APPENDIX 1.

Video (click on image) of Aphonopelma chalcodes burrowing through excavation using its pedipalps.

Appendix1 

APPENDIX 2.

Video (click on image) of Pelinobius muticus burrowing through intrusion.

Appendix2 

APPENDIX 3.

Mann-Whitney (MS) and Kolmogorov-Smirnov (KS) test results (p values) from the comparison of the properties of all burrows produced by Hysterocrates gigas, Pelinobius muticus, and Aphonopelma chalcodes. Yellow highlighted p values are considered significant ( p < 0.05). The mean, median, standard deviation, and range of each significantly different property is provided for each species. Highlighted values (blue and green) indicate the greater of the two.

  MW KS   Hysterocrates gigas   Aphonopelma chalcodes
        Mean Median Std Dev Range   Mean Median Std Dev Range
Surface openings 1.000 1.000   1.0 1.0 0.0 1   1.0 1.0 0.0 1
Maximum depth 0.045 0.162   25.1 19.8 15.1 5.9 - 53.0   12.0 9.8 6.0 3.1 - 21.2
Total length 0.178 0.445   36.5 25.5 25.6 6.3 - 84.0   24.3 17.9 16.6 6.1 - 58.8
Maximum width 0.236 0.489   8.6 8.6 2.1 3.8 - 11.6   7.8 7.9 2.2 3.7 - 11.6
Minimum width 0.072 0.144   3.7 3.3 1.7 1.2 - 6.8   5.2 5.0 1.8 2.9 - 8.3
Mean width 0.191 0.162   5.9 5.9 1.3 3.5 - 8.4   6.6 6.6 1.4 3.4 - 7.9
Maximum height 0.347 0.375   7.1 7.4 1.4 4.2 - 8,7   6.3 6.7 1.6 2.4 - 8.2
Minimum height 0.540 0.489   3.2 3.1 1.1 1.4 - 5.3   3.2 2.5 2.1 1.2 - 8.2
Mean height 0.902 0.995   5.1 4.9 1.0 3.3 - 6.6   4.9 5.1 1.5 1.9 - 7.0
Average W/H ratio 0.835 0.489   1.2 1.1 0.2 1.0 - 1.7   1.2 1.2 0.4 0.5 - 1.8
Maximum circumference 0.022 0.012   25.0 24.8 4.7 13.0 - 31.0   19.3 22.3 7.6 2.7 - 25.4
Minimum circumference 0.307 0.759   12.7 11.8 5.2 4.0 - 21.0   10.2 9.9 4.6 1.8 - 17.6
Mean circumference 0.487 0.375   18.5 18.6 3.3 12.2 - 23.2   16.0 18.7 6.2 2.2 - 21.7
Maximum slope 0.002 0.003   89.0 90.0 3.2 80 - 90   57.2 55.0 24.7 25 - 90
Minimum slope 0.215 0.341   42.5 40.0 36.2 0 - 90   22.6 21.0 18.6 0 - 60
Mean slope 0.002 0.003   72.3 80.0 16.9 46 - 90   37.3 28.0 17.1 25 - 77
Complexity 0.006 0.038   3.8 4.0 1.1 2 - 4   2.4 2.0 0.5 2 - 3
Tortuosity 0.120 0.051   1.24 1.21 0.19 1.00 - 1.56   1.28 1.04 0.53 0.98 - 2.50
  MW

 

KS

 

  Hysterocrates gigas   Pelinobius muticus
    Mean Median Std Dev Range   Mean Median Std Dev Range
Surface openings 1.000 1.000   1.0 1.0 0.0 1   1.0 1.0 0.0 1
Maximum depth 0.068 0.047   25.1 19.8 15.1 5.9 - 53.0   36.7 36.0 6.9 27.0 - 48.5
Total length 0.056 0.012   36.5 25.5 25.6 6.3 - 84.0   56.9 56.5 12.2 42.0 - 73.0
Maximum width 0.005 0.001   8.6 8.6 2.1 3.8 - 11.6   4.8 4.7 0.8 4.1 - 6.5
Minimum width 0.050 0.149   3.7 3.3 1.7 1.2 - 6.8   2.4 2.4 0.4 1.8 - 3.2
Mean width 0.002 0.004   5.9 5.9 1.3 3.5 - 8.4   3.4 3.2 0.9 2.6 - 5.6
Maximum height 0.033 0.025   7.1 7.4 1.4 4.2 - 8,7   4.9 4.5 1.8 2.7 - 8.8
Minimum height 0.036 0.064   3.2 3.1 1.1 1.4 - 5.3   2.2 2.2 0.5 1.6 - 2.9
Mean height 0.005 0.004   5.1 4.9 1.0 3.3 - 6.6   3.4 2.9 1.0 2.2 - 5.4
Average W/H ratio 0.259 0.738   1.2 1.1 0.2 1.0 - 1.7   1.0 1.1 0.2 0.7 - 1.2
Maximum circumference 0.003 0.001   25.0 24.8 4.7 13.0 - 31.0   15.2 14.1 2.7 12.5 - 20.5
Minimum circumference 0.021 0.047   12.7 11.8 5.2 4.0 - 21.0   8.0 7.3 1.6 6.5 - 10.5
Mean circumference 0.001 0.001   18.5 18.6 3.3 12.2 - 23.2   11.0 10.5 2.4 8.3 - 16.5
Maximum slope 0.935 0.985   89.0 90.0 3.2 80 - 90   88.8 90.0 3.5 80 - 90
Minimum slope 0.032 0.012   42.5 40.0 36.2 0 - 90   5.0 0.0 7.6 0 - 20
Mean slope 0.117 0.149   72.3 80.0 16.9 46 - 90   59.2 57.5 10.3 48 - 80
Complexity 0.487 0.827   3.8 4.0 1.1 2 - 4   4.4 4.0 1.4 3 - 6
Tortuosity 0.168 0.305   1.24 1.21 0.19 1.00 - 1.56   1.44 1.46 0.33 1.07 - 2.06
  MW

