To cite package 'secr' in publications use:

Efford M (2020). secr: Spatially explicit capture-recapture models. R package version 4.3.0, https://CRAN.R-project.org/package=secr.

Corresponding BibTeX entry:

  @Manual{,
    title = {secr: Spatially explicit capture-recapture models},
    author = {Murray Efford},
    year = {2020},
    note = {R package version 4.3.0},
    url = {https://CRAN.R-project.org/package=secr},
  }