Species under study
The study
involves two native deer of South America, both distributed in the
extreme South of Andes Mountains and declared as Vulnerable (UICN,
2008). The Huemul (Hippocamelus bisulcus) is a medium deer
size that has a home range between 40 to 300 hectares (Gill, et al.,
2008; Aldridge &. Montecinos, 1999). The Pudu (Pudu pudu)
it is the smallest deer in the world, with a weight of 10 to 12 kg.
This deer has a home range between 16 to 47 kg. Home range size
was considered the first predictor variable related to animal
displacement.
Experimental design
Five (5) regions were
selected for each species with natural species habitat. The regions
contain places without disturbances and places with anthropogenic
disturbances as rows and housing. These places were considered as the
second predictor variable therefore three sampling units were
establishing in each region: control, linear and spot. The area
measures of the samples were defined using species home range
(Tab.1). The regions are considered replicates of the sample.
The
number of individuals was observed and recorded using a transect
method. Inside sample 10 transect were defined (details of transect are
in Tab.1). The measures were obtained during the December to
January, and all samples inside of a region were taking at the same
time. The experimental design is summarized in Figure 1.
Figure 1: DIAGRAM OF EXPERIMENTAL DESIGN
The
experiment is composed for two treatments Animal Movement and Landscape
Disturbance. Two categories of Animal Movement were considered for the
first predict variable; Large Home Range (Large HR) and Small Home
Range (Small HR). Three categories of Landscape Disturbance were
considered as the second predict variable; Control, Linear Disturbance
and Spot Disturbance. Number of individuals in sample was considered as
the response variable.
Table 1: Information used for determine the sample area and transect longitude
*1: Density represent the number of individual per sample area expect to find considering a average home range of 250 ha. for Huemul and 20 ha. for Pudu. *2: Total transect designed for asses the 5% of sample area. *3: Transect area were estimated considering a 10 transect for sample; Transect area = [Total transect area / 10], *4: Visibility Is the maximum distance of animal observation from transects. *5: Transect longitude: Transect longitude = Transect area / (visibility*2).