Skip to main content

Table 3 Performance output of the track- and dive-based metrics using BRT in explaining and predicting nPEE at the scale of dives and days

From: Track and dive-based movement metrics do not predict the number of prey encountered by a marine predator

Model

RMSE

mRMSE

sdRMSE

Corr

RMSE

mRMSE

sdRMSE

Corr

Dive

Day

Descent rate

6.7 ± 1.8

0.72 ± 0.10

0.96 ± 0.05

0.35 ± 0.08

242.6 ± 125.4

0.36 ± 0.11

0.98 ± 0.16

0.38 ± 0.29

Ascent rate

6.4 ± 1.8

0.69 ± 0.11

0.91 ± 0.06

0.49 ± 0.07

245.0 ± 131.6

0.37 ± 0.11

0.98 ± 0.17

0.49 ± 0.19

Bottom duration

7.0 ± 1.8

0.75 ± 0.11

0.99 ± 0.03

0.22 ± 0.08

260.6 ± 127.7

0.39 ± 0.11

1.05 ± 0.13

0.16 ± 0.28

Surface duration

7.1 ± 1.7

0.76 ± 0.09

1.01 ± 0.02

0.10 ± 0.14

259.2 ± 115.7

0.39 ± 0.09

1.07 ± 0.08

0.10 ± 0.23

Efficiency

6.9 ± 1.6

0.75 ± 0.10

0.99 ± 0.04

0.22 ± 0.15

239.0 ± 100.6

0.37 ± 0.09

1.00 ± 0.15

0.35 ± 0.31

Sinuosity

6.8 ± 1.9

0.73 ± 0.10

0.97 ± 0.05

0.31 ± 0.12

256.6 ± 127.8

0.38 ± 0.10

1.04 ± 0.13

0.29 ± 0.28

Hunting time

6.6 ± 1.9

0.71 ± 0.10

0.94 ± 0.06

0.50 ± 0.07

258.7 ± 120.7

0.39 ± 0.10

1.06 ± 0.14

0.02 ± 0.45

Horizontal speed

7.2 ± 1.8

0.76 ± 0.10

1.00 ± 0.03

0.18 ± 0.10

245.7 ± 123.6

0.37 ± 0.11

0.96 ± 0.15

0.51 ± 0.23

Turning angle

7.3 ± 1.8

0.77 ± 0.10

1.01 ± 0.03

0.03 ± 0.04

262.4 ± 115.1

0.39 ± 0.09

1.04 ± 0.11

0.28 ± 0.19

FPT

7.1 ± 1.7

0.75 ± 0.10

0.99 ± 0.03

0.22 ± 0.09

231.8 ± 110.8

0.35 ± 0.10

0.91 ± 0.14

0.56 ± 0.22

Move persistence

7.3 ± 1.7

0.77 ± 0.11

1.01 ± 0.02

0.14 ± 0.10

250.5 ± 100.2

0.38 ± 0.09

1.00 ± 0.09

0.43 ± 0.26

Dive

5.6 ± 1.2

0.61 ± 0.09

0.81 ± 0.07

0.62 ± 0.10

174.1 ± 83.1

0.27 ± 0.09

0.73 ± 0.17

0.74 ± 0.13

Track

7.2 ± 1.7

0.76 ± 0.10

1.00 ± 0.03

0.22 ± 0.07

234.7 ± 90.9

0.36 ± 0.08

0.95 ± 0.13

0.49 ± 0.25

All

5.8 ± 1.3

0.61 ± 0.09

0.81 ± 0.06

0.62 ± 0.09

183.6 ± 76.6

0.28 ± 0.08

0.74 ± 0.14

0.74 ± 0.15

Descent rate

7.0 ± 1.9

0.75 ± 0.10

1.00 ± 0.04

0.22 ± 0.10

255.8 ± 133.3

0.38 ± 0.11

1.03 ± 0.16

0.24 ± 0.26

Ascent rate

7.0 ± 1.9

0.74 ± 0.10

0.99 ± 0.05

0.26 ± 0.11

265.8 ± 133.2

0.40 ± 0.10

1.07 ± 0.14

0.03 ± 0.25

Bottom duration

7.0 ± 1.9

0.75 ± 0.11

1.00 ± 0.03

0.21 ± 0.09

262.4 ± 127.2

0.39 ± 0.11

1.06 ± 0.13

0.06 ± 0.33

Efficiency

7.0 ± 1.7

0.76 ± 0.10

1.01 ± 0.03

0.14 ± 0.14

242.1 ± 111.9

0.37 ± 0.10

1.00 ± 0.16

0.30 ± 0.35

Hunting time

6.9 ± 1.7

0.74 ± 0.10

0.98 ± 0.03

0.26 ± 0.10

261.0 ± 127.2

0.39 ± 0.10

1.06 ± 0.12

0.14 ± 0.22

  1. The root-mean-square error (RMSE; mean ± sd), the mean-based normalized RMSE (mRMSE), the standard-deviation-based normalized RMSE (sdRMSE), and the correlation coefficient (Corr.) are computed between the observed values of nPEE for each seal and the predicted values by the model fitted without the focal individual (i.e., leave-one-individual-out cross-validation). The dive model includes all the dive-based metrics, the track model includes all the track-based metrics, and the all model includes all the metrics. Dive metrics are calculated from the high-resolution dive profiles (i.e., at 1 Hz; upper section) or from the low-resolution dive profiles (lower section), i.e., simplified to five segments using the broken stick method similar to data transmitted by CTD-SRDL loggers