AICcmodavg (version 2.0-3)

tortoise: Gopher Tortoise Distance Sampling Data

Description

This simulated data set is based on the biological parameters for the Gopher Tortoise (Gopherus polyphemus) reported by Smith et al. (2009). A half-normal distribution with a scale of 10 and without an adjustment factor was used to simulate the distance data for a study area of 120 km^2. An effort of 500 m in 300 line transects was deployed. A density of 72 individuals per km^2 was used in the simulation using the approach outlined in Buckland et al. (2001).

Usage

data(tortoise)

source

Buckland, S. T., Anderson, D. R., Burnham, K. P., Laake, J. L., Borchers, D. L., Thomas, L. (2001) Introduction to distance sampling: estimating abundance of biological populations. Oxford University Press: Oxford.

Smith, L. L., Linehan, J. M., Stober, J. M., Elliott, M. J., Jensen, J. B. (2009) An evaluation of distance sampling for large-scale gopher tortoise surveys in Georgia, USA. Applied Herpetology 6, 355--368.

Details

This data set is used to illustrate classic distance sampling (Buckland et al. 2001).

Examples

data(tortoise)
str(tortoise)

##plot distance data to determine if truncation is required
##(Buckland et al. 2001, pp. 15--17)
hist(tortoise$distance)