data_rodli {Petersen}

Capture-recapture experiment at Rodli Tarn.

Description

Ricker (1975) gives an example of work by Knut Dahl on estimating the number of brown trout (Salmo truitta) in some small Norwegian tarns. Between 100 and 200 trout were caught by seining, marked by removing a fin (an example of a batch mark) and distributed in a systematic fashion around the tarn to encourage mixing. A total of n_1=109 fish were captured, clipped and released, n_2=177 fish were captured at the second occasion, and m_2=57 marked fish were recovered.

Usage

data(data_rodli)

Format

data_rodli

A data frame with 3 rows and 2 columns:

cap_hist.

Capture history (10, 01, or 11). Note that n_{10}=n_1-m_2; n_{01}=n_2-m_2; and n_{11}=m_2

freq.

Number of fish with this history