Ian McTaggart Cowan

Chapter 22: Coastal Islands 1939

“Our observations tend to support the theory that colonization was by means of huge rafts of logs and debris…”

– Ian McTaggart Cowan

The Cowans headed up the coast June 24th, 1939 to meet Tom and Elinor McCabe and Pat Martin for a proposed two-month biological survey of British Columbia’s coastal islands north of Queen Charlotte Sound. Ian and Joyce had grown close to the McCabes during their honeymoon at Indianpoint Lake and time with them in Berkeley. Cowan was keen to implement their plans to figure out the distribution of birds and mammals along the central BC coast. Their survey included over 25 islands and mainland survey areas. Cowan was intrigued with this convoluted archipelago and coastline from an evolutionary point of view, “separated by many miles of tortuous, precipitous coast in which several rivers and many extensive inlets penetrate from the humid outer coast climate to a less humid inland climate.” There were two objectives: a survey of ocean-going birds, which required being on the outside coast and finding safe anchorages; and determining the evolutionary effects of isolated islands on small mammal populations. Both could be found at their first stop – Spider Island. One of the enigmas they encountered was two species of shrew: the coastal variety of the Common Shrew which displayed “remarkable uniformity” ; and the Dusky Shrew, Sorex obscurus, which had confusing variations even between neighbouring islands, and suggested evolution through speciation was well underway. Darwin had his finches but Cowan was fascinated by his non-flying shrews!

Red-legged frog

Cowan again seemed to have an uncanny ability to home in on interesting biodiversity and evolutionary hotspots. In 1939 these major archaeological and paleoecological discoveries were still 70 years away, so all he had to go on was the puzzle of the shrews. To that end he spent a lot of time watching where they foraged, what they ate and how they interacted with the sea. Cowan was on to something again. Insectivores have recently taken the limelight in their role in surviving another major global event – the mass extinction from the asteroid impact 65 million years ago at the Chicxulub Crater in Yucatán, which wiped out the dinosaurs and everything else that wasn’t under the soil or water. Humans have a lot to be grateful to shrews for, specifically our existence, because these early insectivores are the common ancestor from which all mammals repopulated the earth.

His entries include spotting seabirds like Marbled Murrelets from a rolling deck, crawling through a bog to see the skittish Red-throated Loons nesting, and following Canadian Sandhill Cranes “running like rabbits” up forest trails to their nesting sites in the bogs. The Canadian subspecies were so named because early American ornithologists knew only that these birds disappeared somewhere in Canada to breed. Cowan suspected that these island cranes might be a distinct population again. It was difficult to do any kind of taxonomy, though, as the cranes were rare, scarce and nervous. They had been one of the species heavily targeted by milliners for their showy feathers at the turn of the century, causing their populations to drop perilously low. The cranes were only just beginning to recover, aided by the remoteness of their breeding habitat. 

Ian McTaggart-Cowan species index (1939-1942): birds

They are a fascinating species to ornithologists for their antiquity. Fossil remains of cranes nine million years old are relatively indistinguishable from the modern species, making this one of the world’s oldest bird species. It also makes them a haunting animal to come across, with their prehistoric call and gait, about which Leopold wrote in a lesson to the “B”: “the crane is wildness incarnate.” The distinctive behaviour of the coastal cranes running up to breeding bogs led Cowan to suspect that the birds were well adapted to the specific geography of coastal islands. By the time he was involved in writing Birds of BC in the late 1980s, work still had not been done on this population. Keen to encourage research into this unique population of cranes, he acted as an adviser (at age 96) to the Raincoast Conservation Foundation. Of the seabirds, he was very interested in their foraging behavior and food as little was known about that or the relationship of food to their reproductive success.

Upon returning to Victoria, Ian and Joyce Cowan were to have their own reproductive success. In characteristic fashion, Cowan mentions little of his domestic situation but kept a herpetological journal charting the final demise of a Red-legged Frog that had been in the museum for almost as long as some of the staff:

On May 4, 1940, the frog was weakening noticeably and could no longer elevate itself or its legs and moved very little. In June it became necessary to place food in its mouth before it would feed. The frog died July 9, 1940, at the venerable age of approximately fifteen years, thirteen of which were passed in captivity.

Ian McTaggart- Cowan species index (1939-1942): mammals

In the spirit of the indomitable cycles of life, the Cowans’ son, Garry McTaggart Cowan, was born the very same day. Garry was Rh negative, like Joyce, and so this baby, at just over 6 pounds, was happily going to survive. The newspaper birth announcement stated: “Both doing well.”

An earlier trip to Berkeley had set some ideas in motion for Cowan. He missed the stimulation of a local academic community and was offered a position at UBC in his old department. There were three further considerations: Cowan’s old roommate William Kaye Lamb, the provincial archivist, had also accepted a position at UBC; Cowan’s salary at the university was likely to improve over time; and finally, Joyce would be close to her family and have help with the new baby.

As a footnote, Spider Island was selected shortly after their expedition by the RCAF as a Pacific early-warning radar installation and communications station. Interestingly, the lack of information in the museum files about these expeditions may have had some strategic reason, although there is no hard evidence for this. If some secret military reconnaissance work needed a research cover story, pelagic birds and island evolution were an excellent choice. 

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