R package secr
The R package secr has most of the features of DENSITY and many more. The R environment offers great advantages for advanced users, including the ability to control details of optimization, batch processing etc. For those less confident in R there is an interface that runs in a web browser.
secr 5.2.1 is the current version, with recent changes listed here. A recent version of R is required (>= 3.5.0). Earlier versions are archived below.
Corrections, bug reports and suggestions are welcome. Please direct queries to the Google group secr or the DENSITY | secr forum at phidot.org. Bug reports may also be raised as issues on GitHub.
The main features of secr are described in the overview pdf (below). The package secrdesign provides tools for study design. secrlinear is an add-on to secr for animals in linear habitats such as river systems (vignette). ipsecr implements the 'simulation and inverse prediction' method for a subset of models from secr (vignette). openCR performs open-population analyses (vignette).
secr is available from CRAN - including Windows and Mac binaries - so you should not need to download from here. Just follow your usual route for installing packages from your R GUI (e.g., Packages | Install package(s) in Windows). See below for various pieces of documentation including an overview of secr and a pdf version of the help pages.
In Windows you can also install secr by saving the binary zip file (below) to a local folder and using the menu option "Packages | Install packages(s) from local zip files...". Then remember to load it! You will need several other packages that can be downloaded from CRAN (use Packages | Install package(s)... on the Windows GUI).
secr_5.2.1.zip 3840K
<< current Windows binary
secr_5.2.1.tar.gz 1125K
<< current source package
Distributed with package
secr-overview 5.2.1.pdf
160K << introduction
secr-datainput.pdf
103K
<< data formatting and input
Miscellaneous
secr-version4.pdf
75K
<< major changes 3 > 4
secr-manual 5.2.1.pdf
1024K
<< help pages secr 5.2.1
secr-tutorial.pdf
211K
secr-sound.pdf 104K
Other documentation previously visible here has been consolidated in
The SECR book (Efford 2025).
Last updated: 31 March 2025