Error(s) in re-building vignettes:
--- re-building ‘bison_example.Rmd’ using rmarkdown
** Processing: /data/gannet/ripley/R/packages/tests-devel/paleopop.Rcheck/vign_test/paleopop/vignettes/bison_example_files/figure-html/siberia_raster-1.png
672x480 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 23308 bytes
Input file size = 23410 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 19500
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 19500

Output IDAT size = 19500 bytes (3808 bytes decrease)
Output file size = 19578 bytes (3832 bytes = 16.37% decrease)

** Processing: /data/gannet/ripley/R/packages/tests-devel/paleopop.Rcheck/vign_test/paleopop/vignettes/bison_example_files/figure-html/siberia_raster-2.png
672x480 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 23802 bytes
Input file size = 23904 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 19715
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 19715

Output IDAT size = 19715 bytes (4087 bytes decrease)
Output file size = 19793 bytes (4111 bytes = 17.20% decrease)

** Processing: /data/gannet/ripley/R/packages/tests-devel/paleopop.Rcheck/vign_test/paleopop/vignettes/bison_example_files/figure-html/paleoregion-1.png
672x480 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 22113 bytes
Input file size = 22215 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 18967
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 18967

Output IDAT size = 18967 bytes (3146 bytes decrease)
Output file size = 19045 bytes (3170 bytes = 14.27% decrease)

** Processing: /data/gannet/ripley/R/packages/tests-devel/paleopop.Rcheck/vign_test/paleopop/vignettes/bison_example_files/figure-html/hs_raster-1.png
672x480 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 24616 bytes
Input file size = 24730 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 20200
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 20200

Output IDAT size = 20200 bytes (4416 bytes decrease)
Output file size = 20278 bytes (4452 bytes = 18.00% decrease)

** Processing: /data/gannet/ripley/R/packages/tests-devel/paleopop.Rcheck/vign_test/paleopop/vignettes/bison_example_files/figure-html/carrying capacity generator-1.png
672x480 pixels, 3x8 bits/pixel, RGB
Input IDAT size = 22059 bytes
Input file size = 22161 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 18391
  zc = 9  zm = 8  zs = 1  f = 0
  zc = 1  zm = 8  zs = 2  f = 0
  zc = 9  zm = 8  zs = 3  f = 0
  zc = 9  zm = 8  zs = 0  f = 5
  zc = 9  zm = 8  zs = 1  f = 5
  zc = 1  zm = 8  zs = 2  f = 5
  zc = 9  zm = 8  zs = 3  f = 5
                               
Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 18391

Output IDAT size = 18391 bytes (3668 bytes decrease)
Output file size = 18469 bytes (3692 bytes = 16.66% decrease)