152. 
153. 
status of ospreys in northwestern Cal- 
ifornia. Pages 223-240 in J. C. Og- 
den, ed. Transactions of the North 
American Osprey Research Conference, 
10-12 February 1972, Williamsburg, Va. 
U.S. Natl. Park Serv. Trans. Proc. 
Ser. 2. 
Data are presented concerning abun- 
dance and reproduction of ospreys in 
California. Factors influencing 
fledgling productivity are discussed, 
including human disturbance. Logging 
and shooting were found to seriously 
affect nesting ospreys, but there was 
no indication that recreational activ- 
ities including sightseeing, camping, 
fishing, and swimming were detrimental 
to breeding success of ospreys. 
CAMPING, FISHING, SWIMMING, TOURISM, HA- 
RASSMENT, FORESTS, RIVERS, OSPREY 
Fyfe, R. 1969. The peregrine falcon in 
northern Canada. Pages 101-114 in J. 
J. Hickey, ed. Peregrine falcon popu- 
lations: Their biology and decline. 
University of Wisconsin Press, Madi- 
son. 
Recent evidence suggests that the 
peregrine remains a common breeding 
bird in northern Canada, although a 
local decline in one area was attrib- 
uted to human disturbance. Human in- 
terference with peregrines near north- 
ern settlements is a possible decimat- 
ing factor. 
DISTURBANCE (GENERAL), FORESTS, TUNDRA, 
THREATENED AND ENDANGERED SPECIES, PERE- 
GRINE FALCON 
Fyfe, R. W., and R. R. Olendorff. 1976. 
Minimizing the dangers of nesting 
studies to raptors and other sensitive 
species. Can. Wildl. Serv. Occ. Pap. 
23. I1/ pp. 
Problems resulting from human inter- 
ference with the nests of sensitive 
bird species, principally raptors, are 
discussed. These include desertion of 
nests by frightened adults with conse- 
quent threats to young, and problems 
related to mishandling and photograph- 
ing young in nests. Possible solu- 
tions to problems are outlined. 
RESEARCH IMPACTS, WILDLIFE VIEWING, PRE- 
DATION, THREATENED AND ENDANGERED SPE- 
CIES, RAPTORS 
154. Gantzel, D. H. 1978. Great crested 
grebes breeding on rivers. Br. Birds 
71: 226-227. 
The author compares 2 reports in the 
literature concerning river-breeding 
grebes in Great Britain: One from 
1932 stating that boats greatly dis- 
turbed grebes, and another from 1977 
which observes that grebes are remark- 
ably tolerant of boats passing within 
a few meters. The author concludes 
that grebes seem to tolerate boats in 
narrow rivers where disturbance is un- 
avoidable. 
BOATING, RIVERS, LAKES, FLIGHT DISTANCE, 
GREAT CRESTED GREBE 
155. Garber, D. P. 1972. Osprey nesting 
ecology in Lassen and Plumas Counties, 
California. M.S. Thesis. Humboldt 
State University, Arcata, Calif. 59 
pp: 
Nesting efforts of ospreys were stud- 
jed in northeastern California. Major 
cases of nesting failure were high 
winds and eggshell breakage, but human 
disturbance was responsible for 334% of 
observed egg losses. In one case 
campers caused adult ospreys to aban- 
don a nest with eggs. During fledg- 
ling counts young ospreys sometimes 
flew from nests, apparently for the 
first time. Such early flights may 
increase the incidence of injury and 
predation of fledglings. 
CAMPING, RESEARCH IMPACTS, DISTURBANCE 
(GENERAL), FORESTS, LAKES, RIVERS, WILD- 
LIFE MANAGEMENT, U.S. NATIONAL FORESTS, 
U.S. NATIONAL PARKS, OSPREY 
156. Garber, D. P. 1972. Special wildlife 
investigations: Osprey study, Lassen 
and Plumas Counties, California. Cal- 
if. Dept. Fish Game Project W-054-R- 
03/WP03/J10. 38 pp. (MIN 047280122). 
Human disturbance caused 36% of osprey 
egg and nestling losses at 15 nests 
studied in California. Campers parked 
near a nest caused ospreys to abandon 
the nest and eggs. There is evidence 
that gull predation on eggs occurred 
in the absence of adult’ ospreys. 
DISTURBANCE (GENERAL), CAMPING, PREDA- 
TION, FORESTS, OSPREY, GULLS 
157. Garton, E. 0., C. W. Bowen, and T. C. 
Foin. 1977. The impact of visitors 
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