Analyse Mark-Release-Recapture Data from Sterile Insect Technique (SIT) Field Experiments

Overview

sit is a R-package currently on active development, after a thorough analysis of requirements.

Import data about traps, release events and field surveys into a sit object. Then, query the sit object for estimates of competitiveness, dispersal, survival and wild-population density.

sit outline

Example

First, you need to load the package.

library(sit)

We use some fake data for demonstration purposes. See ?fake_sit.

Trap data: set up a sf table of points with trap coordinates (see, st_as_sf(), for instance), identification code, type (see sit_trap_types()) and area (sit/control). Use sit_traps() to import into a sit_traps object.

fake_traps
#> Simple feature collection with 5 features and 3 fields
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: -1 ymin: -1 xmax: 2 ymax: 2
#> CRS:           NA
#>   id type    area      geometry
#> 1  a  OVT     sit   POINT (1 1)
#> 2  b  BGS     sit   POINT (2 1)
#> 3  c  HLC     sit   POINT (1 2)
#> 4  d  BGS     sit   POINT (2 2)
#> 5  e  OVT control POINT (-1 -1)

my_traps <- sit_traps(fake_traps)

Release events: releases can be performed from a single point or homogeneously over the sit area. Set up a table with release dates, colour and number of individuals. For point releases include release coordinates and make it a sf object. Lacking geographical coordinates, sit will interpret it as a areal release.

fake_rpoints
#> Simple feature collection with 3 features and 3 fields
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: 1 ymin: 1 xmax: 2 ymax: 2
#> CRS:           NA
#>         date colour     n    geometry
#> 1 2019-11-25 yellow 10000 POINT (1 2)
#> 2 2019-12-01    red 10000 POINT (2 1)
#> 3 2019-12-13   blue 10000 POINT (1 2)

fake_rareal
#>         date colour    n
#> 1 2019-12-21   pink 1000
#> 2 2020-01-09 purple 1000

Use sit_revents() to import into sit_revents objects and combine different release types into a single sit_revents object with c().

my_releases <- c(
  sit_revents(fake_rpoints),
  sit_revents(fake_rareal)
)

Field survey data: field data are collected at adult or egg stages of development, depending on the trap type (see sit_trap_types())

Field data from adult surveys can be imported using sit_adult_surveys() from a table such as:

fake_adults
#>   trap     survey duration population species    sex  n
#> 1    b 2019-12-16        7       blue     aeg   male 10
#> 2    d 2019-11-27        7     yellow     aeg   male 20
#> 3    c 2019-11-27        7       wild     aeg female 30
#> 4    d 2019-12-25        7       pink     aeg   male 40
#> 5    d 2019-12-25        7       wild     aeg   male 50

my_asurveys <- sit_adult_surveys(fake_adults)

Field data from egg surveys, include other information such as the hatching rate:

fake_eggs
#>   trap     survey duration fertile  n
#> 1    a 2019-12-01        7    TRUE 15
#> 2    a 2019-12-22        7   FALSE 30
#> 3    a 2019-12-22        7    TRUE 45
#> 4    e 2019-11-15        7    TRUE 60

my_eggsurveys <- sit_egg_surveys(fake_eggs)

Combine all the information into a sit object using sit():

my_sit <- sit(
  traps          = my_traps,
  release_events = my_releases,
  adult_surveys  = my_asurveys,
  egg_surveys    = my_eggsurveys
)

Query your sit object for estimates of competitiveness, dispersal, survival and wild-population density.

This toy example requires disabling the spatial_adjustment because there are too few traps in this unrealistic situation. But this is not the case in general. See Retrieving Results for details on the spatial adjustment.

sit_competitiveness(my_sit)
#> 
#> ── Sterile male competitiveness ────────────────────────────────────────────────
#> ℹ Estimated value: 1.92
#> 
#> 
#> Component                         Value
#> -------------------------------  ------
#> Sterile-wild male ratio            0.80
#> Natural fertility                  1.00
#> Observed fertility in SIT area     0.40
#> Sterile fertility (assumed)        0.01

sit_mdt(my_sit, spatial_adjustment = FALSE)
#> 
#> ── Mean Distance Travelled ─────────────────────────────────────────────────────
#> 
#> 
#> population    age    mdt
#> -----------  ----  -----
#> blue            3   1.41
#> yellow          2   1.00

sit_flight_range(my_sit, spatial_adjustment = FALSE, pool = TRUE)
#> 
#> ── Flight range ────────────────────────────────────────────────────────────────
#> 
#> 
#> population    level   cum_adj_catch     FR
#> -----------  ------  --------------  -----
#> pooled           50              15   0.82
#> pooled           90              27   1.28

sit_diffusion(my_sit, spatial_adjustment = FALSE)
#> 
#> ── Diffusion coefficient ───────────────────────────────────────────────────────
#> 
#> 
#> population    Dest
#> -----------  -----
#> blue          0.17
#> yellow        0.12

sit_survival(my_sit, spatial_adjustment = FALSE, pool = TRUE)
#> 
#> ── Survival ────────────────────────────────────────────────────────────────────
#> 
#> 
#> population    N_released    PDS    ALE   RRx1e3     SR
#> -----------  -----------  -----  -----  -------  -----
#> pooled             20000   0.52   1.55     3.81   0.53

sit_wild_size(my_sit, pool = TRUE)
#> 
#> ── Wild male population size ───────────────────────────────────────────────────
#> 
#> 
#> population      p_est   p_sd
#> -----------  --------  -----
#> pooled        1901.71     NA

Installation

options(repos = c(
  ciradastre = 'https://cirad-astre.r-universe.dev',
  CRAN = 'https://cloud.r-project.org'))

install.packages("sit")

This installs binary packages for Windows and MacOS, unless you configured R to install source packages. In such case, see below.

Linux and source installation

sit uses the geospatial libraries GDAL, GEOS and Proj.4, via the R-package sf.

Dependencies for recent versions of Ubuntu (18.04 and later) are available in the official repositories; you can install them with:

apt-get -y update && apt-get install -y  libudunits2-dev libgdal-dev libgeos-dev libproj-dev

For Fedora, Arch or source installation in Windows or Mac, please refer to the installation instructions for sf.

Getting help online

Bug reports and feature requests should be posted on GitLab using the issue system.

For support, reach out in the sit mailing list. Archives are of public access.

Contributions are welcome via pull requests.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.

Overview

Example

Installation

Linux and source installation

Getting help online