Some plants rely on birds for Cross-pollination. Plants produce nectar to attract specific bird pollinators. Bird pollinators extract the nectar from inside the flower, and come in contact with the pollen assisting the plant with cross-pollination. But the Flowerpiercers have an upturned and hooked bill to pierce a flower at its base to obtain nectar from outside the flower, not coming in contact with the pollen and not assisting the plant with cross-pollination.