fit.cr: Capture-recapture estimation

Description Usage Arguments Value

View source: R/crfunctions.R

Description

Estimates abundance using capture-recapture methods. Five methods are implemented: M0, Mt, Mb, Mtb and Mh (see argument model.)

Usage

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
fit.cr(
  ch,
  model,
  alpha = 0.05,
  start.n0 = NULL,
  start.p = NULL,
  start.b = NULL,
  start.mu1 = NULL,
  start.mu2 = NULL,
  start.phi = NULL
)

Arguments

ch

Binary capture history matrix, with rows being individuals and columns being occasions.

model

One of

  • 'M0' Model with constant capture probability.

  • 'Mt' Model with differewnt capture probability on each occasion.

  • 'Mb' Model with behavioural response to capture that increases or decreases capture probability after first capture.

  • 'Mtb' Model with differewnt capture probability on each occasion and behavioural response to capture that increases or decreases capture probability after first capture.

  • 'Mh2' Model a finite 2-part mixture capture probability, i.e. 2 levels of latent capture probability.

alpha

The significance level for confidence intervals (defaults to alpha=0.05 for 95% level)

start.n0

Starting value for number of undetected animals for numerical optimisation of likelihood.

start.p

Starting value for detection probability for numerical optimisation of likelihood. For model Mt all probabilities are assumed to be the same to start with.

start.b

Starting value for the behavioural effect of capture. Positive means capture increases detection probability, negative decreases. (start.b is the multiplicative effect of previous capture on the ODDS of capture, i.e. on p/(1-p).)

start.mu1

Starting value for number of undetected animals for numerical optimisation of likelihood.

start.mu2

Starting value for the second latent capture probability in model Mh2.

start.phi

Starting value for the proportion of the population that has the first level of the latent capture probability.

Value

The function returns a list with the following elements:


david-borchers/mt5751a documentation built on Feb. 22, 2021, 4:01 a.m.