Announcing secr 5.3

[murray.efford]

secr 5.3.0 is now on CRAN. There is new functionality for modelling spatial variation in detection parameters lambda0 and sigma (see secr-detectionxy.pdf) and for relative density models. Simulation of Ornstein-Uhlenbeck movement and detection with functions simOU() and simOU.capthist() has been moved from package secrdesign.