The Marbled Murrelet is a small auk that lives along the West Coast of North America from California to Alaska. It is a seabird related to the murre and puffin but unlike its larger relatives that breed in huge colonies on small offshore islands, it nests by itself on the mainland. These unusual habits made it one of the most obscure birds in North America until a nest was finally discovered in 1974. It had kept its nest site a secret longer than any other North American bird.
The discovery of the first murrelet nest was a watershed moment for the species. Not only did it resolve a long-standing mystery, but, it launched the murrelet as a flagship species for forest-bird conservation issues. The nest was found in an old-growth Douglas fir at a time when environmental NGOs were trying to awaken the public to the disappearance of coastal old-growth forests. Unfortunately the bird’s long period in obscurity left conservation biologists scrambling to understand its life cycle and habitat requirements. Between 1980 and 1999, many millions of dollars were spent in Canada and the U.S. to determine the exact nature of the forests that murrelets chose for breeding.
The long period of obscurity, the species’ limited range, at its later notoriety as an icon of the old-growth forest controversies has made the murrelet popular with visiting naturalists. Kaiser has tried to keep their interests in mind and provide details that enrich their observations by explaining the causes and significance the bird’s behaviour.
Much of this book describes research projects on the Marbled Murrelet that took place in British Columbia. It is largely a personal memoir, so it focuses on studies that Kaiser led and found funding for. It begins by describing coastal surveys that revealed nothing about the preferred types of forests but did give biologists a rough idea of the murrelet’s seasonal distribution. It quickly moves to technology-based projects that not only provided very specific pieces of information but made the murrelet as well known as almost any other species. Radio-telemetry followed the local movement of birds and provided very specific information on individual nests. Blood sampling identified the sex of individuals and gave specific information about their breeding status. Radar tracking produced accurate estimates of bird numbers and precise estimates of flight speed.
We can now see the murrelet as one of the most amazing birds on the west coast. Its habit of nesting in trees was only the thin edge of the wedge. It flies faster than any other species on the coast and carries a very heavy egg further and to higher elevations than any other species. For a month or so it carries heavy loads of fish between marine foraging areas and a nestling waiting as much as 100 km inland and it does so through mist, fog, cloud, rain, and even unseasonal snow. During hours of absolute darkness, it finds the right branch in a forest of branches.
A species with such an extreme degree of energy consumption as the murrelet is always at risk if conditions change. The murrelet fuels its performance by eating calorie-rich fish that are sensitive to temperature changes in seawater. These fish are also affected by the presence of petroleum products and their calorie density makes them a tempting target for suppliers of food for fish farms and pets.
We now know that the murrelet has much more diverse habitat preferences than previously expected and that it remains abundant, particularly in the fiords of the northern part of its range. That does not mean that we can relax our vigilance over the loss of old-growth forest, the problems of climate change, or increased risk from oil spills or other industrial activity.