SpruceRoots Magazine - September 2001

 

TOO-WIT TOO-WOO

by Erica Thompson

Ever wonder about the biological catch phrase, 'sub-species'? Genetically distinct creatures, like the Queen Charlotte blackbear and the Queen Charlotte ermine, are celebrated and studied as living evidence of the Island's ancient story including the arrivals and departures of ice ages, continental and oceanic plates. Well, there is one a little quieter than the others, one who still manages to evade the bright eyes of scientific inquiry.

Cached in the wooden crevices of conifers, shrouded in mystery, lives a sub-species bearing the local geographic signature. This infamous recluse is the Queen Charlotte Saw-whet owl (Aegolius acadicus brooksi) which is said to be extraordinarily wary of people. The QC Saw-whet is a sub-species of the Northern Saw-whet and is found only on Haida Gwaii. It nests in abandoned cavities carved from snags by industrious woodpeckers and like its fashion of habitat, the

Saw-whet remains largely concealed from the scientific eye of researchers. Today, it finds a place amongst the British Columbia Conservation Data Centre's 'Blue-List' as a vulnerable species. Much of what we know about saw-whet owls in general is based upon the mainland Northern Saw-whet species and little information is available specifically about the QC Saw-whet. This absence of information is not in itself inherently dangerous but becomes so when forest habitat for island cavity nesters declines with the rate of cut. Without knowing the breeding, habitat and population dynamics of the owl, it is devilishly difficult to protect. Such information gaps in the biological record have been encouraging researchers to travel into the forest after dark searching for owl sign and song.

Owl conservationist, Rolf Krahe of the Smithers based Society for the Conservation and Research of Owls (SCRO), says of the Queen Charlotte Saw-whet, "almost all of its reproduction biology, food requirements, habitat demand, population number and density, along with its ability to adapt to a changing environment due to intensive logging practices, are still unknown. The Queen Charlotte Owl is the only breeding owl species on these islands and with such a small distribution range it is susceptible to rapid decline in numbers when changes occur to its environment, be they natural or man-made disasters. Therefore it is long overdue and urgent that we learn more about this owl to secure its place in a quickly changing and future world."

Throughout time, owls have fascinated people capturing imaginations in diverse and provocative ways. Owl species are at times identified as harbingers of death and gloom and venerated wise beings carrying the souls of people who have passed beyond us. It seems fitting that the Queen Charlotte Saw-whet is still mystifying those striving to learn more about their ways and means.

A snap shot of the creature's physical make up present very curious and downright bizarre images­observations akin to dreams or even nightmares. In Owls of North America, Allan Eckert confesses that one of the most peculiar and appealing characteristics of the Saw-whet owl, for him, "is the seemingly impossible positions into which it moves its head-sometimes with its chin virtually resting on its feet, sometimes with the face looking straight backward, as if the head had been put on a full 180 degrees off kilter, and even more startlingly, turning its head so amazingly that the eyes are below the beak as its stares balefully at an intruder."

The Queen Charlotte Saw-whet owl is a small owl similar in shape, size, weight and body composition to the mainland Northern Saw-whet which on average is the thirteenth smallest owl of the eighteen North American species. It lacks the characteristic ear tufts of many other owls and its rich plumage gives it a distinguished edge on its mainland Saw-whet relatives. The variation in plumage colouration is so striking some owl experts believe Haida Gwaii's Saw-whet may be not only a sub-species but also a different owl species altogether. Where the mainland owl is scattered with white spots on its nape, backside and underside, the Queen Charlotte owl is a strong light rufescent and bears more deep rich browns and has an orange buff underbelly. It sports thick feathering down its legs, feet and on its toes right down to its talons.

The Saw-whet's colouration blends well into the sun-dappled forest as it sits on its roost. Cannings notes, the owl is a prize fidgetter and stillness "is not always easy for the bird, for when awake it seems to have a difficult time sitting still; the head seems to want to bob, constantly, and the bird is continually swiveling its head to look in various directions with what appears to be un-limited curiosity."

In flight, the small body of the Saw-whet seems out of proportion with its broad wing span. When emerging from its hole, usually an abandoned woodpecker hole housed in a snag, the owl drops down to the forest floor, rapidly beating its wings to where it wants to fly, then ascends quickly again to perch. In flight, its short tail is rarely spread and in the tricky light of dusk, the Saw-whet can appear to some observers much like a big bat.

There appears to be little consensus in the 'owl community' over exactly which call of the Saw-whet's inspired the name. Cannings, in The Birds of North America, identifies nine distinct vocalizations belonging to the Northern Saw-whet owl. An advertising call, made up of a series of monotonous whistled notes of the same pitch, is said to be mostly used by males during courtship. This call is audible to the human ear up to 300 meters through the forest and one kilometer over water from the singing owl! A short rapid and soft series of whistled notes is commonly used by the male when approaching the nest with food, a nasal whine or wail, a high pitched 'tsst' made by females in response to the males advertising call. Nestlings make a 'chirruping' begging call, there is the short "insect-like buzz" heard during a threat display, a twittering call similar to the American woodcock and the short series of notes, usually three, of loud sharp squeaking calls, resembling "ksew-ksew-ksew" made by both sexes and often cited as the "Saw-whet" call.

Along with the ability to voice many different calls for different circumstances, the saw-whet like many other smaller owls, is somewhat of a ventriloquist. In the Owls of North America, Eckert describes a meeting with a voice throwing Saw-whet.

"The authors have actually watched one of these interesting little owls calling from a branch about twenty feet in front of us and yet both of us were utterly convinced for a time that another owl was calling, first from behind us, then off to the left, and finally from far ahead of us past the owl we were watching. It was only through associating the sounds we were hearing with the movements of the bird's beak as it sang that we were able to convince ourselves that the bird we were watching was the one who was doing all the singing.

