Map: animal home ranges

These functions extract 'home range' estimates from a SpatRaster that describes the intensity of movements within an area.

map_hr_prop(.map, .prop = 0.5, .add = FALSE, ...)

map_hr_core(.map, .add = FALSE, ...)

map_hr_home(.map, .add = FALSE, ...)

map_hr_full(.map, .add = FALSE, ...)

Arguments

.map

A SpatRaster (utilisation distribution).

.prop

For map_hr_prop(), .prop is a number that defines the range proportion.

.add

A logical variable that defines whether or not to add a polygon of the range to an existing map.

...

If .add = TRUE, ... is a place holder for additional arguments passed to terra::plot().

Value

The functions return a SpatRaster. Cells with a value of one are inside the specified range boundaries; cells with a value of zero are beyond range boundaries. If .add is TRUE, the boundaries are added to an existing plot.

Details

These functions are modelled on flapper::map_hr_*() functions, where full details are provided.

See also

map_*() functions build maps of space use:

• map_pou() maps probability-of-use;

• map_dens() maps point density;

• map_hr_*() functions map home ranges;

All maps are represented as SpatRasters.

To derive coordinates for mapping patterns of space use for tagged animals, see:

• coa() to calculate centre-of-activity;

• pf_filter() and associates to sample locations using particle filtering;

Author

Edward Lavender

Examples

library(terra)
#> Warning: package ‘terra’ was built under R version 4.3.3
#> terra 1.7.78
#> 
#> Attaching package: ‘terra’
#> The following objects are masked from ‘package:spatstat.geom’:
#> 
#>     area, delaunay, is.empty, rescale, rotate, shift, where.max,
#>     where.min
#> The following objects are masked from ‘package:testthat’:
#> 
#>     compare, describe
#> The following object is masked from ‘package:data.table’:
#> 
#>     shift

#### Set up example
# Define hypothetical input SpatRaster
r <- rast()
n <- ncell(r)
i <- 2e4
r[i] <- 1
r <- distance(r)
#> 
|---------|---------|---------|---------|
=========================================
                                          

r <- r / global(r, "sum")[1, 1]
plot(r)

#### Examples
map <- map_hr_full(r, .add = TRUE, lwd = 5)
map <- map_hr_home(r, .add = TRUE, border = "blue")
map <- map_hr_core(r, .add = TRUE, border = "orange")
map <- map_hr_prop(r, .prop = 0.2, .add = TRUE, border = "red")