1. Choosing a Route
The routes will be 14.4 km long, consisting of 10 stops situated 1.6 km apart. Stops can be slightly farther apart if the 1.6 km distance puts
one at an inconvenient or dangerous spot. The number of stops was chosen
to maximize the number of routes run, an important factor in obtaining
statistically significant results for population trend monitoring. The distance between the stops was a compromise between being
sure of not counting the same owl twice and keeping the overall distance
travelled to a minimum. The 1.6 km distance may seem awkward, but it makes the protocol comparable
to present Breeding Bird Survey (BBS) methods and will allow the
protocol to be used easily in the US. Although this is a “made-in-Canada” protocol, it is likely
that it will be adopted throughout North America as the standard way to
monitor owl populations.
In most cases, routes will be initially chosen by the observer. Unlike BBS rules, we do not require that routes be chosen
randomly, since we realize that across most of the province there are
few routes in each area that meet the following criteria. Roads should be accessible in winter and should not be active
log hauling routes or busy highways for reasons of surveyor safety and
improved detectability of owls. Choose secondary roads that have little traffic and sufficient safe points for
stopping. The roads should be permanent to allow for long term use and should go through a variety
of habitat types.
Entire routes or parts of the route can also be surveyed by snowmobile, horse,
skis, or snowshoes along cutlines or trails. However, we do not recommend doing the complete route on foot, as
it is a considerable distance to go at night.
Please notify the BC Program Manager when you have chosen a new route to ensure
that your route does not overlap any other routes.
2. Route Descriptions
Observers setting up a new route should clearly mark it on a topographical map, preferably one of
1:50,000 scale, and submit the map with their survey results. The ten individual stops should also be clearly marked on the
map, and a detailed description of their location written on the back of
the map or on a separate sheet. The positions of these stops will be digitized so that the information can
be used in GIS-based studies. If observers have access to hand-held GPS units, the exact coordinates of
each stop should be taken, and reported in UTM (NAD 83) units.
3. Time of Night
Owl call rates tend to be lowest in the middle of the night (midnight to 04:00).Surveys should be therefore conducted between a half hour after
sunset and midnight; try to conduct the survey at the same time of
night every subsequent year.
4. Time of Year
Surveys should be done in March in southern BC (Vancouver Island, south coast,
Lower Mainland, Thompson-Okanagan and Kootenays); mid-March to mid-April
in central BC (Cariboo-Chilcotin, Bulkley Valley, Prince George, QCI,
etc.) and in April in northern BC (Peace River, Fort Nelson, Atlin,
etc.) (see map). Try to do surveys in subsequent years at about the same time (i.e. if you do your
survey this year on March 10, try to do it next year within a week or so
of that date). If you have time to do more than one route, please do! Since Flammulated Owls will obviously not be covered by this
protocol, you could do special Flammulated Owl routes in June if you
live in the southern Interior.
5. Environmental Conditions
Environmental conditions such as wind, rain, snow and temperature can directly affect
owl call counts. Surveys should not be conducted in the following conditions: wind speed over a
Beaufort Scale of 3 (see below), during precipitation events (although
if a light snow or rain begins during the survey it can still be
completed), or when the temperature is below –10oC (14oF). This will also reduce the risks involved with conducting the
surveys.
| Beaufort No. |
Wind Speed km/hr. |
Indicators of Wind Speed |
| 0 |
Less than 2 |
Smoke rises vertically |
| 1 |
2 to 5 |
Wind direction shown by smoke drift |
| 2 |
6 to 12 |
Wind felt on face, leaves rustle |
| 3 |
13 to 19 |
Leaves, small twigs in constant
motion |
| 4 |
20 to 29 |
Raises dust/loose paper, small
branches move |
| 5 |
30 to 38 |
Small trees in leaf sway |
