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Table 1 Results of mixed models testing the effects of individual, breeding and environmental factors on provisioning parameters

From: Inter-individual variation in provisioning rate, prey size and number, and links to total prey biomass delivered to nestlings in the Collared Flycatcher (Ficedula albicollis)

Effect DFNum DFDen t P
Percentage of larvae among the preys
Vresidual = 0.046 (N = 152). Vnestbox = 0.002 (N = 91). Varea = 0.025 (N = 13)  
  Sex [M] 1 88.1 − 0.40 0.687
  Age [Y] 1 134.3 − 0.75 0.452
  Body condition 1 138.5 0.47 0.639
  Hatching date 1 85.6 − 0.71 0.479
  Brood size 1 89.9 − 0.05 0.957
  Ambient temperature 1 76.4 0.73 0.466
Feeding rate
Vresidual = 22.338 (N = 152). Vnestbox = 0.000 (N = 91). Varea = 3.688 (N = 13)  
  Sex [M] 1 137.2 2.24 0.027
  Age [Y] 1 138.0 − 2.11 0.036
  Body condition 1 142.1 0.39 0.693
  Hatching date 1 140.3 0.96 0.337
  Brood size 1 141.1 5.90  < 0.001
  Ambient temperature 1 140.9 − 0.12 0.905
  % Larvae among the preys 1 132.0 − 1.56 0.121
Mean prey number
Vresidual = 0.188 (N = 152). Vnestbox = 0.068 (N = 91). Varea = 0.039 (N = 13)  
  Sex [M] 1 82.7 − 0.58 0.563
  Age [Y] 1 124.0 − 1.11 0.267
  Body condition 1 132.4 − 1.23 0.220
  Hatching date 1 88.3 − 2.65 0.009
  Brood size 1 90.6 0.24 0.808
  Ambient temperature 1 80.2 1.88 0.064
  % Larvae among the preys 1 127.7 2.90 0.004
Mean prey size
Vresidual = 0.112 (N = 152). Vnestbox = 0.002 (N = 91). Varea = 0.011 (N = 13)  
  Sex [M] 1 90.4 0.63 0.529
  Age [Y] 1 137.3 1.92 0.056
  Body condition 1 142.7 1.38 0.168
  Hatching date 1 86.8 2.99 0.004
  Brood size 1 93.5 − 1.32 0.190
  Ambient temperature 1 84.0 − 1.55 0.123
  % Larvae among the preys 1 122.5 − 0.21 0.832
  1. The effect of sex is expressed as Males versus Females, and the effect of age as Yearling versus Older adults. Two-way interactions between sex and age, on the one hand, and the other fixed effects, on the other hand were not significant and removed from the final models. Significant fixed effects are reported in italics. Analyses were run on 152 individuals (85 females and 67 males) with complete information for all the explanatory variables