sufficient recaptures

[Lynxlady]

In the course of the application of secr, the question of the number of "sufficient" recaptures for robust density estimates came up, as the species we analyse (Eurasian lynx, Lynx lynx) occurs in very low densities in our area (approximately 1/100km2). We foundthe statement in Efford 2009 of "at least 20 recaptures". Unfortunately there are several ways for us to interpret this statement:

1. 20 recaptures could mean that every lynx needs at least 20 recaptures.

2. 20 recaptures could define the amount of lynx which have been recaptured (lynx 1 = 3 times, lynx 2 = 2 times, lynx 3 = 4 times --> 3 recaptures).

3. 20 recaptures could mean the total number of recaptures over all individuals after the first detection (lynx 1 = 3 times, lynx 2 = 2 times, lynx 3 = 4 times --> 9 recaptures).


Answer of Mr. Efford:
The number of 'recaptures' is the total number of detections minus the number of different animals detected (your 3).

Thanks a lot!!