Table 1 Sampling variables for the selection of foraging habitats
Category | Variables | Description |
|---|---|---|
Topographic factors | Slope degree (°) | Large quadrat: < 10° = 1, 10°‒20° = 2, 20°‒30° = 3, > 30° = 4 |
Slope aspect | Large quadrat: shady slope = 1 (‒67.5° to 67.5°), sunny slope = 2 (112.5°‒247.5°), semi-sunny slope = 3 (67.5°‒112.5°, 247.5°‒292.5°) | |
Slope position | Large quadrat: upper = 1, middle = 2, lower = 3 | |
Human disturbance factors | Distance to water (m) | Straight-line distance (m) between the center of a large quadrat and the nearest water (ditch, canal, brook, or pool) |
Distance to settlement (m) | Straight-line distance (m) between the center of a large quadrat and the nearest residence | |
Distance to road (m) | Straight-line distance (m) between the center of a large quadrat and a road | |
Distance to tillagers (m) | Straight-line distance (m) between the center of a large quadrat and the nearest farmer working at a site | |
Food factors | Types of food | Type of crop: corn, potato, radish, cabbage, rape, shallot, green manure, tobacco |
Food richness | If more than two kinds of crops were in a large quadrat: yes = 1, no = 0 | |
Crop remains (g/m2) | The crop remains (g/m2): the average of 5 small quadrats, measured by an electronic balance | |
Tillage methods | Whether the crop patch was plowed by machine: yes = 1, no = 0 |