Applications - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 264

both at regional scale and at local scale. The differences at the local scale may
depend on local environmental conditions but also on the different human hunting
pressure.
Wildlife safaris are a relevant practice in touristic offering. Large animals attract
the curiosity of visitors, who often use aircraft facilities for a short survey, as is the
case of the Barren-ground caribou ( Rangifer tarandus ), a species that lives in great
herds in the extreme northern ranges. This species attracts tourists who generally
approach the largest herds by renting small airplanes. The observation from the air
creates several problems in this species, which depending on the height of the
airplane may show a panic response, strong escape response, stationary response, or
no visible response. Observations conducted to censuses the herds were collected
by Calef et al. ( 1976 ), who have investigated 736 groups of caribou. The variety of
reactions has been largely correlated with the height of the airplane. At an altitude
of 60 m the caribou had a panic reaction, with animals out of control, stumbling and
colliding with one another and crossing obstacles such as willow patches and trees.
When the airplane flight is at an altitude of 150 m during spring and fall, and 300 m
at other periods, this is sufficient to prevent the reactions of the caribou. The noise
produced by the airplane probably is the major cause of the panic reaction. This
study is important to set the height at which tourists may watch caribou without
negative consequences.
Also, actions motivated by the noble goal of feeding “wild pets” may represent a
serious threat affecting communication mechanisms. For instance, supplementing
birds can produce a negative effect on their song repertoire. In fact, Zanette
et al. ( 2009 ) have demonstrated as young song sparrow ( Melospiza melodia ) fed
by food-supplemented parents sang a less diverse song than young fed by non-food-
supplemented adults, because fed parents can produce more offspring, but with
poorer quality, increasing the risk of local population decline. This evidence
indicates that the manipulation of populations for “conservation” purposes in
some cases could produce negative effects on the future generations.

10.3 Acoustic Monitoring

Monitoring means to evaluate changes over time using a repeated standardized
sampling procedure. Monitoring is particularly required to track the dramatic
changes that modern human societies are producing at the planetary scale. In
particular, ecosystem dynamics represent the focus of most monitoring programs,
where cycling of water, cycling of nutrients, energy transfer, and species
relationships are the four main processes to be considered. Despite the relative
simplicity of using automated remote procedures and instruments to capture the
parameter described in the first three processes, the last requires a more sophisti-
cated approach.
Nature under energy constraints is rich with sounds and each sound can explain
in detail the magnitude, occurrence, and dynamics of a single process.