Fig. 2. Fractional absorption of ingested water (f_W) across the gut of Palestine sunbirds ranged from 0.33 to 1.02 (mean ± S.E.M., 0.59±0.04, N=35) and declined significantly and non-linearly with water intake rate (F_1,29=40.03, P<0.0001, r²=0.54). Palestine sunbirds may therefore avoid absorbing up to 64% of ingested water when feeding on dilute nectars. In sunbirds feeding on 584 mmol l^-1 sucrose solutions, f_W was not significantly different between 15°C (filled circles) and 30°C (unfilled circles; 0.44±0.02 vs 0.43±0.02, respectively; F_1,5=0.22, P=0.66).

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