To cite package 'secr' in publications use:

Efford, M. G. (2017). secr: Spatially explicit capture-recapture models. R package version 3.1.3. https://CRAN.R-project.org/package=secr

Corresponding BibTeX entry:

  @Manual{,
    title = {secr: Spatially explicit capture-recapture models},
    author = {Murray Efford},
    year = {2017},
    note = {R package version 3.1.3},
    url = {https://CRAN.R-project.org/package=secr},
  }