Wednesday, March 30, 2016

It Isn’t Pretty, It’s Ecology

Sometimes we like to think that the natural world is all full of nice animals and plants just waiting to be explored by day hikers like me. We all know this is not true, but it is a nice feeling. On the other hand, certainly in the world of bees and flowers, the world must be pretty nice, right?

It would be nice if pollinators and flowers just helped one another out: the pollinators get pollen and nectar as food, while the flowers get to cross-breed and enhance their genetic diversity. But the reality can be pretty messy. Pollinators do not just need resources, but they need to be the first pollinators to get those resources. The first pollinator to visit the flower gets the nectar, which may or may not be replenished by the time the second pollinator arrives. With this kind of competition, some pollinators may not even wait for the flowers to open. They might chew a hole through the petals to get at the nectar in an unopened flower. In so doing, they do not pollinate the flower, since they do not brush up against either the stamens (which produce pollen) or the stigmas (which receive it). These insects are just like the Sooners in Oklahoma history, who sneaked into Oklahoma Territory to stake out their land claims before the official opening shot.

Not only that, but flowers are specialized for certain pollinators. Wisteria flowers, for example, have petals in the form of a banner, wings, and keel. The pollen and nectar are down inside the keel. The keel is closed up, and only a fairly heavy pollinator, such as a bumblebee, can open it. Honeybees cannot easily open them.

When I walked home from work one recent afternoon, I saw honeybees flying around newly opened Wisteria flowers. Usually I see bumblebees, but this does not seem to have been a good year for them. But why were the honeybees there? It turned out that the honeybees were chewing holes in the side of the flower to drink the nectar down inside, as in these photos.

Mother Nature can be one tough mama. Snakes eat cute little nestlings, parasites are everywhere, and even when bees visit flowers there is a Darwinian struggle for existence going on. Of course, I feel a sense of awe when I behold the overall structure of nature.

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