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camtrapR (version 0.99.0)

spatialDetectionHistory: Generate a capthist object for spatial capture-recapture analyses from camera-trapping data

Description

This function generates spatial detection histories of individuals of a species for spatial capture-recapture analyses with package secr. Data are stored in a capthist object. The capthist object contains detection histories, camera-trap station location and possibly individual and station-level covariates. Detection histories can have adjustable occasion length and occasion start time (as in the function detectionHistory]).

Usage

spatialDetectionHistory(recordTableIndividual, 
  species, 
  camOp, 
  CTtable,
  output,
  stationCol = "Station", 
  speciesCol = "Species",
  Xcol,
  Ycol,
  stationCovariateCols,
  individualCol,
  individualCovariateCols,
  recordDateTimeCol = "DateTimeOriginal",
  recordDateTimeFormat = "%Y-%m-%d %H:%M:%S",
  occasionLength, 
  occasionStartTime = 0, 
  maxNumberDays,
  day1,
  buffer,
  includeEffort = TRUE,
  scaleEffort = FALSE,
  binaryEffort,
  timeZone,
  makeRMarkInput
)

Arguments

recordTableIndividual
data.frame. the record table with individual IDs created by recordTableIndividual
species
character. the species for which to compute the detection history
camOp
The camera operability matrix as created by cameraOperation
CTtable
data.frame. contains station IDs and coordinates. Same as used in cameraOperation.
output
character. Return individual counts ("count") or binary observations ("binary")?
stationCol
character. name of the column specifying Station ID in recordTableIndividual and CTtable
speciesCol
character. name of the column specifying species in recordTableIndividual
Xcol
character. name of the column specifying x coordinates in CTtable
Ycol
character. name of the column specifying y coordinates in CTtable
stationCovariateCols
character. name of the column(s) specifying station-level covariates in CTtable
individualCol
character. name of the column specifying individual IDs in recordTableIndividual
individualCovariateCols
character. name of the column(s) specifying individual covariates in recordTableIndividual
recordDateTimeCol
character. name of the column specifying date and time in recordTableIndividual
recordDateTimeFormat
format of column recordDateTimeCol in recordTableIndividual
occasionLength
integer. occasion length in days
occasionStartTime
integer. time of day (the full hour) at which to begin occasions.
maxNumberDays
integer. maximum number of trap days per station (optional)
day1
character. When should occasions begin: station setup date ("setup"), first day of survey ("survey"), a specific date (e.g. "2015-12-31")?
buffer
integer. Makes the first occasion begin a number of days after station setup. (optional)
includeEffort
logical. Include trapping effort (number of active camera trap days per station and occasion) as usage in capthist object?
scaleEffort
logical. scale and center effort matrix to mean = 0 and sd = 1?
binaryEffort
logical. Should effort be binary (1 if >1 active day per occasion, 0 otherwise)?
timeZone
character. must be an argument of OlsonNames
makeRMarkInput
logical. If FALSE, output will be a data frame for RMark. If FALSE or not specified, a secr capthist object

Value

  • Output depends on argument makeRMarkInput:
  • makeRMarkInput = FALSEA capthist object
  • makeRMarkInput = TRUEA data frame for use in RMark

Details

The function creates a capthist object by combining three different objects: 1) a record table of identified individuals of a species, 2) a camera trap station table with station coordinates and 3) a camera operation matrix computed with cameraOperation. The record table must contain a column with individual IDs and optionally individual covariates. The camera trap station table must contain station coordinates and optionally station-level covariates. The camera operation matrix provides the dates stations were active or not and the number of active stations. day1 defines if each stations detection history will begin on that station's setup day (day1 = "station") or if all station's detection histories have a common origin (the day the first station was set up if day1 = "survey" or a fixed date if, e.g. day1 = "2015-12-31"). includeEffort controls whether an effort matrix is computed or not. If TRUE, effort will be used for object usage) information in a traps). scaleEffort and binaryEffort further define the behaviour. The number of days that are aggregated is controlled by occasionLength. occasionStartTime can be used to make occasions begin another hour than midnight (the default). This may be relevant for nocturnal animals, in which 1 whole night would be considered an occasion. Output can be returned as individual counts per occasion (output = "count") or as binary observation (output = "binary"). capthist objects (as created by spatialDetectionHistory for spatial capture-recapture analyses) expect the units of coordinates (Xcol and col in CTtable) to be meters.

See Also

secr RMark

Examples

Run this code
data(recordTableIndividualSample)
data(camtraps)

# create camera operation matrix (with problems/malfunction)
camop_problem <- cameraOperation(CTtable      = camtraps,
                                 stationCol   = "Station",
                                 setupCol     = "Setup_date",
                                 retrievalCol = "Retrieval_date",
                                 writecsv     = FALSE,
                                 hasProblems  = TRUE,
                                 dateFormat   = "%d/%m/%Y"
)

sdh <- spatialDetectionHistory(recordTableIndividual = recordTableIndividualSample, 
                               species               = "LeopardCat",    
                               camOp                 = camop_problem, 
                               CTtable               = camtraps,
                               output                = "binary",
                               stationCol            = "Station",
                               speciesCol            = "Species",
                               Xcol                  = "utm_x",
                               Ycol                  = "utm_y",
                               individualCol         = "Individual",
                               recordDateTimeCol     = "DateTimeOriginal",
                               recordDateTimeFormat  = "%Y-%m-%d %H:%M:%S",
                               occasionLength        = 10, 
                               day1                  = "survey",
                               includeEffort         = TRUE,
                               timeZone              = "Asia/Kuala_Lumpur"
  )
  
# missing space in species = "LeopardCat" was introduced by recordTableIndividual 
# (because of CRAN package policies. 
# In your data you can have spaces in your directory names)

  summary(sdh)
  plot(sdh, tracks = TRUE)

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