Tricky Sex Technique

A South African plant has developed a novel way to encourage cross-pollination by birds.

Babiana ringens, more commonly known as the rat's tail, grows a specialized perch to encourage the foraging malachite sunbird (Nectarinia famosa) to adopt the best position for pollen contact while drinking the nectar from its ground-level flowers.

Spencer Barrett at the University of Toronto and colleagues found the presence of this perch increases the mating success of the rat's tail.

When a sunbird lands on the perch, it inserts its curved beak into the flowers from above. In this position, its breast is brushed with pollen from the plant's sexual organs that can then be transferred to other plants.

In the image above, the perch is indicated with an arrow (A). Note the ground-based flowers (B). A bird adapts its feeding strategy when the perch is absent (C).

The researchers removed the perches from some plants and noticed that the sunbirds preferred those plants that remained intact. Male sunbirds displayed a particular preference for plants with perches, and the team argue that this could be associated with their longer tail feathers, which make it harder to take flight from the ground.

The finding is detailed in the May 5 issue of the journal Nature.

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-- LiveScience Staff

Image credit: S.C.H. Barrett, C. Ewart-Smith