gremAbundance: Calculate abudance using the gREM.

In timcdlucas/encounteR: Estimate animal density and abundance using random encounter models

Description

Calculate abundance from count data using the gREM.

Usage

gremAbundance(z, alpha, theta, r, animalSpeed, t, area)

Arguments

z	Number of detections.
alpha	Call width in radians.
theta	Detector width in radians.
r	Sensor detection radius in metres.
animalSpeed	Average animal speed in metres per second.
t	Total survey time. This is the amount of time the sensors are active multiplied by the number of sensors used.
area	The size of the study area in metres squared.

Details

It is necessary to define a study area to calculate abundance rather than density. The easiest way to do this is to define the study area before data collection and then place camera traps/acoustic detectors/etc. randomly inside the area. It is more difficult to define the area studied post hoc.

Note that the REM of Rowcliffe et al. 2008 can be used by setting alpha to zero and the Gas Model of Yapp 1956 can be used setting alpha and theta to zero.

References

Lucas, T. C. D., Moorcroft, E. A., Freeman, R., Rowcliffe, J. M., Jones, K. E. (2015), A generalised random encounter model for estimating animal density with remote sensor data. Methods in Ecology and Evolution. doi: 10.1111/2041-210X.12346

Rowcliffe, J., Field, J., Turvey, S. & Carbone, C. (2008) Estimating animal density using camera traps without the need for individual recognition. Journal of Applied Ecology, 45, 1228-1236.

Yapp, W. (1956) The theory of line transects. Bird Study, 3, 93-104.

See Also

gremDensity

timcdlucas/encounteR documentation built on May 31, 2019, 1:48 p.m.