Software for spatially explicit capture-recapture
LATEST: Short course on SECR Whitehorse, Yukon, 7-9 August. secr 2.3.2 released
Use the Windows application DENSITY 4.4 or the R package secr to estimate the density of animal populations from capture-recapture data collected using an array of 'detectors'. Detectors may be live-capture traps, with animals uniquely marked; they also may be sticky traps or snags that passively sample hair, from which individuals are distinguished by their DNA microsatellites, microphones, or cameras that take photographs from which individuals are recognized by their natural marks. In secr it is possible also to analyse data obtained by searching areas for identifiable cues such as faeces. The software includes tools for plotting and simulating spatial capture-recapture data, creating geometric arrays of detectors, etc.
Spatially explicit capture-recapture (SECR) uses the locations where each animal is detected to fit a spatial model of the detection process, and hence to obtain estimates of population density unbiased by edge effects and incomplete detection. Inverse prediction (IP SECR) and maximum likelihood (ML SECR) are alternative methods for fitting the spatial detection model (Efford 2004, Borchers & Efford 2008). See What is SECR? for more.
DENSITY runs under Windows XP and Windows 7, and other recent versions of Windows. Screen size should be set to at least 1024 x 768 pixels. Check the file readme4.txt for more information. An online help file is included. The software is free and no warranty is provided. DENSITY 4.4.6 differs only slightly from previous releases. Specific changes and new features since 4.2 are described here.
The R package secr
covers a wider range of analyses than DENSITY.
secr 2.3.2 is available here and on CRAN. This release includes a function to generate realistic random landscapes. Click here for a full list of new changes.
Please also note the DENSITY | secr forum at phidot.org. Read forum FAQ.
Download DENSITY 4.4
Last Updated: 19 May 2012