Trendlines are shown for significant slopes and the shaded area represents 95% confidence intervals.
Black lines represent the overall linear relationship during the entire study period and dashed lines represent bird-specific regressions.
Lines are predicted logistic curves estimating the probability of torpor use with respect to evening fat mass.
Black line indicates overall linear relationship irrespective of period.
These data points were smoothed (thick colored line), and the slope of these points (thin colored line) was used to determine metabolic state. Horizontal lines represent entry (blue) and arousal …
Signs in parentheses denote the direction of the effect, or where there was no significant relationship this is denoted as ‘neither’.
Breeding | Migration | |
---|---|---|
Morning body mass | Low (2.77 ± 0.05 g) | High (3.73 ± 0.05 g) |
Fat content at torpor entry | Low, consistent (5.56% ± 0.79%) | High, variable (32.94% ± 0.77%) |
Torpor propensity | Evening fat content (-) | Evening fat content (+) and night length (+) |
Torpor entry time | Evening fat content (+) | Neither |
Torpor duration | Evening fat content (-) | Night length (+) |
Pre-torpor energy expenditure | Evening fat content (+) and night length (+) | Neither |
Overnight fat mass loss | Evening fat content (+) and night length (+) | Night length (+) |
Supplementary results tables.
(A) Estimated marginal means and slopes of body composition and food consumption variables, descriptions of the statistical models, and statistical comparisons within and among periods. (B) Absolute and relative increases in body mass, fat mass, and fat content during the fattening period. (C) Correlations between body mass gains and duration of the fattening period, with mean torpor duration in the fattening period and food consumption in the fattening period. (D) Estimated marginal means and slopes of torpor use variables, descriptions of the statistical models, and statistical comparisons within and among periods.
Instantaneous percent fat content over time (as % of night) throughout each summer, fattening, and migration period, as well as during the whole study period for non-fatteners.
Red lines represent normothermic nights and blue lines represent torpid nights. The average breeding threshold ±1 standard error is indicated by horizontal dashed black and greay lines, respectively.
Morning body mass (black points) following focal nights across the entire study period, starting at the date of capture.
These data points were smoothed (greay line), and the slope of these points was used to define breeding, fattening, and migration periods for each bird, which are shaded blue, yellow, and red, respectively. Non-fatteners are also included and shaded dark red. The first panel shows night length throughout the study period.