Pollination of Banksia ericifolia Smith: Birds, Mammals and Insects as Pollen Vectors

Abstract

In coastal heath, 12 km north of Sydney, Banksia ericifolia set fruit after cross-pollination but not after controlled self-pollination. Animals removed nectar and pollen from inflorescences during the day but not overnight. Introduced honeybees (Apis mellifera) and native birds (Meliphagidae, Zosteropidae) visited flowers frequently during the day, carried pollen on their body surfaces and were likely to transfer pollen between plants. Native bees, nocturnal moths and ants also visited flowers but were too infrequent, did not move between plants or foraged inappropriately to be important pollinators. No mammals were seen visiting flowers and the small mammals we caught carried no pollen. Exclusion experiments confirmed that pollination occurred during the day and not at night, but the experiments were insufficient to determine the relative importance of honeybees versus birds as pollinators. Only about 3% of the flowers of Banksia ericifolia developed follicles under natural conditions. Follicle production in this species was limited by resources and not by pollinators, since multiple cross- pollinations of flowers did not increase follicle production above the natural rate.