Lerp‐feeding in birds: A smorgasbord experiment

Abstract

AbstractLerps from three species of psyllids were presented to recently‐caught wild birds. A total of 187 birds of 29 species was tested, each for a 20 min period. In most trials some lerps were eaten. Lerps of Glycaspis fuscovena were favoured by 21 of 22 bird species which ate lerps in the trials. Almost all lerps of Creiis ?corniculata were left uneaten. The percentage consumption of lerps of Lasiopsylla striatus was intermediate. This ordering is consistent with biomass and concentration of soluble sugars, though it is the reverse of the order for protein content. There was significant variation between bird species in the number of lerps eaten, with the best performers being thornbills, Weebill, pardalotes. Rufous Whistler, and White‐eared, Brown‐headed and Fuscous Honeyeaters. In most cases, associated with the detachment of the covering lerp, the psyllid nymph sheltering underneath was eaten also. This varied substantially between bird species and the nymph itself was probably an unimportant object of foraging. Most bird species ate a higher proportion of large (>2 mm long) than of small (< 2 mm) lerps; this was so especially for birds with relatively broad bills.