Manitoba's Nocturnal Owl Survey:
2001 Progress Report

Prepared by Heidi E. den Haan

Our Purpose and the Value of Your Participation

Birds of prey, including the mysterious and majestic owls, are high on the food chain and as such are vulnerable to environmental change brought on by our modern activities. These changes can include toxins in their food supply, absence of food and the absence of nesting and hunting grounds, otherwise known as habitat loss. This survey seeks to provide sound information on owl distribution, habitat use, abundance and population trends. This will lay the groundwork for the development of sound conservation strategies by identifying species in need and by providing a tool for evaluating current management programs. An equally important survey goal is to provide an opportunity for people such as yourselves to get involved through active participation. We could not do all this without you!

Where We Surveyed in 2001

In 2001, 57 routes were surveyed (slightly less than the year before) and are displayed on the map shown to the right. Routes at Spruce Siding (near Richer), Fire Road 31 South (near Hadashville), Glenboro-Stockton and Athapap Road (near Cranberry Portage) have all been done 2 or more times in 2001.

The map is divided into regions known as 'Bird Conservation Regions' (BCR), accepted widely in North America as the planning unit for bird conservation studies. (Click map for larger version.)

The survey is getting better with increasing representation in the western part of the province. To get accurate representation of owl populations throughout Manitoba we need more volunteers in the north and west! If you can help out, let us know! Every little bit helps!

Charts

As most of you know, the survey protocol changed significantly in the year 2000. Route length, spacing between listening stations and listening time all changed and as well, the playback was dropped. The change was made in order to standardize the methods across Canada and become part of a nation-wide owl survey. As such, the owl detection trends from the two sampling periods are separated in Graphs 1 & 2.

These charts show the number of each owl species heard per kilometer surveyed during the 11-year survey period. (Click graphs for larger versions.)

Interesting Factoids 2001...

* In 2001, 57 routes were surveyed by 91 volunteers, down slightly from 59 Routes in 2000. For every station surveyed, 0.27 owls were heard which was up slightly up from 2000 when 0.24 were heard for every station surveyed. This means that surveyors have a greater than 25% chance of hearing an owl at a station. (Click pie chart for larger version.)

* For every 1 km surveyed, 0.17 owls were heard, up from 2000 when 0.15 were heard for every 1 km surveyed. That equals one owl for every 5.88 km traveled during the survey.

* Boreal Owls were the most commonly encountered (54 on 14 routes) followed by Great-Horned Owls (47 on 17 routes) and Northern Saw-whet Owls (29 on 15 routes). At least one owl was reported from 39 of the 57 routes surveyed.

* Rudolf Koes and Reto Zach struck gold on Route 4 (Bird River - PR 315) near Nopiming National Park with 13 owls heard (all Boreal Owls).

* Donna Danyluk, Ian Ward, Francois and Dana Blouin were fortunate as well surveying routes 1 (Powerview North) and 35 (314 - Nopiming - Cat Lake) which were not far behind each recording 10 owls.

* Four Boreal Owls, five Northern Saw-whet Owls and one Northern Hawk Owl were recorded at Powerview despite problems with traffic (thank you Donna and Ian for your perseverance and patience), and 10 Boreal Owls were recorded at Cat Lake.

* Route 131 (Vogar West), surveyed by Georgina and Raymond Larson, was close behind with nine owls reported (seven Great Horned Owls and two Great Grey Owls).

The New Survey Protocol

In the year 2000 the protocol for Manitoba's Nocturnal Owl Survey was changed dramatically in order to be part of the international standard for monitoring owls in North America. By using one common protocol across Canada and the U.S., we will be better able to monitor owl population trends across broad geographic areas, similar to that done by the Breeding Bird Survey.

