In hugo-marques/ORFID: Manage and Summarize Data from Oregon RFID ORMR and ORSR Antenna Readers

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

library(dplyr)
original <- options("tibble.width")
options(tibble.width = Inf)

Overview

ORFID is a package for compiling and summarizing passive integrated transponder (PIT) data collected using Oregon RFID (radio-frequency identification) ORMR (Oregon RFID Multi-Reader) and ORSR (Oregon RFID Single Reader) antenna readers.

library(ORFID)

View field names

The output from Oregon RFID antenna readers is highly customizable. Available data fields and their descriptions can be viewed using field_names().

field_names()

Loading the data

ORFID requires raw (unedited) data downloaded directly from Oregon RFID ORMR and ORSR antenna readers. Data files must be delimited by tab, comma, or semicolon; space delimited data are not supported.

Data are loaded using one of three import functions:

• import_ORFID(): Imports detection records from ORMR and ORSR antenna readers
• import_ORFID_events(): Imports event data from ORMR and ORSR antenna readers
• import_old_readers(): Imports detection data from previous generations of Oregon RFID antenna readers

dat <- import_ORFID(file = "~/reader_1.txt", delim = "\t")
events <- import_ORFID_events(file = "~/reader_1.txt", delim = "\t")
old_dat <- import_old_readers(file = "~/old_reader.txt", delim = "\t")

Joining data into arrays

Multiple data files can be combined into an array representing all antennas within a designated study region. Individual files are combined into a list and joined using join_multireader_data(). A new data field is created, LOC, which combines the site code (SCD) and antenna number (ANT) into a unique location variable.

reader_1 <- import_ORFID(file = "reader_1.txt", delim = "\t")
reader_2 <- import_ORFID(file = "reader_2.txt", delim = "\t")
reader_3 <- import_ORFID(file = "reader_3.txt", delim = "\t")

dat_multi <- join_multireader_data(list(reader_1, reader_2, reader_3))

Summarize data

Data from import_ORFID() or join_multireader_data() can be summarized to view site information and tag detections.

site_summary(dat_multi)

tag_summary(dat_multi)

View marker tag data

Marker tags are stationary tags used to constantly monitor the effectiveness of Oregon RFID antenna readers. Marker tags are detected at regular time intervals, which are set by the user.

Data from individual marker tags can be viewed and plotted using ORFID marker tag functions. The optional gap argument represents the minimum time gap between detections. If gap is specified, only detections where the time gap was greater than gap are retained by marker_tag(), and periods where the time gap was greater than gap are highlighted in red by marker_tag_plot(). This allows the user to identify periods when marker tags were not detected as frequently as expected.

The plot object produced by marker_tag_plot() is a ggplot2 object, and can be edited using additional ggplot2 functions, such as theme().

marker_tag(dat_multi, tag = "0000_000000005972")

marker_tag_plot(dat_multi, tag = "0000_000000005972", gap = 60*10) # Ten minute time gap

Summarize directional data

PIT antennas are sometimes deployed along a linear migration route to monitor the directional movement of tagged individuals. ORFID has several functions that can be used to summarize directional data.

tag_direction() is used to determine the direction of movement whenever an individual is detected at a new/subsequent antenna. The function requires a vector describing the order of locations an individual encounters as it travels along a directional gradient (e.g., from downstream to upstream). The column, DIR, is created, where U and D designate upstream and downstream movements, respectively, and S designates a consecutive detection at the same antenna.

For example, a study array is composed of two antennas, downstream_A1 and upstream_A1, and animals move in an upstream direction (i.e., passing over the downstream antenna, then the upstream antenna).

dat_multi <- join_multireader_data(list(reader_us, reader_ds), verbose = FALSE)

tag_direction(dat_multi, LOC_vec = c("downstream_A1", "upstream_A1")) %>% 
    filter(TAG == "900_228000369764")

direction_summary() can then be used to summarize the time difference between the first and last detections for each unique tag within the system. For example, this function can be used to determine residence time above or below an antenna.

direction_summary() has an optional argument include_stationary. If include_stationary = TRUE, all detections will be included in the summary. For example, if a tag is detected multiple times at the same antenna before making an upwards movement, its first direction is stationary. If include_stationary = FALSE, only detections with known direction will be included. For example, if a tag is detected multiple times at the same antenna before making an upwards movement, the stationary movements will be ignored and its first direction will be up.

dir <- tag_direction(dat_multi, LOC_vec = c("downstream_A1", "upstream_A1"))

direction_summary(dir)

direction_summary(dir, include_stationary = TRUE)

ant_efficiency() is used to determine the efficiency for each antenna within a directional array. As with tag_direction(), a vector is required that describes the order of locations an individual encounters along a linear migration route. Efficiency is calculated as the number of shared detections at location x and at any location after x, divided by the number of detections after location x. Efficiency cannot be calculated for the final antenna as there are no subsequent detections. Reversing the order of the location vector can inform efficiency in systems with movement in multiple directions.

ant_efficiency(dat_multi, LOC_vec = c("downstream_A1", "upstream_A1"))

Export data

Any data frame created using ORFID functions can be exported to the working directory as a .csv or .xlsx file.

export_ORFID(dat_multi, name = "multi_data_compiled", extension = ".xlsx")

options(tibble.width = original)

hugo-marques/ORFID documentation built on Jan. 10, 2023, 6:26 a.m.