parameter estimate 95% CI z p
fixed effects
intercept -0.131 -0.226, -0.035 -2.677 0.007
sex -0.036 -0.100, 0.029 -1.086 0.277
average age 0.000 -0.007, 0.007 0.093 0.926
delta age 0.001 -0.002, 0.003 0.514 0.607
sex:delta age -0.004 -0.008, -0.001 -2.399 0.016
random effects
bird identity 0.095 0.074, 0.121
position identity 2.739 2.714, 2.764
observation 1.263 1.26, 1.265