DetectionExpe: Detectability of Leks during Grid Cells Search

In ClementCalenge/caperpyogm: Estimation of the Number of Male Capercaillie in the Pyrenees Mountains

Description

This dataset contains the result of an experiment carried out to assess the detectability of leks during grid cell search.

Usage

data("DetectionExpe")

Format

A data frame with 16 observations on the following 4 variables.

observer

a character vector containing the type of observer that searched the grid cell (experienced/inexperienced).

Nquad

a numeric vectors indicating the number of leks in the grid cell searched by the observer.

Nsect

a numeric vector indicating how many leks were actually included in the sector defined by the observer, among those present within the grid cell.

Ndete

a numeric vector indicating how many leks were detected by the observers among those both present in the grid cell and included in the search sector.

Details

Our model requires to model the probability to detect an unknown lek during grid cell search. Such searches are carried out in two steps: (i) a search sector is defined by the observer within a grid cell, so that their subjective assessment of the probability to include a lek is maximal, (ii) the observer will then search unknown leks within the sector during one morning. Because of the subjective definition of the sector and the variability in detection probability, we carried out an experiment to model the detection process during the model.

We carried out an experiment with two observers to fit such a model. Two observers, one highly experience and a new observer with no experienced were told to search for new leks in grid cells unknown to them, but known to us (some of them containing no leks). We recorded the sector delimited by the observer, as well as the leks detected by the observers.

Source

Observatoire des Galliformes de Montagne. 90 impasse des daudes 74320 Sevrier, France.

References

Calenge C., Menoni E., Milhau B., Foulche K, Chiffard J., Marchandeau S. (in prep.). The participatory monitoring of the capercaillie in the French Pyrenees.

Examples

## The data frame
DetectionExpe

## Total number of leks in grid cells
Nq <- tapply(DetectionExpe$Nquad, DetectionExpe$observer, sum)

## Total number of leks in delimited Sectors
Ns <- tapply(DetectionExpe$Nsect, DetectionExpe$observer, sum)

## Total number of detections
Nd <- tapply(DetectionExpe$Ndete, DetectionExpe$observer, sum)

## Proportion
data.frame(Nq,Ns,Nd)

ClementCalenge/caperpyogm documentation built on Sept. 14, 2021, 4:14 p.m.