Map: animal home ranges

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

Usage

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 terra::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 terra::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.

On Linux, these functions cannot be used within a Julia session.

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 terra::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

if (patter_run(.julia = FALSE, .geospatial = TRUE)) {

  #### Set up example
  # Define hypothetical input SpatRaster (probability distribution)
  r    <- terra::setValues(dat_gebco(), NA)
  i    <- 24073
  r[i] <- 1
  r    <- terra::distance(r)
  r    <- terra::mask(r, dat_gebco())
  r    <- r / terra::global(r, "sum", na.rm = TRUE)[1, 1]
  terra::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")

}