 

KS

 

  Aphonopelma chalcodes   Pelinobius muticus
    Mean Median Std Dev Range   Mean Median Std Dev Range
Surface openings 1.000 1.000   1.0 1.0 0.0 1   1.0 1.0 0.0 1
Maximum depth 0.001 0.001   12.0 9.8 6.0 3.1 - 21.2   36.7 36.0 6.9 27.0 - 48.5
Total length 0.002 0.001   24.3 17.9 16.6 6.1 - 58.8   56.9 56.5 12.2 42.0 - 73.0
Maximum width 0.011 0.005   7.8 7.9 2.2 3.7 - 11.6   4.8 4.7 0.8 4.1 - 6.5
Minimum width 0.001 0.001   5.2 5.0 1.8 2.9 - 8.3   2.4 2.4 0.4 1.8 - 3.2
Mean width 0.001 0.001   6.6 6.6 1.4 3.4 - 7.9   3.4 3.2 0.9 2.6 - 5.6
Maximum height 0.083 0.034   6.3 6.7 1.6 2.4 - 8.2   4.9 4.5 1.8 2.7 - 8.8
Minimum height 0.335 0.638   3.2 2.5 2.1 1.2 - 8.2   2.2 2.2 0.5 1.6 - 2.9
Mean height 0.048 0.029   4.9 5.1 1.5 1.9 - 7.0   3.4 2.9 1.0 2.2 - 5.4
Average W/H ratio 0.331 0.279   1.2 1.2 0.4 0.5 - 1.8   1.0 1.1 0.2 0.7 - 1.2
Maximum circumference 0.075 0.024   19.3 22.3 7.6 2.7 - 25.4   15.2 14.1 2.7 12.5 - 20.5
Minimum circumference 0.135 0.279   10.2 9.9 4.6 1.8 - 17.6   8.0 7.3 1.6 6.5 - 10.5
Mean circumference 0.043 0.005   16.0 18.7 6.2 2.2 - 21.7   11.0 10.5 2.4 8.3 - 16.5
Maximum slope 0.006 0.005   57.2 55.0 24.7 25 - 90   88.8 90.0 3.5 80 - 90
Minimum slope 0.025 0.029   22.6 21.0 18.6 0 - 60   5.0 0.0 7.6 0 - 20
Mean slope 0.009 0.005   37.3 28.0 17.1 25 - 77   59.2 57.5 10.3 48 - 80
Complexity 0.003 0.041   2.4 2.0 0.5 2 - 3   4.4 4.0 1.4 3 - 6
Tortuosity 0.048 0.005   1.28 1.04 0.53 0.98 - 2.50   1.44 1.46 0.33 1.07 - 2.06

APPENDIX 4.

Quantitative measurements of the burrows of comparative animals. All measurements in cm or degrees (slope only); W/H ratio, complexity, and tortuosity are unitless. GI# = Gorgyrella inermis burrow cast identification number; PI# = Pandinus imperator burrow cast identification number; MM# = Mabuya multifasciata burrow cast identification number; AT# = Ambystoma tigrinum burrow cast identification number.