Briefly, the major changes for 2000 were:

* 2 minute silent listening period per station with no tape playback

* 1.6 km spacing between stations

* routes in multiples of 10 stations each

* random route locations

FAQs

Question: Can I create my own route?: Answer: As tempting as it is to survey in an area where owls are known to be abundant, if everyone did this than we would not get an accurate picture of the distribution and abundance of the different species of owls in our province. Because this is a scientific study and because we are attempting to create a standard protocol across Canada one rule we must conform to is that the routes be randomly distributed. The good news is there is some leeway in that you are given a choice between three possible routes to survey. I suspect that some of you may hear no owls at all. Although your disappointment is understandable, remember that even this data is valuable to the understanding of the owls' ecology. So take heart! And keep up the good work.
Question: Why are the listening stations spaced at 1.6 km (1 mile)?: Answer: We are adopting a standard spacing of 1.6 kms in Canada for two main reasons; 1) this distance reduces double counting of owls, and hence makes more efficient use of your time; and 2) if we were to use a playback at some point to target a certain species, spacing of 1.6 km reduces the influence of the playback on the next stop.
Question: Can I reduce the space between stations to fit more stations in a route?: Answer: We strongly recommend the minimum spacing of 1.6 km be maintained. If noise is a problem at a particular station, it can be moved slightly (100 m). However, so as not to alter the distance of the full route, measure your subsequent station 1.6 km from where this station was originally to be. The important feature is that the locations remain consistent from year to year, allowing for significant long term monitoring.
Question: Is it essential that my route have 10 stops?: Answer: Yes! Your route should have a minimum of 10 stops. The 10 stop route forms the basis for population monitoring and is an essential part of the study allowing for cross analysis of the data collected between routes. If you so choose, you can double your route to 20 stops, adding to the pool of data and doubling your fun!
Question: Why are there so many information sheets to fill out?: Answer: There has been a significant increase in the amount of forms to fill out. We are entering all this information into our database to make things easier in the future. Once you have filled out the surveyor information (name, address, etc.) you will not have to do so again, the same is true for the survey route information. The route description and map are essential should you stop doing the survey and your route is passed on to someone new.

Manitoba Owls Species Profile:

Northern Hawk Owl (Surnia ulula)

By Jim and Patsy Duncan

0ne of the least-studied birds of North America, the Northern Hawk Owl has a bold nature and seems to lack fear of humans, delighting birders, who often travel great distances to observe it. It is atypical in morphology and behavior compared to other northern hemisphere owls, resembling in many ways the accipiter hawks - hence the name Hawk Owl. Primarily diurnal, this species usually perches atop prominent trees. When flying, it either glides low over the ground at high speed or flaps its pointed wings in deep, powerful, falcon-like strokes. (Picture at right: Patsy Duncan holding a recently banded Northern Hawk Owl near South Junction Manitoba.)

Northern Hawk Owl, courtesy Anne Cook The only species in its genus, the Northern Hawk Owl breeds in the circumpolar boreal forest zone from Alaska eastward through Newfoundland, and from Scandinavia through Siberia. It nests in dead tree stubs or woodpecker holes, especially in open coniferous or mixed coniferous, deciduous forests, burned over areas, or muskeg. Although this owl winters throughout its breeding range, it periodically "invades" southern Canada and the northern United States. The magnitude and extent of these winter irruptions are thought to correlate with high reproductive success followed by severe winter conditions and decreased prey availability. Early studies suggest that this owl eats primarily small rodents, but recent evidence indicates that grouse, ptarmigan, and hares comprise a greater proportion of their diet than previously thought.

All North American owls, except the Burrowing Owl (Speotyto cunicularia), show appreciable reversed sexual size dimorphism - the female is larger than the male. However, this dimorphism is not strongly pronounced in the Northern Hawk Owl. Despite its lack of skeletal ear asymmetry, it can locate and capture concealed prey up to 30 cm under snow cover. While much remains to be learned of the natural history of this species on its breeding range, there is no evidence that this species is at risk.

