gremAbundance: Calculate abudance using the gREM.
In timcdlucas/RandEM: Population density estimates via Random Encounter Models in R

Description Usage Arguments Details References See Also

View source: R/gREM.R

Calculate abundance from count data using the gREM.

1	gremAbundance(count, alpha, theta, r, v, tm, area)

`count`	Number of detections.
`alpha`	Call width in radians.
`theta`	Detector width in radians.
`r`	Sensor detection radius in metres.
`v`	Average animal speed in kilometers per day.
`tm`	Total survey time in hours. 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 kilometers squared.

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.

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.

gremDensity

timcdlucas/RandEM documentation built on May 29, 2019, 3:07 a.m.