Friday, May 16, 2008

Pollinators - Reptiles

The island of Mauritius is famous, or perhaps infamous, for having been the habitat of the Dodo bird. The dodo was a wonderful seed distributor but was probably not a pollinator. Instead that task fell to other indigenous birds like the Olive white-eye. Unfortunately, the Olive white-eye has more than just its native land in common with the dodo. The Olive white-eye is critically endangered and scientists fear only 150 nesting pairs may be left on Mauritius. The Olive white-eye was the key pollinator of the Trochetia, a plant producing pink, orange or white flowers. The Trochetia is also endangered due to invasive plant species and feral populations of monkeys and rats, but the Trochetia's fate could be more hopeful than that of the Olive white-eye.

Also living on the Island of Mauritius is the Blue-tailed Day Gecko. This tiny lizard is endemic to the island. A confirmed insectivore, the gecko found its food sources of insects becoming increasingly scarce and so began feeding on nectar. The Blue-tailed day gecko has been gradually taking over the duties of the Olive white-eye in becoming the Trochetia's main pollinator. In return, the Trochetia flowers have even begun to produce colored nectar, in shades of yellow and red; instead of the clear nectar other plants produce. It seems color is more important in attracting the little lizard than scent is. As the gecko dips in to the deep bell-shaped flowers, pollen falls across its throat and lips, adhering to the gecko's scales. While visiting another flower, the gecko brushes this pollen off on the flowers stigma, helping the Trochetia keep its fragile hold on the island.

Scientists are discovering that lizards are frequently the main pollinators in island communities. The Lilford's Wall Lizard is responsible for the pollination of over 20 plant species found off the coast of Spain. Lizards make very capable pollinators as they can carry a lot of pollen for long distances. Their inability to get off the island also makes them a more reliable resource than the birds.

Photo courtesy of Dennis Hansen.

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