Introducing the R-package ‘birdring’

We introduce the R-package ‘birdring’, which provides a collection of R-functions to help with the analysis of ring re-encounter data. At present, it contains functions to read EURING data into R, to draw maps for visualising recovery data, to re-code EURING code into interpretable names, and to calculate the loxodromic and orthodromic distances between two encounter locations. The package also allows spatially different re-encounter probabilities to be estimated using the division-coefficient method. A function to obtain the proportional overlap between prior and posterior distributions facilitates parameter estimability, which is often an issue in mark–recapture models. The package is a work-in-progress and we welcome additional contributions of functions for the analysis of ring re-encounter data.