but they are very small, and it remains uncertain whether or not they used their teeth. In contrast, the eomysticetids are about the size of an adult Minke Whale and seem to have been much more akin to modern baleen whales; though it’s not certain if they had baleen. Baleen typically does not preserve in the fossil record being soft tissue; generally, only hard tissue, bones and teeth are fossilized.

SQUIRRELS: SHADOW TAILS

One of the little animals I see daily in Kitsilano, Vancouver, are the very busy, highly comic rodents we know as squirrels. 

They spend their days busily gathering and caching food and their nights resting from all that hard work. 

My neighbourhood has mostly Eastern Gray squirrels, Sciurus carolinensis (Gmelin, 1788) who come in a colour palette of reddish-brown, grey (British spelling) and black. 

These cuties have bushy tails and a spring in their step — racing around gathering nuts, finding secret hiding spots to cache them, teasing dogs and generally exuding cuteness.

We find the first fossil evidence of tree squirrels in the Pleistocene. At least twenty specimens have been found of Sciurus carolinensis in Pleistocene outcrops in Florida on the eastern coast of the United States. Over time, their body size grew larger then shrunk down to the 400 to 600 g (14 to 21 oz) weight we see them today.  

Eastern Gray squirrels have two breeding seasons in December-January and June-July. This year has been unseasonably warm. On Vancouver Island, the Eastern Grays bred again in early September. One wonders if the heat dome killed off the July litter, and with the return of more favourable weather, the parents have been induced to breed again.

While they are not native to Vancouver, they are plentiful. They were introduced to the region over a hundred years ago and have been happily multiplying year upon year. 

Our native species are the smaller, reddish-brown, rather shy Douglas squirrels, Tamiasciurus douglasii (Bachman, 1839), and the nocturnal Northern Flying Squirrels, Glaucomys sabrinus (Shaw, 1801).  

Sciurus, is derived from two Greek words, skia, meaning shadow, and oura, meaning tail. The name choice is poetic, alluding to squirrels sitting in the shadow of their tails. 

The specific epithet, carolinensis, refers to the Carolinas on the eastern seaboard of the United States, an area that includes both North and South Carolina. It was here that the species was first recorded and still rather common. In the United Kingdom and Canada, Sciurus carolinensis is referred to as the Eastern Gray or grey squirrel — and though adorable is an invasive species. 

In the United States, Eastern is used to differentiate the species from the Western Gray or Silver-Gray squirrel, Sciurus griseus, (Ord, 1818). 

The Ord here, of course, is George Ord, the American zoologist who named the species based on notes recorded by Lewis and Clark in the early 1800s. If you fancy a read, check out his article from 1815, "Zoology of North America." It is charming, anachronistic and the first systemic zoology of America by an American. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, use the word ta̱minasux̱, to express: "that is a squirrel." 

The word for shadow in Kwak'wala is gagumas and tail is ha̱t̕sa̱x̱ste' — so I will think of these wee wonders of the Order Rodentia in the family Sciuridae as the Gagumas ha̱t̕sa̱x̱ste' of Khahtsahlano.