R/lion_reproduction.R

In ecoteach: Educational Datasets for Ecology and Agriculture

#' Galapagos Sea Lion Reproduction Data
#'
#' This dataset contains reproductive performance data for female Galapagos sea lions
#' (Zalophus wollebaeki) collected over a 13-year period in the Galapagos archipelago.
#' The data includes information on mother birth dates, body mass, age at first reproduction,
#' and offspring details. This dataset was used to study life history traits and 
#' reproductive trade-offs of this tropical apex predator in an unpredictable habitat.
#'
#' @format A data frame with 48 rows and 12 variables:
#' \describe{
#'   \item{MotherID}{Unique identifier for the mother sea lion}
#'   \item{MotherBD}{Mother's birth date}
#'   \item{exact}{Whether the birth date is exact ("Yes"), estimated ("No"), or unknown ("Unknown")}
#'   \item{MotherBirthyear}{Year the mother was born}
#'   \item{AgeAtCapture}{Age of the mother when first captured (in days)}
#'   \item{AverageOneYearBodymass}{Average body mass of the mother at one year of age (in kg)}
#'   \item{PupID}{Unique identifier for the pup}
#'   \item{FirstPupBorn}{Date when the first pup was born}
#'   \item{OffspringSex}{Sex of the offspring ("Male" or "Female")}
#'   \item{SeenSince}{Year the mother was first observed}
#'   \item{SeenUntil}{Year the mother was last observed}
#'   \item{AFR}{Age at first reproduction (in years)}
#' }
#' @source Kalberer, Stephanie, Meise, Kristine, Trillmich, Fritz, & Krüger, Oliver (2018). 
#'   Reproductive performance of a tropical apex predator in an unpredictable habitat. 
#'   Dryad Digital Repository.
#'   \doi{10.5061/DRYAD.6S48579}
#' @examples
#' \donttest{
#' # Load the dataset
#' data(lion_reproduction)
#' 
#' # Basic exploration
#' head(lion_reproduction)
#' summary(lion_reproduction)
#' 
#' # Calculate mean age at first reproduction
#' mean(lion_reproduction$AFR)
#' 
#' # Compare age at first reproduction by offspring sex
#' boxplot(AFR ~ OffspringSex, data = lion_reproduction,
#'         main = "Age at First Reproduction by Offspring Sex",
#'         ylab = "Age (years)")
#'         
#' # Relationship between mother's body mass and age at first reproduction
#' plot(AverageOneYearBodymass ~ AFR, data = lion_reproduction,
#'      main = "Body Mass vs. Age at First Reproduction",
#'      xlab = "Age at First Reproduction (years)",
#'      ylab = "Average Body Mass at One Year (kg)")
#' }
"lion_reproduction"