Gorgyrella inermis
ID Openings Depth Length Max Width Min Width Mean Width Max Height Min Height Mean Height W/H Ratio Max Circ Min Circ Mean Circ Max Slope Min Slope Mean Slope Complexity Tortuosity
GI1 1 7.2 7.8 2.1 1.6 1.9 1.9 1.5 1.7 1.1 6.3 5.7 6 85 85 85 2 1.1
GI2 1 7.2 7.9 2.4 1.8 2.1 2.4 1.7 2.1 1 7.6 5.8 7 85 85 85 2 1.1
GI3 1 9.8 10 2.5 1.8 2.2 2.5 1.7 2.1 1 7.8 5.1 6.7 85 85 85 2 1
GI4 1 13.4 13.6 3.2 1.9 2.9 2.9 2.2 2.7 1.1 9.8 6.1 9 85 85 85 2 1
GI5 1 14.2 14.6 2.3 1.8 2.1 1.7 2.4 2.1 1 7.5 5.7 7.1 90 85 87.5 2 1.1
GI6 1 9.4 9.6 3 2.6 2.9 2.8 2.2 2.5 1.2 9.3 7.4 8.6 88 88 88 2 1
GI7 1 16.3 18.4 2.4 1.9 2.1 2.7 1.7 2.1 1 7.9 5.4 6.6 90 78 84 3 1.4
Pandinus imperator
ID Openings Depth Length Max Width Min Width Mean Width Max Height Min Height Mean Height W/H Ratio Max Circ Min Circ Mean Circ Max Slope Min Slope Mean Slope Complexity Tortuosity
PI1 1 6.5 28 7.6 6 6.7 4.4 2.9 3.7 1.8 23.5 17.5 19.3 20 15 17 3 1
PI2 1 5 18 6.3 3.6 5.6 3.6 2.2 2.8 2 18 12 15.1 20 0 13 3 1.1
PI3 1 13 34 11.6 3.9 8.2 4.2 1.9 2.9 2.8 28 10 19.7 50 0 19.3 3 1.1
PI4 1 6 29 7.1 3.8 6.3 3.8 1.7 2.9 2.2 19.5 12 17 20 0 6.7 3 1
PI5 1 7 19.5 6.3 4.8 5.8 2.7 1.8 2.5 2.3 16 13 15.2 20 0 13 2 1
PI6 1 12.5 34 12 7.4 9.6 7.1 3 3.9 2.5 28.5 20.5 24.8 30 0 14 3 1.7
PI7 1 16 34 11.3 5.5 8.7 5.4 3.9 4.5 1.9 27.1 12.2 21.5 30 0 24 3 1.1
PI8 1 14 29 6.4 4.3 5.5 3.4 2.1 2.7 2 16 11 14.1 50 0 21 3 1.1
PI9 1 15 32 8.3 4.2 6.5 5.9 2 4.5 1.4 22.5 12.5 19 30 0 18 3 1.5
Mabuya multifasciata
ID Openings Depth Length Max Width Min Width Mean Width Max Height Min Height Mean Height W/H Ratio Max Circ Min Circ Mean Circ Max Slope Min Slope Mean Slope Complexity Tortuosity
MM1 1 2.3 6.5 2.2 1.9 2 2 1.3 1.6 1.3 7.4 6.8 7.2 51 4 28 2 1.0
MM2 1 5.4 28.7 5.3 2.2 4 3 1.9 2.5 1.6 13.9 7 11.9 32 6 19 2 1.2
MM3 1 5.3 19.6 5.1 1.9 3.3 2.6 1.5 2.1 1.6 12.5 6.5 9.3 42 5 24 3 1.1
MM4 1 2.8 11 3.5 2.4 2.8 2.7 1.6 2 1.4 9.7 7.2 8.4 55 28 42 2 1.2
MM5 1 4.8 11 2.5 2.1 2.3 5.6 2.4 3.6 0.7 14.2 8.1 10.8 30 7 19 2 1.2
MM6 1 5 14.5 2.6 1.9 2.3 2.4 1.4 1.8 1.3 8.2 6.1 6.9 45 10 28 2 1.2
MM7 1 3.8 10.8 4.5 2.2 3.1 2.9 1.4 2.4 1.3 11.8 5.5 8.5 48 3 26 2 1.0
MM8 1 9.4 11.6 4.3 2 2.8 3.4 1.5 2.2 1.2 14.2 6.4 9.6 62 35 49 2 1.2
Ambystoma tigrinum
ID Openings Depth Length Max Width Min Width Mean Width Max Height Min Height Mean Height W/H Ratio Max Circ Min Circ Mean Circ Max Slope Min Slope Mean Slope Complexity Tortuosity
AT1 1 5.8 9.8 3.3 1.2 2.1 2.2 1.1 1.5 1.4 13 4.5 9.8 35 35 35 2 1.5
AT2 1 9.3 19.5 5 1.6 3.5 3.1 1.6 2.4 1.5 11.3 6.1 9.3 67 67 67 2 1.3
AT3 1 4 11.3 4.1 1.9 3.2 2.8 1.6 2.1 1.5 11.1 6.1 8.3 31 31 31 2 1.3
AT4 1 7.5 9 2.1 0.9 1.7 1.7 1.1 1.5 1.1 7.2 4.3 6 64 64 64 2 1.2
AT5 1 9.8 13 4.5 2.9 3.8 3.4 2.6 2.8 1.4 11.6 9.3 10.5 53 53 53 2 1.1
AT6 1 12.4 15.5 3.5 2.4 2.9 2.5 1.3 1.9 1.5 9 6.4 7.6 65 65 65 2 1
AT7 1 8.7 12.5 3.6 2.3 3 3.2 1.5 2.2 1.4 10.6 6.9 8.2 62 62 62 2 1.3
AT8 1 5.2 10 3 2.1 2.7 2 1.5 1.8 1.5 8.4 6.2 7.3 40 40 40 2 1.6
AT9 1 4.2 11.3 2.5 2 2.2 2.6 1.6 2 1.1 8.6 5.8 7.5 40 40 40 2 1.3