Skip to main content

Advertisement

Table 3 Sampling effort needed to monitor guanaco population trends in Santa Cruz province, southern Patagonia

From: Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported

   Monitoring program scenario
   50% in 5 years 50% in 10 years
   Increase Decrease Increase Decrease
   α = 0.2 α = 0.3 α = 0.2 α = 0.3 α = 0.2 α = 0.3 α = 0.2 α = 0.3
  Relative abundance 80 50 >120 90 40 20 80 60
All guanaco groups Low 110 80 >120 >120 80 40 120 80
Medium 70 50 120 80 30 20 80 50
High 40 30 70 50 20 20 40 30
Breeding groups Low >120 >120 >120 >120 >120 >120 >120 >120
Medium >120 >120 >120 >120 >120 >120 >120 >120
High 60 40 110 80 30 20 70 40
Non-breeding groups Low >120 >120 >120 >120 120 >120 80 >120
Medium >120 70 >120 >120 60 40 120 90
High 70 50 120 80 20 20 70 50
Solitary individuals Low >120 120 >120 >120 90 60 >120 120
Medium 60 40 120 80 30 20 60 50
High 50 30 90 60 30 20 50 40
Breeding groups   >120 >120 >120 >120 >120 >120 >120 >120
Non-breeding groups   >120 100 >120 >120 70 50 >120 90
Solitary individuals   90 60 >120 100 40 30 90 60
  1. Sampling effort is expressed as the number of randomly located 30-km survey transects needed to attain the desired power of 1-β = 0.80 for each hypothetical scenario. Separate estimates of sampling effort are also given for areas with different combinations of classes of guanaco relative abundance and type of guanaco group. Estimates are also given after pooling all classes of relative abundance.