Houston et al. • HOME RANGE SIZE OF BREEDING TURKEY VULTURES 
477 
Time Female 
30 Jun 1500 
1800 
2100 
i Jui ooo 
300 
600 
900 
1200 
1500 
1800 _ 
2100 KH 
ooo 
300 Bii 
600 
900 
1200 _ 
i5(ki Knp'i 
1800 
2100 
3 Jul 000 
300 ■■n 
6°o 
900 
1200 
1500 _ 
1800 KSS? 
2100 ■MS 
4 Jul 000 
3°o 
600 VI 
900 
FIG. 3. Attentiveness of female H 85754 while 
brooding downy young, 30 June^l July 2009. Black = 
present at nest site. 
export markets and increased slaughter and 
disposal of non-saleable older livestock at farm¬ 
steads (Dunn 2004). The average fed steer price in 
Saskatchewan in 2007-2008 fell below produc¬ 
tion costs to $84 per hundred-weight, only half the 
1942-1989 inflation-adjusted average price (Na¬ 
tional Farmers Union 2008). 
The lack of a substantial increase in the 
breeding home range size of Turkey Vultures 
near the northern limits of its range suggests food 
resources there are noi appreciably different from 
those farther south. It is also possible these limits 
are set by distances the birds travel twice annually 
to and from southern wintering areas (cf. Mandel 
et al. 2008. 2011). "Western North America 
populations of Turkey Vultures forego feeding en 
route, at least for most of their journey" 
(Bildstein 2006:191) and "the condition of adult 
migrants [in Venezuela| was below average in 
October and November following migration from 
the breeding grounds" (Kirk and Gosler 1994: 
933). Physiological and aerodynamic constraints 
on fat loading prior to migration may preclude 
longer seasonal movements. Studies of the size of 
breeding home ranges of Turkey Vultures, 
especially in the Neotropics of Central America, 
northern South America, and the temperate zone 
of southern South America, are warranted. 
ACKNOWLEDGMENTS 
We thank M. J. Mossman and an anonymous reviewer 
for helpful comments. Special appreciation is extended to 
Don Forbes and over a hundred Saskatchewan farmers for 
their co-operation and interest, and to Brent Terry and 
Michael Blom for the many days and miles involved in 
field work. PDM was supported by a grant from the Natural 
Sciences and Engineering Research Council (Canada). This 
manuscript is Hawk Mountain Contribution to Conservation 
Science. Number 198. 
LITERATURE CITED 
Ackerman. B. B.. F. A Leban, M. D. Samuel, and E. O. 
Garton. 1990. User’s manual for Program HOME 
RANGE. Second Edition. Technical Report 15. 
Forestry. Wildlife and Range Experiment Station. 
University of Idaho. Moscow. USA. 
Arrington. D. P. 2003. Flight characteristics of non¬ 
migrating populations of Turkey Vultures. Disserta¬ 
tion. Purdue University. West Lafayette. Indiana. 
USA. 
Bildstein, K. L. 2006. Migrating raptors of the world: their 
ecology and conservation. Cornell University Press, 
Ithaca, New York, USA. 
Brown, J. H. 1984. On the relationship between the 
abundance and distribution of species. American 
Naturalist 124:255-279. 
Brown, j. H. 1995. Macroecology. University of Chicago 
Press, Chicago. Illinois. USA. 
Chapman, F. M. 1933. The migration of turkey buzzards as 
observed on Barro Colorado Island, Canal Zone. Auk 
50:30-34. 
Coleman, J. S. 1985. Home range, habitat use, behavior, 
and morphology of the Gettysburg vultures. Thesis. 
Virginia Polytechnic Institute and State University, 
Blacksburg, USA 
Coleman. J. S. AND J. D. Fraser. 1989. Habitat use and 
home ranges of Black and Turkey vultures. Journal of 
Wildlife Management 53:782-792, 
DeVault. T. L.. B. D. Reinhart. I. L. Brisbin Jr., and 
O. E. Rhodes Jr. 2004. Home ranges of sympatric 
Black and Turkey vultures in South Carolina. Condor 
106:706-711. 
Dunn. F. 2004. Report of the Auditor General on the 
Alberta government's BSE-related assistance pro¬ 
grams. Auditor General of Albeita, Edmonton. Can¬ 
ada. www.oag.ab.ca 
Environmental Systems Research Insttute (ESR1) 
2005. ArcView CIS 3.2. Environmental Systems 
Research Institute Inc.. Redlands. California. USA. 
Fergcson-Lees, D. and D. a. Christie. 2001. Raptors of 
