Table 1.
Alternative models, the number and values of their parameters, and the goodness of fit statistics (coefficient of determination, R 2 , and the Akaike information criterion, AICc) for each model
| Model type | Model | R2 | AICc | # of par. | "Surf" NDVI | Additional parameters |
|---|---|---|---|---|---|---|
| (i) | (1) Z = {Z| NDVI = "Surf"NDVI} | 0.056 | 942.7 | 1 | 0.599 | |
| Individual | (2) Zi = {Z|NDVI = ("Surf"NDVI)i} | 0.245 | 897.2 | 8 | 0.64; 0.62; 0.46; 0.62; 0.67; 0.51; 0.63; 0.55 | |
| Individual | (3) Zmi = a × Zi + b | 0.501 | 790.7 | 10 | Same as above | a = 0.58; b = 435.4 |
| (ii) | (4) Zm = a × Z + b | 0.462 | 796.5 | 3 | 0.239 | a = 0.66; b = 650 |
| (5) Zm = a × (exp(b × Z)) | 0.46 | 797.6 | 3 | 0.239 | a = 737.8; b = 0.00057 | |
| (6) Zm = a × Z2 + b × Z + c | 0.462 | 796.6 | 4 | 0.239 | a = -2.782×10-5; b = 0.70; | |
| c = 635.5 | ||||||
| (iii) | (7) Zm = a × (dNDVI) + b × Z + c | 0.48 | 789.66 | 4 | 0.239 | a = -0.44; b = 0.66; c = 650.6 |
| (8) Zm = a × (dNDVI+) + b × (dNDVI-) + c × Z + d | 0.49 | 786.46 | 5 | 0.236 | a = -0.71; b = 0.086; d = 0.64; | |
| e = 680.4 |
Z is the elevational location. "Surf"NDVI marks the parameterized target NDVI value the elephants will follow according to the hypothesis of "surfing the green wave". An underscore i marks an individual-based parameter set or location, Zm marks the resulting modified elevational location following a linear or non-linear surf model. A vertical bar marks a condition, i.e. {Z| NDVI = "Surf"NDVI} means Z where NDVI equals "Surf"NDVI.