Houston et al • HOME RANGE SIZE OF BREEDING TURKEY VULTURES 
475 
TABLE 3. Soaring flight characteristics for four Turkey Vultures occupying home ranges 
Canada. 2005-2007. 
in central Saskatchewan, 
Palagial lag 
transmitter # 
H0 
57953 
H2 
57952 
HS 
65544 
T2 
65545 
Totals 
% Total 
Total days 
61 
52 
61 
64 
238 
40 
Days <99 m elevation above nest house 
31 
21 
26 
17 
95 
Days >100 m elevation above nest house 
30 
31 
35 
47 
143 
60 
Hiahest flight (m) above nest house 
558 
902 
681 
627 
Date of highest flight 
10 Jul 
4 Aug 
6 Jul 
12 Jul 
Mean height of flights >100 m 
265 
405 
309 
304 
Mean height of all daily highest flights (m) 
152 
252 
197 
233 
Hours of highest flight (CST): 
1000 
1 
1 
2 
4 
3 
1100 
7 
4 
4 
3 
18 
12 
1200 
3 
5 
6 
3 
17 
12 
1300 
5 
3 
7 
8 
23 
16 
1400 
5 
5 
8 
10 
28 
19 
1500 
5 
1 
5 
11 
22 
15 
1600 
1 
6 
5 
5 
17 
12 
1700 
1 
4 
2 
5 
12 
8 
1800 
2 
1 
1 
4 
3 
1900 
1 
1 
1 
Totals 
30 
31 
37 
48 
145 
101 
Mean time (CST) of highest flight (hrs) 
1324 
1429 
1343 
1411 
al. 2008, 2011), which significantly reduces the 
cost of searching large areas for carrion. 
We found published records of only Ihrce 
vultures for which breeding home ranges were 
calculated. The two vultures tracked during the 
breeding season near Gettysburg had 95% MCP 
home ranges with a mean of either 69.4 km 2 
(Coleman and Fraser 1989) or 126.0 km 3 (Cole¬ 
man 1985). Arrington (2003) captured one adult 
female vulture on her nest at the Pigeon River 
Wildlife Area, northeastern Indiana; it had a 
100% MCP of 557 km 2 and a 90% kernel of 
9.9 km 2 based on 342 satellite transmitter 
readings. Our mean 95% MCP of 371 knr was 
similar. The size of our Saskatchewan home 
breeding ranges was uniquely limited to locations 
of known breeding vultures from incubation 
through fledging of young. Comparisons with 
other studies of the home-range size of non¬ 
breeding Turkey Vultures (e.g., Tenney 1986. and 
those studied by Coleman and Fraser 1989 and 
DeVault et al. 2004) are less appropriate. 
Tracking both members of a pair of Turkey 
Vultures (male it 85753 and female # 85754) 
during incubation and brooding provided new 
information. Both had relatively small and 
virtually identical home ranges. Each would 
incubate for either one or two consecutive nights 
when regular signals were received from both 
during 23-30 May (Fig. 2). However, brooding 
was exclusively by the female at night during 30 
June-4 July, bul with 6 hrs respite in mid-day 
(Fig. 3); signals were not received from the male 
during this time. Brooding by the female ceased 
after 27 hrs of continuous brooding on a notably 
cool and rainy day, 10 July (data from Environ¬ 
ment Canada, http://climate.weatheroffice.gc.ca). 
Identifying size of home ranges for Turkey 
Vultures near their northern range limits increases 
our understanding of how the species is adapting 
to recently occupied areas in Saskatchewan and 
elsewhere in Canada. We believe the recent 
human depopulation of rural areas, together with 
abandonment of farm buildings, has had a crucial 
role in increasing numbers of successfully nesting 
Turkey Vultures. Vulture nests were rarely 
discovered prior to the 1980s, and w ere restricted 
to difficult-to-find caves in badlands in extreme 
southern Saskatchewan and along major river 
valleys through southern and central Saskatch¬ 
ewan with occasional single-year use of cavities 
within large brush-piles. Northward range exten¬ 
sion is not involved, but in 1982-1984, the first 
four vulture pairs were found in deserted build¬ 
ings in centra I Saskatchewan and vultures were no 
longer relying on natural caves for nesting 
