the alpine population of rock ptarmigan and its sufficient protection, the analysis of
the monitoring results from the whole Alps would be necessary.
12.2 Climate-Change Related Problems
In order to predict the effects of climate change on the species population, knowledge
of the effect of climate on its life history is essential (Novoa et al. 2008). Climate and
weather characteristics are considered to be one of the most important factors
influencing the population dynamics of rock ptarmigan. Breeding success, juvenile
and adult survival heavily depends on weather conditions. Nesting success is negatively correlated with the amount of rainfall in particular during the hatching period
(Novoa et al. 2008). The proportion of chicks in August depends on the onset of snow
melt, mean minimal and maximal air temperatures during spring and early summer
(Novoa et al. 2008). In all the species distribution models, the mean July temperature,
annual precipitation, July water budget and July cloud cover were found to be the most
powerful bioclimate variables for determining the distribution patterns of rock ptarmigan (Revermann et al. 2012). Furthermore, the powerful influence of the mean July
temperature on rock ptarmigan distribution was stressed by Revermann et al. (2012) in
connection with the heat dissipation limit theory (Speakman and Kro ´l 2010). Following
this theory, we can explain the appearance of endothermic animals, including rock
ptarmigan, in areas with lower temperatures in an attempt to avoid hyperthermia.
The increasing temperatures and smaller amounts of precipitation in winter
months will result in a thinner snow layer. This means a lack of snow for deep
burrows for roosting and sheltering in harsh winter conditions (Bossert 1980;
Cramp and Simmons 1980; Hoffman and Braun 1977). Additionally, a decreased
snow layer results in a deficiency of certain available food (Bossert 1980).
Events related to global warming, such as a higher frequency of extreme weather
conditions, may affect hatching success, chick survival (Webb 1987 cited in Wilson
and Martin 2008) and energy expenditure for food provisioning and thermoregulation of nesting females (Wiebe and Martin 1997 cited in Wilson and Martin 2008).
12.3 Monitoring Objectives and Methods
for Rock Ptarmigan Population
Counting of calling males is based on the fact, that displaying proceeds inside
territories or on borders and that territory borders may remain unchanged for
decades. Territorial males can be heard for distances 1 km (Bossert 1977). The
most important monitoring goals in TNP are:
1. To determine the distribution and dynamics of rock ptarmigan populations by
direct observations, callings, and tracks, like feathers, droppings, footprints etc.
(monitoring and dispersed observations): all year.
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T. Petras
the monitoring results from the whole Alps would be necessary.
12.2 Climate-Change Related Problems
In order to predict the effects of climate change on the species population, knowledge
of the effect of climate on its life history is essential (Novoa et al. 2008). Climate and
weather characteristics are considered to be one of the most important factors
influencing the population dynamics of rock ptarmigan. Breeding success, juvenile
and adult survival heavily depends on weather conditions. Nesting success is negatively correlated with the amount of rainfall in particular during the hatching period
(Novoa et al. 2008). The proportion of chicks in August depends on the onset of snow
melt, mean minimal and maximal air temperatures during spring and early summer
(Novoa et al. 2008). In all the species distribution models, the mean July temperature,
annual precipitation, July water budget and July cloud cover were found to be the most
powerful bioclimate variables for determining the distribution patterns of rock ptarmigan (Revermann et al. 2012). Furthermore, the powerful influence of the mean July
temperature on rock ptarmigan distribution was stressed by Revermann et al. (2012) in
connection with the heat dissipation limit theory (Speakman and Kro ´l 2010). Following
this theory, we can explain the appearance of endothermic animals, including rock
ptarmigan, in areas with lower temperatures in an attempt to avoid hyperthermia.
The increasing temperatures and smaller amounts of precipitation in winter
months will result in a thinner snow layer. This means a lack of snow for deep
burrows for roosting and sheltering in harsh winter conditions (Bossert 1980;
Cramp and Simmons 1980; Hoffman and Braun 1977). Additionally, a decreased
snow layer results in a deficiency of certain available food (Bossert 1980).
Events related to global warming, such as a higher frequency of extreme weather
conditions, may affect hatching success, chick survival (Webb 1987 cited in Wilson
and Martin 2008) and energy expenditure for food provisioning and thermoregulation of nesting females (Wiebe and Martin 1997 cited in Wilson and Martin 2008).
12.3 Monitoring Objectives and Methods
for Rock Ptarmigan Population
Counting of calling males is based on the fact, that displaying proceeds inside
territories or on borders and that territory borders may remain unchanged for
decades. Territorial males can be heard for distances 1 km (Bossert 1977). The
most important monitoring goals in TNP are:
1. To determine the distribution and dynamics of rock ptarmigan populations by
direct observations, callings, and tracks, like feathers, droppings, footprints etc.
(monitoring and dispersed observations): all year.
188
T. Petras