part_of feeding on plant sugar diel periodicity of sugar feeding All measurements of the intensities of nectar feeding that have been made over periods of days revealed diel periodicities. IDOMAL:0002405 IDOMAL:0002405 The times at which species fed on nectar tended to coincide with those at which they displayed other activities, i.e. individual species were consistently diurnal, crepuscular or nocturnal. This alone suggests that an endogenous rhythm underlies the timing of sugar feeding. idomal_namespace temporal interval