42. 
43. 
44, 
Effects of human use (boating and 
camping) are among the impacts acting 
upon natural riparian communities in 
Big Bend National Park, Texas. Site 
impacts have occurred as a result of 
recreational use, but not to the point 
where ecological conditions, as indi- 
cated by the rodent fauna and vegeta- 
tion, are in jeopardy. 
BOATING, CAMPING, DESERTS, RIVERS, REC- 
REATION MANAGEMENT, U.S. NATIONAL PARKS, 
RODENTS 
Bondello, M. C. 1976. The effects of 
high-intensity motorcycle sounds. on 
the acoustical sensitivity of the 
desert iguana, Dipsosaurus dorsalis. 
M.A. Thesis. California State Univer- 
sity, Fullerton. 38 pp. 
Acoustical sensitivity of desert igua- 
nas exposed to various levels” and 
durations of motorcycle sounds was 
tested. Permanent sensitivity losses 
occurred in some cases, at a dose of 
less than one hour. Damaging effects 
of motorcycle sounds on desert igua- 
nas, along with reported habitat de- 
struction by off-road vehicles, indi- 
cates a potential detrimental impact 
of recreational vehicles on desert 
wildlife. 
OFF-ROAD VEHICLES, DESERTS, DESERT IGUA- 
NA 
Booth, C. J. 1978. Breeding success of 
red-throated divers. Br. Birds 71:44, 
Human disturbance is discussed as a 
factor in nest losses of red-throated 
divers in Great Britain. Divers breed 
successfully in several areas where 
skuas and gulls are abundant, but 
where human disturbance has increased 
breeding success of divers has been 
reduced, presumably through human-in- 
duced nest’ predation. Disturbance 
causes adults to temporarily abandon 
eggs and young, leaving them vulner- 
able to predation. 
RESEARCH IMPACTS, DISTURBANCE (GENERAL), 
WILDLIFE VIEWING, LAKES, PREDATION, 
FLIGHT DISTANCE, RED-THROATED DIVER 
Bourget, A. A. 1970.  Interrelation- 
ships of eiders, herring gulls, and 
black-backed gulls nesting in mixed 
colonies in Penobscot Bay, Maine. 
45. 
46. 
47. 
M.S. Thesis. 
ono. 123 pp, 
University of Maine, Or- 
Effects of observer's presence on ei- 
ders and gulls during an ecological 
study were examined by comparing dis- 
turbed and undisturbed colonies. As a 
result of human disturbance the breed- 
ing cycles of eiders, black-backed 
gulls, and especially herring gulls 
were delayed by as much as one week, 
Hatching success of eiders appeared to 
be unaffected. 
RESEARCH IMPACTS, COASTAL ZONES, COMMON 
EIDER, GREAT BLACK-BACKED GULL, HERRING 
GULL 
Bowman, E. G. 1969. The grizzly bear 
in the National Parks. Am. For. 75 
(7):16-18, 56-58; 75(8):16-18, 52-55. 
This two-part nontechnical article ex- 
amines grizzly bear-human conflicts in 
U.S. National Parks. The biology and 
behavior of bears and aspects of visi- 
tor behavior that lead to conflicts 
with bears are discussed. Management 
recommendations are presented aimed at 
maintaining bear populations in parks 
while assuring an acceptable degree of 
human safety. 
CAMPING, HIKING, HORSEBACK RIDING, TOUR- 
ISM, WILDLIFE VIEWING, FORESTS, HUMAN 
HEALTH AND SAFETY, THREATENED AND ENDAN- 
GERED SPECIES, RECREATION MANAGEMENT, 
WILDLIFE |= MANAGEMENT , U.S. NATIONAL 
PARKS, GRIZZLY BEAR 
Brander, R. B. 1974. Ecological im- 
pacts of off-road recreation vehicles. 
Pages 29-35 in Outdoor recreation re- 
search: Applying the results. Papers 
from a workshop, 19-21 June 1973, Mar- 
quette, Mich. U.S. For. Serv. Gen. 
Tech. Rep. NC-9. 
Potential impacts of snowmobiles on 
wildlife are inferred from a review of 
literature concerning snowmobile im- 
pacts on ecosystems. Future research 
needs and management goals are dis- 
cussed. 
OFF-ROAD VEHICLES, FORESTS, RECREATION 
MANAGEMENT, REVIEW, WILDLIFE (GENERAL) 
Braun, C. E. 1971. Habitat require- 
ments of white-tailed  ptarmigan. 
Proc. Annu. Conf. West. Assoc. State 
Game Fish Comm. 51: 284-292. 
