AHMbook (version 0.2.10)

EurasianLynx: Data for Eurasian lynx from Switzerland and Italy (only Alps).

Description

The data are observations of Eurasian lynx (Lynx lynx) confirmed by experts and by the general public (and not confirmed by experts), summarized to a 10 x 10 km grid and for 3 occasions during a 'winter' (Nov-Dec, Jan-Feb, Mar-Apr). The observations are classified as 'certain' or 'uncertain', and only the latter are assumed to be contaminated with false positives (but both are subject to false-negative errors). This data set covers the Alps in Switzerland and Italy from 1994 to 2016.

Usage

data("EurasianLynx")

Format

EurasianLynx is a data frame with 43,332 rows corresponding to observations, and 10 columns:

type

factor: 'certain' or 'uncertain'.

site.nr

site (10 x 10 km cell) identifier.

y.1, y.2, y.3

detection (1)/non-detection (0) for the three occasions.

Year

the year of the observation.

Cntry

the country, 'Italy' or 'Switzerland'.

xcoord

the x coordinate of the cell, km E of the origin.

ycoord

the y coordinate of the cell, km N of the origin.

forest

the percentage forest cover in the cell.

References

Molinari-Jobin, A., Kéry, M., Marboutin, E., Molinari, P., Koren, I., Fuxjäger, C., Breitenmoser-Würsten, C., Wölfl, S., Fasel, M., Kos, I., Wölfl, M., & Breitenmoser, U. (2012) Monitoring in the presence of species misidentification: the case of the Eurasian lynx in the Alps. Animal Conservation, 15, 266-273.

Kéry, M. & Royle, J.A. (2021) Applied Hierarchical Modeling in Ecology AHM2 - 7.3.2 and 9.6.1.3.

Examples

data(EurasianLynx)
lynx <- EurasianLynx # Shorter name
str(lynx)

# Create additional columns needed for the analysis in 'unmarked':
lynx$occ.1 <- 1
lynx$occ.2 <- 2
lynx$occ.3 <- 3
lynx$sYear <- standardize(lynx$Year)
str(lynx)