Mountain Wildlife - Mountain Geography: Physical and Human Dimensions - page 397

CHAPTER EIGHT
Mountain Wildlife
LARRY W. PRICE and VALERIUS GEIST
The study of mountain animals is somewhat more difficult than the study of vegetation.
Animals are mobile and may be hard to follow because of broken topography, dangerous
weather, or sheer inaccessibility due to distance, terrain, and logistical prob-
lems—national bureaucracies included. The firmly rooted plants can be more easily stud-
ied and their distribution mapped. This is possible with animals only through year-round
observations, often under trying circumstances. Animal distribution is complicated by
daily or seasonal migrations. Moreover, their seasonal home ranges, breeding areas, and
migration routes may be widely dispersed. Some are full-time residents; others are part-
time residents, temporary visitors, or even unintentional migrants, such as the occasional
swarms of lowland insects drawn up to high altitudes and deposited on snow-fields by as-
cending air currents. Since the 1970s, the study of radio-tagged individuals has made the
biology of many species much more accessible. Moreover, mountain terrain also offers
advantages: Large animals on steep slopes, unobstructed by tall vegetation, can often
be observed continuously or followed visually for extended periods of time. However, the
difficulties of logistics remain, as do the dangers of working in all seasons in mountains.
Some classic studies of animals in the mountains that illustrate these advantages and
difficulties include Murie (1944) on Alaskan wolves and Dall's sheep; Welles and Welles
(1961), Geist (1971, 2002), and Schaller (1975, 1998) on mountain ungulates; and Barash
(1989) on marmots.
Altitude and latitude are often parallel: Most animals at high altitudes or latitudes
are really summer residents that spend most of the year at lower altitudes or latitudes.
These include many of the larger and more mobile species. Birds are the most mobile,
of course, and some species, such as eagles and hawks, commute daily to the alpine tun-
dra. They frequently nest in the subalpine or montane zone, riding the slope breezes
and updrafts up the mountain to spend their summer days foraging for prey above the
timberline. On the other hand, the species that live permanently, or at least reproduce,
in high mountains are of greatest significance for our purposes, since they reveal most
clearly the characteristics and adaptations necessary to survive in the mountain milieu.
Seasonal latitudinal and altitudinal migrants take advantage of the summer's productiv-
ity at high elevations in order to reproduce, using lower elevations and latitudes mainly
to overwinter.
In spite of the multifaceted nature of animal populations, they share many character-
istics with mountain vegetation, as discussed in Chapter 7. One of these is the decrease
in number of species with altitude, with the exception of some desert mountains that