gorillas {spatstat}R Documentation

Gorilla Nesting Sites

Description

Locations of nesting sites of gorillas, and associated covariates, in a National Park in Cameroon.

Usage

data(gorillas)

Format

gorillas is a marked point pattern (object of class "ppp") representing nest site locations.

gorillas.extra is a named list of 7 pixel images (objects of class "im") containing spatial covariates. It also belongs to the class "listof".

All spatial coordinates are in metres. The coordinate reference system is WGS_84_UTM_Zone_32N.

Details

These data come from a study of gorillas in the Kagwene Gorilla Sanctuary, Cameroon, by the Wildlife Conservation Society Takamanda-Mone Landscape Project (WCS-TMLP). A detailed description and analysis of the data is reported in Funwi-Gabga and Mateu (2012).

The dataset gorillas is a marked point pattern (object of class "ppp") giving the spatial locations of 647 nesting sites of gorilla groups observed in the sanctuary over time. Locations are given as UTM (Zone 32N) coordinates in metres. The observation window is the boundary of the sanctuary, represented as a polygon. Marks attached to the points are:

group

Identifier of the gorilla group that constructed the nest site: a categorical variable with values major or minor.

season

Season in which data were collected: categorical, either rainy or dry.

date

Day of observation. A value of class "Date".

The accompanying dataset gorillas.extra contains spatial covariate information. It is a named list containing seven pixel images (objects of class "im") giving the values of seven covariates over the study region. It also belongs to the class "listof" so that it can be plotted. The component images are:

aspect

Compass direction of the terrain slope. Categorical, with levels N, NE, E, SE, S, SW, W and NW.

elevation

Digital elevation of terrain, in metres.

heat

Heat Load Index at each point on the surface (Beer's aspect), discretised. Categorical with values Warmest (Beer's aspect between 0 and 0.999), Moderate (Beer's aspect between 1 and 1.999), Coolest (Beer's aspect equals 2).

slopeangle

Terrain slope, in degrees.

slopetype

Type of slope. Categorical, with values Valley, Toe (toe slope), Flat, Midslope, Upper and Ridge.

vegetation

Vegetation or cover type. Categorical, with values Disturbed (highly disturbed forest), Colonising (colonising forest), Grassland (savannah), Primary (primary forest), Secondary (secondary forest), and Transition (transitional vegetation).

waterdist

Euclidean distance from nearest water body, in metres.

For further information see Funwi-Gabga and Mateu (2012).

Source

Field data collector: Wildlife Conservation Society Takamanda-Mone Landscape Project (WCS-TMLP). Please acknowledge WCS-TMLP in any use of these data.

Data kindly provided by Funwi-Gabga Neba, Data Coordinator of A.P.E.S. Database Project, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.

The collaboration of Prof Jorge Mateu, Universitat Jaume I, Castellon, Spain is gratefully acknowledged.

References

Funwi-Gabga, N. (2008) A pastoralist survey and fire impact assessment in the Kagwene Gorilla Sanctuary, Cameroon. M.Sc. thesis, Geology and Environmental Science, University of Buea.

Funwi-Gabga, N. and Mateu, J. (2012) Understanding the nesting spatial behaviour of gorillas in the Kagwene Sanctuary, Cameroon. Stochastic Environmental Research and Risk Assessment, in press.

Examples

  summary(gorillas)
  plot(gorillas)
  plot(gorillas.extra)

[Package spatstat version 1.25-3 Index]