Parameter | β ± SE | t | P | Χ 2* | P* |
---|---|---|---|---|---|
δ13C | |||||
 Intercept | −23.42 ± 0.49 | 47.70 | <0.001 |  |  |
 Speciesa | 0.34 ± 0.43 | 0.78 | 0.433 | 0.71 | 0.39 |
 Anthropogenic steppeb | 0.62 ± 0.24 | 2.64 | 0.008 |  |  |
 Agricultural fieldb | 0.71 ± 0.29 | 2.43 | 0.015 | 7.92 c | 0.019 c |
δ15N | |||||
 Intercept | 8.58 ± 0.83 | 10.25 | <0.001 |  |  |
 Speciesa | −1.60 ± 0.36 | 4.45 | <0.001 | 21.16 | <0.001 |
 Anthropogenic steppeb | 0.05 ± 0.20 | 0.26 | 0.796 |  |  |
 Agricultural fieldb | 0.13 ± 0.24 | 0.54 | 0.585 | 0.31 | 0.85 |