Data and code from: Spatial ecology of the Turks & Caicos boa, Chilabothrus c. chrysogaster Cope, 1871 (Serpentes: Boidae)
Data files
Abstract
Obtaining ecological and natural history data from cryptic squamates can be challenging, but is crucial to understanding species’ biology, particularly in the context of conservation. In the Greater Antilles, this challenge is especially apparent, particularly among the West Indian boas (genus Chilabothrus). Most species have had only minimal natural history study, with a few exceptions. The Turks & Caicos boa (C. chrysogaster) has been studied intensively for over 16 years on the small privately owned island of Big Ambergris Cay, Turks and Caicos Islands. We conducted a multi-year radio-tracking study on the species to generate information relevant to spatial habitat use and movement that will inform conservation decision-making in the face of increasing development pressure. We tracked a total of 19 female snakes using surgically implanted transmitters, enabling us to obtain between 16 and 40 location observations per boa over the lifetime of each transmitter. We estimated home ranges, the core space used by an animal, using range distributions, finding that females have a home range of 0.70 ha to 1.2 ha. We also estimated occurrence distributions, the use of space between specific time intervals, finding an average occurrence area of 1.62 ha. Several females overlapped in their spatial habitat use, and we observed female boas using two novel habitats for the species (iron shore wrack and red mangrove). This study provides valuable information on the spatial ecology of an endangered boa and will serve to inform conservation work that is currently underway.
README: Data from: Spatial Ecology of the Turks & Caicos Boa, Chilabothrus c. chrysogaster Cope, 1871 (Serpentes: Boidae)
1) Data file (boas2.csv) and R code (R_Code__Reynolds_etal_2023.r) to run basic spatial statistics
This data file contains latitude and longitude for each snake for each encounter. The date, time, and snake ID are included as columns. The R code will allow a user to calculate distances traveled, as well as basic KUD calculations. Each row is a single observation of a snake, identified in the the name column.
2) Data files to run spatial statistics with the package ctmm. See the external CTMM package help file for column naming conventions.
This folder contains the following data files:
boa_telem_data.csv. This file contains the telemetry data for all boas, formatted into the input format for ctmm. Each row is a single snake observation, identified by the event-id. Other columns include visible (was the snake found), the timestamp in CTMM format, the lat/long coordinates in decimal degrees, the tag-name of each snake, and the study name.
range_resident.csv. This file contains the telemetry data for boas that were determined to be range resident in ctmm. These data should be used for final ctmm analyses. The data structure is equivalent to boa_telem_data.csv, but has been filtered to only include range-resident boas.
overlap.X.csv. These files are individual files for each pair of range-resident boas that overlap ranges, used to calculate range overlap using AKDE. The boa names are included in the data file name. The rest of the data file is equivalent to boa_telem_data.csv, but has been filtered to only include a pair of overlapping boas.
3) Data files to run spatial statistics with the package bbmm. See the external BBMM package help files for column naming and data type.
This data folder contains one csv file for each snake in the study, with the snake name included in the data file name. Within each cscv file, each row is a single observation of a snake, identified in the name column. The date and time of the observation are included. The column named rounded is the time rounded to the nearest hour. The lat and long coordinates in decimal degrees are given. The time lag(hrs) column is a vector of time differences in hours between successive locations of the snake. In other words, how long between each location given in each column.
4) R code to run all CTMM package analyses.
R code to run spatial statistics with the package bbmm. The code allows a user to run a BBMM analysis for each snake.
Description of the data and file structure
There are datafiles organized by R package usage that can be loaded directly into R using the scripts provided.
Datafiles are organized by folder, with each folder corresponding to a package in R and a set of scripts.
Sharing/Access information
Links to other publicly accessible locations of the data:
* none
Data was derived from the following sources:
* none
Code/Software
1) R script to run basic spatial stats (R_Code__Reynolds_etal_2023.r)
2) R script to run spatial statistics with the package ctmm (R_Code_ctmm_Reynolds_etal_2023.r)
3) R script to run spatial statistics with the package bbmm (bbmm_code.r)
Methods
Snake radio telemetry.
Usage notes
R v. 4.2.3.