Table 2.
Model selection for types I, II, and III functional responses of flamingo feeding on Chironomid larvae: (A) for the experimental range of densities (from 5 to 600 Chironomid larvae per tray) and (B) only for the natural range of densities (from 5 to 60 Chironomid larvae per tray)
| Holling model type | Intake rate | K | Deviance | AICc | Δ AICc | AICc weights (%) | Parameter estimates |
|---|---|---|---|---|---|---|---|
| (A) | |||||||
| Type II |  |
3 | 8.35 | −10.21 | 0 | 70.69 | a = 0.0012 (±0.00023) P < 0.001 h = −0.082 (±0.00014) P < 0.001 |
| Full Type III |  |
4 | 8.32 | −7.79 | 2.42 | 21.08 | a = 0.0012 (±0.00022) P < 0.001 h = −0.80 (±0.26) P < 0.001 |
| Partial Type III | a × Ds (s = 1.60) | 3 | 6.20 | −5.90 | 4.31 | 8.19 | a = 0.000064 (±0.000004006) P < 0.001 |
| Type I through zero | a × D | 2 | −0.85 | 5.95 | 16.16 | 0.022 | |
| Type I | a × D + β | 3 | 0.030 | 6.44 | 16.65 | 0.017 | |
| (B) | |||||||
| Type II |  |
3 | 39.43 | −71.65 | 0 | 42.23 | a = 0.0064 (±0.0052) P = 0.23 h = 9.59 (±4.76) P = 0.056 |
| Type I through zero | a × D | 2 | 37.34 | −70.11 | 1.54 | 19.55 | a = 0.0019 (±0.00038) P < 0.001 |
| Type I | a × D + β | 3 | 38.52 | −69.85 | 1.80 | 17.17 | a = 0.0011 (±0.00064) P = 0.099 |
| Full Type III |
(s
= 3.2)
|
4 | 39.91 | −69.71 | 1.94 | 16.01 | a = 0.0062 (±0.0051) P = 0.23 h = 9.65 (±4.72) P = 0.052 |
| Partial Type III | a × Ds | 3 | 36.91 | −67.40 | 4.25 | 5.04 | |
For the type III functional response, both the entire shape (‘Full Type III’) and the first exponential part of a sigmoid (‘Partial Type III’) were tested. Only results with the value of s (‘shape parameter’) giving the best AICc are presented. The best model is indicated in bold. K corresponds to the number of parameters, IR designs intake rate, D is the food density, s the ‘shape parameter’, a the attack rate (in number of Chironomid larvae/second), and h the handling time (in sec). β is the intercept of a type I not forced through zero. Parameter estimation (±SE) is given for the best model(s) only.