Northern Hawk Owl and Boreal Owl (above) images, courtesy Anne Cook. For more great owl images visit: Digital Bird Photographs

More Bird Related Volunteer Opportunities in Manitoba

Breeding Bird Survey (BBS)	Migration Monitoring - Songbird Banding
Migration Monitoring - Hawk Watch	Christmas Bird Count (CBC)
Manitoba Conservation Data Centre	Prairie Nest Record Scheme
Project Feederwatch	Ferruginous Hawk Recovery Program
Bluebird Nest box Monitoring	Parkland Mews Falconry and Bird of Prey Education Centre
Manitoba Wildlife Rehabilitation Centre	Eastern Loggerhead Shrikes (Also in Nature North)
For more information on getting involved go to: http://www.gov.mb.ca/natres/managing/pif_volunteers.html

Delta Marsh Birding Festival

May 10-12, 2002. The Delta Marsh Birding Festival is a 3-day event for birders and bird lovers alike celebrating the diversity and wonder of birds! Delta has unique and wonderful birding opportunities with experts in all aspects of birding life. We hope you can join us for this celebration of bird life during the peak of spring migration at Delta:
* shorebird and waterfowl identification	* guided bird tours to various habitats
* birding by ear	* birding by canoe
* visits to Sharptail Grouse dancing grounds	* banquet with keynote speaker Jim Duncan
* fish fry and silent auction	* bird banding
* Mother's Day picnic	For more information call Russ Mead at 857-8637 or fax at 857-4683.
Delta Marsh Bird Observatory: www.dmbo.org

For information regarding conservation and wildlife in Manitoba see: www.gov.mb.ca/natres/wildlife/index.html

Northen Saw Whet Owl photo by ??
Northern Saw Whet Owl

Thanks To All Participants

Thank you to all participants of the 2001 Owl Survey veterans and new comers alike! We couldn't do this without you. Hats off to all those participants who surveyed more than one route. Your extra effort is greatly appreciated.

Owl Survey Participants in 2001

Cheryl Bailey, Jim Bell, Robert Berger, Francois and Dana Blouin, Mark Bodnar, James Bradley, Tim Byers, Dan Chranowski, Ward Christianson, Jack Crolly, Carolyn Curtis, Cal Cuthbert, Donna Danyluk, Buster Day, Jim, Patsy, Connor and Brooke Duncan, Jim Fisher, Foster Fournie, Maureen Frolick, Mike Gigian, Jeff Gowler, Harry Harris, Heather Hinam, George Holland, Wally Jansen, Louise Kernatz, Ken Kingdon, Rudolf Koes, Bill Koonz, Michaela Kraft, Georgina Larson, Raymond Larson, Patrice Letain, Matt Loewen, Kurt Mazur, Alex McIlraith, Celia McLaren, Don and Ardythe McMaster, Marilyn Meyer, Al Mickey, Lorelie Mitchell, Wayne Neily, Dayle Neufeld, Lory and Audrey Neufeld, Jeremiah Niekamp, Laura Pearson, Morley Pedwell, Charlotte Pedwell, Ray Pettinger, Barb Pettinger, Leon Pewarchuk, Aimee Pittet, Ryan Porteus, Bill Pruitt, David Raitt, Amelia Reid, Monica Reid-Wrong, Don and Roxie Reimer, Vic Reimer, Marlene Remple, Dave Roberts, Len Ryzner, Tom Scott, Rosalie Sigurdson, Connie Singleterry, Bob Smith, Isabelle Smith, Richard Staniforth, Diana Staniworth, Peter Taylor, Ross Teague, Lorna Teague, Lisa and Wes Tretiak, Will Trowell, Joanne Tuckwell, Jeff Turner, Lorraine Turner, Robyn and Todd Underwood, Piet Van Dijken, Liis Veelma, Marlene Waldron, Bill Walley, Ian Ward, Ted Wilson, Larry and Judy Winslow, Margaret Yorke, Reto Zach and all friends and family members we may have missed.

Thank you for your help with Manitoba's Nocturnal Owl Survey and we hope you are looking forward to the 2002 survey!