Head-mounted accelerometry accurately detects prey capture in California sea lions

Cole, Mason R.; Zeligs, Jenifer A.; Skrovan, Stefani; McDonald, Birgitte I.

doi:10.1186/s40317-021-00267-7

Animal Biotelemetry

Table 1 Relationships between prey length or prey length grouping and characteristics of true-positive detections

From: Head-mounted accelerometry accurately detects prey capture in California sea lions

Sampling rate	Test	DF	Prey capture duration		Max. heave Jerk		Max. surge deceleration		Heave Jerk integral		Surge accel. integral
Sampling rate	Test	DF	p	R²	p	R²	p	R²	p	R²	p	R²
CALI
333 Hz	Lin. Reg	54	< 0.0001*	*0.254*	0.214	0.029	0.098	0.051	0.0003*	*0.221*	< 0.0001*	*0.346*
	T-test	53	< 0.0001*		0.419		0.334		0.008*		< 0.0001*
200 Hz	Lin. Reg	54	< 0.0003*	*0.226*	0.351	0.016	0.079	0.057	< 0.0001*	*0.271*	< 0.0001*	*0.399*
	T-test	53	< 0.0001*		0.648		0.294		0.002*		< 0.0001*
100 Hz	Lin. Reg	55	< 0.0001*	*0.284*	0.487	0.009	0.056	0.066	< 0.0001*	*0.269*	< 0.0001*	*0.435*
	T-test	54	< 0.0001*		0.772		0.253		0.003*		< 0.0001*
50 Hz	Lin. Reg	54	< 0.0001*	*0.357*	0.224	0.028	0.221	0.028	< 0.0001*	*0.28*	< 0.0001*	*0.482*
	T-test	53	< 0.0001*		0.660		0.348		0.004*		< 0.0001*
32 Hz	Lin. Reg	50	< 0.0001*	*0.314*	0.292	0.025	0.275	0.024	0.002*	*0.18*	0.0004*	*0.225*
	T-test	49	< 0.0001*		0.938		0.695		0.019*		0.012*
20 Hz	Lin. Reg	34	0.243	0.041	0.372	0.024	0.89	< 0.001	0.026*	*0.142*	0.027*	*0.14*
	T-test	33	0.108		0.609		0.756		0.016*		0.002*
16 Hz	Lin. Reg	25	0.157	0.082	0.416	0.028	0.667	0.008	0.005*	*0.285*	0.006*	*0.277*
	T-test	24	0.316		0.155		0.994		0.004*		0.013*
NEMO
333 Hz	Lin. Reg	41	0.098	0.067	0.841	0.001	0.151	0.051	0.084	0.073	0.111	0.062
	T-test	40	*0.018**		0.837		0.066		0.079		0.097
200 Hz	Lin. Reg	43	0.108	0.06	0.774	0.002	0.113	0.059	0.044*	*0.093*	0.078	0.072
	T-test	42	*0.036**		0.924		0.062		0.095		0.123
100 Hz	Lin. Reg	43	0.087	0.068	0.838	0.001	0.114	0.059	0.049*	*0.089*	0.049*	*0.089*
	T-test	42	*0.028**		0.949		0.079		0.125		0.086
50 Hz	Lin. Reg	38	0.234	0.038	0.387	0.02	0.2	0.044	0.165	0.051	0.244	0.037
	T-test(W)	37(26)	0.090		0.294		*0.039**		0.141		0.144
32 Hz	Lin. Reg	18	0.105	0.147	0.36	0.05	0.64	0.013	0.169	0.108	0.238	0.081
	T-test	17	*0.014**		0.905		0.312		0.208		0.166
20 Hz	Lin. Reg	17	0.619	0.016	0.528	0.025	0.06	0.205	0.697	0.009	0.791	0.005
	T-test (W)	16(10)	0.026*		0.151		0.192		0.069		0.196
16 Hz	Lin. Reg	7	0.386	0.127	0.127	0.343	0.782	0.014	0.364	0.139	0.936	0.001
	T-test	6	0.335		0.186		0.732		0.734		0.881

Lin. Reg. indicates simple linear regressions. T-test refers to 2-sample Student’s t-tests assuming equal variance, comparing among large and small prey length groupings. T-test(W) indicates that Welch’s t-tests were used when variance was unequal among large and small prey length grouping. Df numbers in parentheses are degrees of freedom in Welch’s t-tests. Df varies with sampling rate within individual because only data from true-positive detections were included in statistical analyses. T-test df = (n−2) and Lin. Reg. df = (n−1)
Bold, italicized font and the * symbol denotes either a significant relationship (Lin. Reg.) or a significant difference among prey length group (T-test or T-test(W))

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ISSN: 2050-3385

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