greenWoodpecker {AHMbook}

Count data from the Swiss Breeding Bird Survey for Green Woodpeckers from 2004 to 2017

Description

The Swiss breeding bird survey ("Monitoring Häufige Brutvögel" MHB) has monitored the populations of approximately 150 common species since 1999. The MHB sample consists of 267 1-km squares that are laid out as a grid across Switzerland. Fieldwork is conducted by about 200 skilled birdwatchers annually, most of them volunteers. Avian populations are monitored using a simplified territory mapping protocol (also called spot-mapping West of the Atlantic), where each square is surveyed up to three times during the breeding season (only twice above the tree line around 2000 m elevation). Surveys are conducted along a transect that does not change over the years and is 4-6 kms in length on average.

The data frame greenWoodpecker has count data for Green Woodpeckers Picus viridis from 2004 to 2017. There are some missing values: see Details.

Usage

data("greenWoodpecker")

Format

greenWoodpecker is a data frame with 267 rows and 146 columns:

x, y

the x and y coordinates of the center of the quadrat; the coordinate reference system intentionally not specified.

nsurveys

the number of replicate surveys planned in the quadrat; above the tree-line 2, otherwise 3.

elevation

the mean elevation of the quadrat, m.

forest

percentage forest cover

route.length

the length of the route

X2004.1.count to X2017.3.count

number of territories observed for each survey; 2004.1 indicates the first survey in 2004.

X2004.1.date to X2017.3.date

Julian date of the survey, 1 = a weekend near 15 April.

X2004.1.time to X2017.3.time

time spent in the quadrat during the survey, mins.

X2004.observer to X2017.observer

numerical code identifying the observer.

Details

Missing values in the count and date columns indicate that the corresponding survey was not carried out.

On 26 occasions when surveys were carried out, the time taken was not recorded, resulting in additional NAs in the time columns.

Source

Swiss Ornithological Institute

References

Kéry, M. & Royle, J.A. (2021) Applied Hierarchical Modeling in Ecology AHM2 - 2.2.

Examples

data(greenWoodpecker)
str(greenWoodpecker)