Eckert goes on to say, one of the more pleasant calls for which the Saw-whet owl is noted is a very melodious, tinkling sound that can not be reproduced in print but which has "the remarkable quality of sounding almost exactly like a tricklet of water falling into a quiet little pool." Interestingly, it is said that the Montagnais people of Quebec believed that the Eastern Saw-whet owl was once the largest Owl in the world and was very proud of its voice. After the owl attempted to imitate the roar of a waterfall, the Great Spirit humiliated the Saw-whet owl by turning it into a tiny owl with a song that sounds like slowly dripping water.

* * *

Saw-whet owls are cavity nesters, dwelling in holes carved out of the dead wood of snags. Thirteen, of the twenty owl species in North America, and eight of the thirteen European owls depend on tree cavities for habitat and Saw-whets are among the approximately 90 species of vertebrates in British Columbia dependent upon wildlife trees for their survival. Considering so little is known about the elusive owl, it is challenging that we do know the standing dead wood, which cavity nesters depend upon, is becoming a rarer commodity on the landscape, especially in our managed second growth forests.

To delve deeper into the questions surrounding the world of the Queen Charlotte Saw-whet and its habitat preferences, Richard Cannings and Michael Gill took to the Island woods in 1996. Their after dark surveys took them into clearcuts, young forests, mixed aged 30-60 years of age, mature and old growth forests scattering the archipelago from Tow Hill to Datlamen Main, Yakoun Main, Tlell, Rennell Sound, Rennell Main, Deana West, Alliford Bay, Gray Bay and Peel Inlet. They established ten survey routes with a total of 238 survey stations on Graham and Moresby Islands.

Under the night sky, the researchers would use play a Saw-whet owl song from the roadside and hope for a response from a nearby owl. If an owl was heard singing before the recording was aired, off into the woods they hiked in search of the Saw-whet song tree. They were looking for a pattern or a correlation hidden amongst the combinations of variables like elevation, biogeoclimatic subzone, distance to the ocean, distance to the riparian zone, distance to a clearcut, forest age, aspect, percentage of shrub cover, canopy closure and snag density.

Their research documented 61 individual Saw-whets, five song trees, two of which were in mature forest and three in old growth forests. Their surveys did not reveal any Saw-whet nests.

Cannings and Gill's report says, "the results from the habitat analysis of survey sites show an interesting combination of habitat associations for Queen Charlotte Northern Saw-whet owls, that of older forests next to very young forests. Old forests may be attractive to the owls, since they need cavities for nesting and an open understory for hunting. Young forests may provide good roosting habitat, since this species roosts in thick vegetation, either near the ends of branches on large trees or near the trunks of small, densely growing trees."

* * *

If you have ever wondered, while wandering the trail which follows the Tlell River near Wiggins Road what the small boxes nailed to certain trees are for and who has put them there, the answer begins with the Saw-whet owl. The Queen Charlotte Owl Project is part of the efforts to protect the world's owl species by the Society for the Conservation and Research of Owls.

"So far we have 150 nest boxes in place and we tried to cover all kinds of habitats from old growth forest to second growth forest, clear cuts and in house gardens, along rivers, lakes and the ocean shoreline," says SCRO's executive director Rolf Krahe.

The use of nest boxes raises a dire question concerning species like the Queen Charlotte Black bear and the Saw-whet owl alike; the preservation of wildlife trees or more simply put, dens and cavities.

Krahe's journal notes taken during an outing searching for nest box sites sheds light on the differences in habitat qualities existent in old growth/mature forests and managed second growth areas.

"Our final day we hung boxes along the Port Main [road], in the area of the Golden Spruce trail. This small patch of old growth forest gives one a glimpse of another world before the advent of large-scale logging. Across the road, by the Yakoun Main, one sees a very different forest. This young second growth forest, which has been spaced and pruned, has a dense canopy with little undergrowth. Indeed, it is almost impossible to walk along the ground, rather one must very gingerly pick one's way along the thick layer of branches that cover the ground. As this is a second growth forest, there are no cavities in this forest. It is very unlikely that any cavity nesters will be located in this forest at present but it is hoped that by supplying the artificial cavities the cavity nesters, in particular the Saw-whet owl, can re-colonize this patch of forest from adjacent old growth forests."

The nest box project for the owls is a volunteer effort, from the construction of the boxes to their placement and subsequent monitoring for owl presence once in the forest. The nest boxes are artificial substitutes for tree cavities and according to Krahe, "we have to face the fact that the aim of today's forest managers is to create a forest which serves as a renewable resource for human consumption. That will be a forest, which has not too many old decaying trees in it and will be harvested regularly like a wheat field. The days where old decaying trees are standing side by side with younger trees are days of the past. Even selective logging is no solution to the tree cavity shortage because one takes out the older mature trees which have the size and age to become a nursery of an owl in the future."

The mystery long surrounding the Queen Charlotte owl may be at a diminishing point. This summer Laskeek Bay Conservation Society published observations of a nesting Saw-whet owl pair on Limestone Island. The Limestone Log reports, "the Northern Saw-whet owls are definitely nesting in Wildlife Tree One. At dusk, we frequently see the male fly in carrying food, briefly inserting his head inside the cavity then flying away. Occasionally, the female is observed with the head out of the cavity during the day." According to Krahe, this is spectacular news potentially represents the first documented breeding of the QC Saw-whet! The discovery of a nest can only promise to lead to new information­that is, if its sense of reclusivity remains under watchful eyes.

Photos: Owl - SRs staff / InHouse :: Owl Box - Rolf Krahe

SpruceRoots Magazine - September 2001