Examples of behaviours with characteristic signals from dynamic acceleration and static acceleration.

<p>Characteristic signals from dynamic acceleration (A–D) and static acceleration (E–F) are shown. In all panels, acceleration in the surge (X) axis is shown with a continuous grey line, in the sway (Y) axis with a dashed line and in the heave (Z) axis with a continuous black line. Fly and forage (A, B) are especially characterized by high-amplitudes of all dynamic acceleration components, but the frequency of the signals is higher for fly than it is for forage (especially in the Z direction, see dpsZ in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone-0037997-g004" target="_blank">Figure 4</a>). Many of the accelerometer signals for foraging are characterized by the alternation between relatively smooth lateral movement (changes in acceleration predominantly in the surge axis) and short bursts of high frequency changes in acceleration in all three axes (e.g. catching prey, at 2.2 s panel B, see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone.0037997.s007" target="_blank">Video S1</a>). The changes in dynamic acceleration for body care (C) are much smaller than for fly and forage, but still considerably higher than for stand and sit (D, see also odbaX and odba in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone-0037997-g004" target="_blank">Figure 4</a>). The static acceleration can be used to distinguish sit (E) and stand (F) due to differences in body posture (see pitchX in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone-0037997-g004" target="_blank">Figure 4</a>).</p

Decision tree and confusion matrix for models S3 and SA3.

<p>For model S3 (A) and model SA3 (B), the number of observations correctly classified per behaviour is shown in bold. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone-0037997-t002" target="_blank">Table 2</a> for a description of the predictor variables. Out of the 702 observations, there were no speed measurements in 7 cases, hence the sample size of 695 for model S3.</p

Diurnal and nocturnal time budget of one oystercatcher during July 2009, using model SA8 to classify behaviours.

<p>Diurnal (top) and nocturnal (bottom) time budgets for one oystercatcher (logger 169, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone.0037997.s004" target="_blank">Table S1</a>) during July 2009, using model SA8 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone-0037997-g004" target="_blank">Figure 4</a>) to classify behaviours. The locations of each behaviour (fly, forage, body care, stand and sit) are presented on the map; the colours of the icons on the map correspond to those in the time budget bar graphs.</p

Different behaviours and sub-behaviours visually observed during the study and linked to GPS and accelerometer measurements.

<p>Different behaviours and sub-behaviours visually observed during the study and linked to GPS and accelerometer measurements.</p

Decision tree and confusion matrix for model SA8.

<p>The number of observations correctly classified per behaviour is shown in bold. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone-0037997-t002" target="_blank">Table 2</a> for a description of the predictor variables.</p

Predictive parameters used in this study, derived from the GPS (speed) and the accelerometer sensors.

<p>Predictive parameters used in this study, derived from the GPS (speed) and the accelerometer sensors.</p

The study area on the island of Schiermonnikoog, the Netherlands (53.29°N, 06.10°E) at different spatial scales.

<p>The points represent GPS fixes of three oystercatchers (green – tag 166, red – tag 167, blue – tag 169; <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037997#pone.0037997.s004" target="_blank">Table S1</a>) from 1 July 2009 to 31 July 2009, with consecutive points connected by lines. The black circles are the nests of these birds. The locations of the observation towers are indicated by a square and the base station by a triangle. Black lines represents creeks, dark grey lines represent urban infrastructure.</p