Rdistance (version 4.0.5)

sparrowDf: Brewer's Sparrow detection data frame in Rdistance >4.0.0 format.

Description

Detection data from line transect surveys for Brewer's sparrow on 72 transects located on a 4105 km^2 study area in central Wyoming collected by Dr. Jason Carlisle as part of his graduate work in the Wyoming Cooperative Fish & Wildlife Research Unit in 2012. Each transect was 500 meters long.

Format

A rowwise tibble containing 72 rows and 9 columns, one of which is nested data frame of detections. Each row represents one transect. The embedded data frame in column detections contains the detections made on the transect represented on that row.

Column descriptions:

1. siteID: Factor (72 levels), the transect identifier for that row of the data frame.

2. length: The length, in meters [m], of each transect.

3. observer: Identity of the observer who surveyed the transect.

4. bare: The mean bare ground cover (%) within 100 [m] of the transect.

5. herb: The mean herbaceous cover (%) within 100 [m] of the transect.

6. shrub: The mean shrub cover (%) within 100 [m] of the transect.

7. height: The mean shrub height [cm] within 100 [m] of the transect.

8. shrubclass: Shrub class factor. Either "Low"" when shrub cover is < 10%, or "High" if cover >= 10%.

The embedded data frame in column detections contains the following variables:

1. groupsize: The number of individuals in the detected group.

2. sightdist: Distance [m] from observer to the detected group.

3. sightangle: Angle [degrees] from the transect line to the detected group. Not bearing. Range 0 [degrees] to 90 [degrees].

4. dist: Perpendicular, off-transect distance [m], from the transect to the detected group. This is the distance used in analysis. Calculated using perpDists.

References

Carlisle, J.D. 2017. The effect of sage-grouse conservation on wildlife species of concern: implications for the umbrella species concept. Dissertation. University of Wyoming, Laramie, Wyoming, USA.

Carlisle, J. D., and A. D. Chalfoun. 2020. The abundance of Greater Sage-Grouse as a proxy for the abundance of sagebrush-associated songbirds in Wyoming, USA. Avian Conservation and Ecology 15(2):16. tools:::Rd_expr_doi("10.5751/ACE-01702-150216")

See Also

sparrowSiteData, sparrowDetectionData, RdistDf

Examples

if (FALSE) {
# The following code generated 'sparrowDf'
data(sparrowDetectionData)
data(sparrowSiteData)
sparrowDf <- RdistDf(transectDf = sparrowSiteData
                   , detectionDf = sparrowDetectionData
                   , by = "siteID"
                   , pointSurvey = FALSE
                   , .effortCol = "length"
                    )
}

data(sparrowDf)
tidyr::unnest(sparrowDf, detections)  # only non-zero transects
Rdistance::unnest(sparrowDf) # with zero transects at the bottom
summary(sparrowDf,
  formula = dist ~ groupsize(groupsize)
)