Dealing with Trade-Offs in Destructive Sampling Designs for Occupancy Surveys
Fig 3
Optimal search strategies for Hemiergis millewae.
The plot depicts the minimum number of Triodia hummocks that must be searched at each site to reach a cumulative probability of detection of H. millewae of 0.95, dependent on the minimum volume of each hummock searched and the weight (importance) given to either minimising replication or the quality of hummocks searched. The x-axis displays the weight on minimising the number of hummocks sampled (wn). The weight on minimising the volume of each hummock searched is 1 minus wn. Hence, a value of 0.5 on the x-axis corresponds to placing equal weight on minimising the number of hummocks sampled and minimising their quality. The text to the right of each combination shows the minimum volume of the hummocks to be searched to achieve the threshold cumulative probability of detection of 0.95. Panel (a) indicates the optimal strategies based on the detection model derived from sites with known occupancy only; panel (b) describes the optimal strategies based on the detection model derived from the full set of surveyed sites.