est_emigrants: Estimate juvenile emigrant abundance from M-R data.

In ryankinzer/cuyem: Snake River Basin Anadromous Fish Summaries and Metric Estimation

Estimate juvenile emigrant abundance from M-R data.

Description

emigrant_abundance generates stratified juvenile abundance estimates from M-R data collected at rotary screw traps (RST). The function operates similar to a Gauss based program developed by Steinhorst et al. (2004). Point estimates are derived using the Bailey estimator and uncertainty is obtained by bootstrapping unmarked captures and marked recaptures.

Usage

est_emigrants(
  data,
  unmark,
  mark,
  recap,
  alpha = 0.05,
  iter = 1000,
  boot_values = FALSE,
  print = FALSE
)

Arguments

data	An R dataframe containing at least three fields of data; the count of "unmark", "mark", and "recap" fish captured in the trap. Each row of the #' data is treated as an independent strata. Grouping variables can also be included in the data (e.g., trap season or life-stage).
alpha	Type I error rate. Default is set at 0.05 to produce 95% confidence intervals.
iter	The number of bootstrap iterations to be run. Default is set at 1000.

Value

A list of point and uncertainty estimates by each strata.

Warning

Standard error and confidence intervals will not match GAUSS estimates perfectly because of bootstrapped sample distribution.

Author(s)

Ryan N. Kinzer

Examples

u <- c(76, 128, 82, 61, 350, 74)
m <- c(68, 117, 70, 42, 282, 64)
r <- c(7, 10, 9, 18, 48, 10)

dat <- data.frame('u' = u, 'm' = m, 'r' = r)
est_strata <- est_emigrants(data = dat, alpha = .05,iter = 1000, print=TRUE)
est_strata$Strata

ryankinzer/cuyem documentation built on April 20, 2024, 2:10 p.m.