Elk Distributions Relative to Spring Normalized Difference Vegetation Index Values

Table 1

Observed (O) and expected (E) frequencies, proportion of AVHRR image area by category and date, and Chi-square values of San Antonio Mountain, New Mexico elk locations and concurrent Analysis Area (5,912 km²) AVHRR image NDVI values classified into nonphotosynthetically active surface (NPAS) and photosynthetically active surface (PAS) categories for 1999, 2000, and 2001.

Year	AVHRR Image Date Range	No. Elk Obs.	NPAS		NPAS Area	PAS-1		PAS-1 Area	PAS-2		PAS-2 Area	PAS-3		PAS-3 Area	𝜒^2	df	𝑃-value
			O	E		O	E		O	E		O	E
1999	26 Mar–8 Apr	93		0.4	0.004	13	30	0.32	70	55	0.59	10	8	0.09	14.244	3	.003
	9 Apr–22 Apr	124	1	2	0.01	25	39	0.32	84	69	0.56	14	14	0.11	8.622	3	.035
	23 Apr–6 May	127	2	6	0.05	35	39	0.31	76	73	0.57	14	10	0.08	5.232	3	.156
	7 May–20 May	47				11	12	0.25	28	29	0.63	8	5	0.11	1.705	2	.636
	21 May–3 Jun	126	4	5	0.04	79	64	0.51	43	54	0.43		3	0.02	8.651	3	.034
	4 Jun–17 Jun	40					0.4	0.01	2	20	0.50	38	20	0.49	33.492	2	<.001
2000	25 Mar–7 Apr	79		5	0.06	12	37	0.46	47	30	0.37	20	8	0.10	50.072	3	<.001
	8 Apr–21 Apr	66		1	0.02	8	26	0.39	32	32	0.49	26	7	0.10	68.745	3	<.001
	22 Apr–5 May	145				8	37	0.25	96	89	0.61	41	20	0.14	45.807	2	<.001
	6 May–19 May	112				6	21	0.18	52	60	0.54	54	31	0.28	28.529	2	<.001
	20 May–3 Jun	77				3	15	0.20	6	28	0.37	68	33	0.43	64.567	2	<.001
	4 Jun–16 Jun	121				2	32	0.27	9	39	0.33	110	49	0.41	125.681	2	<.001
2001	6 Apr–19 Apr	31		4	0.11	8	15	0.48	23	12	0.39		0.5	0.02	17.281	3	<.001
	20 Apr–3 May	117	9	8	0.07	29	52	0.44	79	56	0.48		1	0.01	21.082	3	<.001
	4 May–17 May	62		0.3	0.00	3	18	0.29	32	32	0.52	27	12	0.19	31.801	3	<.001
	18 May–31 May	119				1	31	0.26	61	56	0.47	57	32	0.27	50.185	2	<.001
	15 Jun–28 Jun	58					14	0.24	7	17	0.29	51	27	0.47	40.526	2	<.001