07 September 2011

Convergent Evolution

I thought I was looking at a tiny hummingbird with his long proboscis in our red geranium. (Look where yellow and orange meet about a third of the way down the photo.) I've seen hummingbirds as small as this in Trinidad's Rain Forest. The smallest of the hummingbirds, the Bee Hummingbird, lives there and measures just 5cm. But my neighbor's daughter told me that Italy has no hummingbirds and that instead it was a hummingbird hawk-moth. Who knew there was such a thing?

(image from Wikipedia)

Wikipedia said that the Hummingbird Hawk-moths that are loving my plants are a good example of convergent evolution. Right on my balcony! Ever a sucker for new facts, I skipped to the info about convergent evolution and found that it "describes the acquisition of the same biological trait in unrelated lineages." They cited the example of an owl and a cat which are "distantly related predators that share keen, night-time binocular vision and targetable ears to help their night time hunting."

(both images from Wikipedia)

But back to the Hummingbird Hawk-moths and the hummingbirds. My tiny visitor  is distinguished among moths for his rapid, sustained flying ability. In fact he is one of the fastest flying insects clocking in at 50km/h or 30m/h. He and his species hover in midair while they feed on nectar from flowers. Like hummingbirds, they are specialized nectarivores. Imagine! 

Anyway, their hovering capability has evolved only three times in nectar feeders: in hummingbirds, certain bats and hawk moths (family: sphingidae). The hummingbird hawk-moth's hovering is similar to, but distinct from, that of hummingbirds. Both have long and mostly straight bills for their specialized nectar feeding and drink it with their trough-like tongues.

It seems the plants that are pollinated by hummingbirds or hummingbird hawk-moths produce flowers in shades of red, orange and bright pink. My geranium is an almost neon orangey-red so that's evidently why I'm seeing so many of these hawk-moths. It's okay with me, nature is an awesome teacher!


  1. I had no idea. I understood Convergent Evolution as it applied to creatures in and of the sea - how the same niche has been filled at different times by completely different creatures that all come to look much alike. But moths? Cool. Very, very, cool.

  2. Lou, I agree. You gotta love Wikipedia!

  3. Fascinating! I had no idea -- either than Italy had no hummingbirds or that there were Hummingbird Hawk Moths to take up the slack. Your pictures are beautiful and I learned something new today. Thank you!

  4. Apparently we have a similar moth here in Minnesota, although we also have hummingbirds. My hubby saw one several times one summer while I was working, and we haven't seen it since. Next summer I'll plant something that's red-orange and see what happens!

  5. Kathy, Me too, and that makes it a good day.

    Nancy, There are different species in the US than here but hawk-moths none-the-less. If you google hummingbirds there's all kinds of suggestions about what to plant to attract hummingbirds, or in my case hummingbird hawk-moths. It would be great for the grands.

  6. I have only seen them in New Hampshire. Aren't they fascinating??


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