. The Canadian field-naturalist. Natural history. 1997 Cosens, Qamukaq, Parker, Dueck and Anardjuak: Bowhead Whales 383. 68°00 Figure 2. Aerial reconnaissance survey routes flown and Bowheads seen in August, 1994. and end of each transect. This observer also recorded Bowhead and other marine mammal sightings along with their GPS locations. The two observers in the rear of the aircraft recorded the time of day, species and group size of each sighting. The location of these sightings was determined by matching time of day with the GPS data recorded by the observer in the co-pilot's seat. All sig
. The Canadian field-naturalist. Natural history. 1997 Cosens, Qamukaq, Parker, Dueck and Anardjuak: Bowhead Whales 383. 68°00 Figure 2. Aerial reconnaissance survey routes flown and Bowheads seen in August, 1994. and end of each transect. This observer also recorded Bowhead and other marine mammal sightings along with their GPS locations. The two observers in the rear of the aircraft recorded the time of day, species and group size of each sighting. The location of these sightings was determined by matching time of day with the GPS data recorded by the observer in the co-pilot's seat. All sightings, including those of the pilot, were used to tabulate numbers seen. Inclusion of the sightings made by the pilot and the observer in the co-pilot's seat resulted in sampling of the strip under the plane because animals seen ahead of the aircraft were counted. Data were checked for dupli- cate sightings to ensure that Bowheads seen by more than one observer were counted only once in the analysis. Observers remained in the same seats throughout the survey. Using an inclinometer, the survey strip width was estimated to be 600 m on either side of the air- craft. Animals estimated to be within 600 m of the aircraft were counted. Identification of species and accurate estimation of group size was found to be difficult for whales more than about 600 m from the aircraft; however, sightability of whales with distance from the aircraft was not systematically documented. Inclinometer readings were periodi- cally taken during the survey to confirm that sight- ings were within 600 m. Data from the 13 August survey were not used because Beaufort 4-5 wind conditions reduced visi- bility of the whales. The number of Bowhead sight- ings made in this survey was about half that made in the other two and most of these sightings were made along the flight line of the plane thus the strip width appeared to be reduced from what it was on calm days. Using the method outlined by Kingsley (1993),
Size: 1803px × 1386px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectnaturalhistory, booky
