Effects of nicotine on the digestive performance of nectar-feeding birds reflect their relative tolerance to this alkaloid.

摘要: The paradox of secondary metabolites, toxic defence compounds produced by plants, in nectar and fruits is well known. Deterrence feeding nectarivorous frugivorous birds better understood than the effect these chemicals on digestive performance birds. Digestive parameters such as transit time sugar assimilation are important assessing nutrient utilization deterrence may be related to post-ingestive effects involving parameters. Nectar many contain mainly sugars water, avian consumers compensate for low content their diet increasing food intake: this also increase intake metabolites. We investigated how alkaloid nicotine, naturally present Nicotiana species, influences compensatory nectar-feeding High nicotine concentration negatively affected apparent efficiency white-bellied sunbirds Cinnyris talatala Cape white-eyes Zosterops virens; but slowed gut only latter species. In contrast, dark-capped bulbuls Pycnonotus tricolor was unaffected up a 50μM. Bulbuls primarily frugivorous; hence, they more exposed metabolites possibly white-eyes. Because richer toxins, have evolved efficient detoxification strategies those specialist