Table 3 Outputs of models used to test whether dietary breadth (Shannon-Weaver diversity index) significantly correlated with NDVI and plant family relative abundances

Model	Species	Standard deviation of random effect	AIC	Variable	Df (explanatory variable, total)	β	se	t	p
Dietary breadth vs. NDVI	Black rhino	0.18	281.14	NDVI	1, 194.4	0.0068	0.0021	3.32	0.011**
	Grevy’s Zebra		196.28	NDVI	1, 153	1.29	0.45	2.878	0.004**
	Grevy’s Zebra		196.28	NDVI²	1, 153	−1.55	0.45	−3.445	<0.001***
Dietary breadth vs key diet items	Black rhino	0.034	84.81	Fabaceae (legumes)	1, 183.77	−4.09	0.41	−9.86	<0.001***
				Fabaceae (legumes)²	1, 206.01	−1.64	0.31	−5.32	<0.001***
				Poaceae (grasses)	1, 193.72	0.34	0.33	1.03	0.31
				Poaceae (grasses)²	1, 204.75	−0.87	0.29	−2.99	0.0031**
				Ebenaceae	1, 144.60	−4.95	0.38	−12.78	<0.001***
				Ebenaceae ²	1, 197.30	−1.46	0.29	−4.99	<0.001***
	Grevy’s zebra		150.89	Poaceae (grasses)	1, 153	2.02	0.39	5.19	<0.001***
	Grevy’s zebra		150.89	Poaceae (grasses)²	1, 153	−2.80	0.39	−7.19	<0.001***

All models have dietary breadth as the dependent variable. The results of two linear regression models for Grevy’s zebra and two linear mixed effect models for black rhino, using black rhino ID as a random effect, are presented. All predictors were included as second-order polynomial predictors, which were dropped if they were not significant. Variable = predictors in the model with a superscript 2 indicating predictors included as second-order polynomials, Df = degrees of freedom, β = regression coefficient, se = standard error, t = t-value, p = p-value with significance codes *** = p < 0.001, ** = 0.001 < p < 0.01, * = 0.01 < p < 0.05.

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