Precision of density estimates

Author

Centre for Research into Ecological and Environmental Modelling
University of St Andrews

Modified

November 2024

Precision of density estimates

This exercise examines the ability to precisely estimate density from line transect data.

The data are again simulated and there are two data sets. The first data set you will analyse has transects of varying lengths; increasing from west to east in the study area. In addition to this change in transect lengths, there is an accompanying gradient in animal density, decreasing from west to east. In combination, this leads to transects with very high encounter rates in the west and transects with very low encounter rates in the east.

You are to analyse these data in several ways, focusing your attention on the precision associated with each estimation method.

There is a second data set that shares the same survey design (short transects in the west, long transects in the east). But in this second data set, there in no accompanying animal density gradient. Perform similar analyses with this data set.

Lecture materials

Lecture discussion

Exercise materials

Supplemental materials

Could use left-truncation

There is no supplemental material

References