Table 5 Results from LMMs investigating how provisioning rates and dietary sources fed to nestlings varied across the three study sites.

From: Integrated behavioural and stable isotope data reveal altered diet linked to low breeding success in urban-dwelling blue tits (Cyanistes caeruleus)

Response variable

Explanatory variable

Estimate

Std. Error

df

t value

P value

(a) Visits per nestling (log)

  Intercept

1.35

0.18

16.7

7.41

<0.001

  Site

0.25

0.08

14.9

3.05

0.008

  Time of day

−0.12

0.02

169.9

−6.75

<0.001

(b) Visits per nest

  Intercept

28.34

3.43

16.6

8.27

<0.001

  Site

−3.29

1.52

15.0

−2.16

0.047

  Time of day

−2.12

0.31

169.7

−6.74

<0.001

(c) Mean volume of caterpillars (log)

  Intercept

5.23

0.30

14.8

17.57

<0.001

  Site

−0.33

0.14

14.9

−2.43

0.028

(d) Amount of caterpillars

  Intercept

24.59

2.43

16.4

10.11

<0.001

  Site

−6.51

1.08

15.0

−6.01

<0.001

  Time of day

−0.64

0.21

169.6

−3.07

0.003

(e) Amount of other arthropods (log)

  Intercept

1.16

0.38

25.6

3.08

<0.001

  Time of day

−0.20

0.08

46.7

−2.63

<0.011

(f) Amount of unidentified items

  Intercept

1.60

1.23

27.4

1.30

0.206

  Site

1.97

0.47

13.8

4.23

0.001

  Time of day

−0.74

0.28

46.1

−2.63

0.012

  1. In all models, site, time of day and date were included as fixed effects, and dropped if not significant via backward selection (only significant variables are shown). Nest-box (brood) was included as random factor. We indicate in brackets whether the response variable was log-transformed.
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