R: Distance-sampling data for the Island Scrub Jay (_Aphelocoma...

issj {unmarked} | R Documentation

## Distance-sampling data for the Island Scrub Jay (Aphelocoma insularis)

### Description

Data were collected at 307 survey locations ("point transects") on Santa Cruz Island, California during the Fall of 2008. The distance data are binned into 3 distance intervals [0-100], (100-200], and (200-300]. The coordinates of the survey locations as well as 3 habitat covariates are also included.

### Usage

    data(issj)

### Format

A data frame with 307 observations on the following 8 variables.

`issj[0-100]`

  Number of individuals detected within 100m

`issj(100-200]`

  Detections in the interval (100-200m]

`issj(200-300]`

  Detections in the interval (200-300m]

`x`

  Easting (meters)

`y`

  Northing (meters)

`elevation`

  Elevation in meters

`forest`

  Forest cover

`chaparral`

  Chaparral cover

### References

Sillett, S. and Chandler, R.B. and Royle, J.A. and Kery, M. and Morrison, S.A. In Press. Hierarchical distance sampling models to estimate population size and habitat-specific abundance of an island endemic. Ecological Applications

### See Also

Island-wide covariates are also available `cruz`

### Examples

    data(issj)
    str(issj)
    head(issj)

    umf <- unmarkedFrameDS(y=as.matrix(issj[,1:3]), siteCovs=issj[,6:8],
        dist.breaks=c(0,100,200,300), unitsIn="m", survey="point")
    summary(umf)

[Package unmarked version 1.0.0 Index]