Lizard Pollinators

Apr 24, 2007 07:10 GMT  ·  By

We know that flowers are pollinated by bees, butterflies, hummingbirds, sunbirds, white-eye birds, pollen-eating bats. And pollinators use to fly. But a pollinating lizard?

Yes, they do exist, and on the island of Mauritius (in the Indian Ocean), the blue-tailed day gecko is the key factor in the survival of the native threatened Trochetia flower. In fact, it's the combination between gecko and Pandanus, a palmlike shrub, that offers the lizard a safe haven from predators. This gecko is unusual not only by being diurnal, having one of the brightest green colors seen in nature and indulging itself with nectar.

Trochetia flowers are also visited by insects and the olive white-eye bird, but the bugs transport little pollen from one blossom to another, and the bird is nearly extinct, thus the 5 inch (13 cm) lizard remains the main pollinator.

"An animal may visit flowers often, eating pollen or nectar, but not provide a good pollination service. Our study is one of the few to provide evidence that lizards can indeed be efficient pollinators." said study leader Dennis Hansen of the University of Zurich in Switzerland.

While feeding with nectar, the gecko transfers pollen from one blossom to another.

But on open space, the lizards are exposed to the Mauritian kestrel, a small falcon that eats insects and lizards, that's why close impenetrable thickets of Pandanus plants protect the lizards. Trochetia flowers living close to Pandanus patches could bear fruit and reproduce, while those growing farther than Pandanus rarely succeeded.

Out of over 4,300 known lizard species, just 71 are known to be nectar-eating pollinators. "95 % of the flower-visiting lizard species are from islands," said Jens Olesen, of the University of Aarhus in Denmark.

"Lizards are available and other pollinators are not. Bird and insect faunas are usually [smaller] on islands, whereas lizards may be more abundant than on the mainland." said Joan Roughgarden, an ecologist at Stanford University in California.

There are island plants with special adaptations for attracting their lizard pollinators, like yellow or red nectar in Trochetia flowers. (almost all the other species produce clear nectar). Another endangered Mauritian plant seems to employ geckos both for pollination and seed dispersal.

"Similar chains of positive interactions involving cover-providing plants and pollinating lizards may be widespread in island communities," he noted.

Photo Gallery (2 Images)

Blue-tailed day gecko on a Trochetia flower
Blue-tailed day gecko on a Trochetia flower
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