Photo of the Week – November 1, 2012

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On Wednesday, our staff was out enjoying some beautiful fall weather and harvesting the last of our prairie seeds for the season.  Walking along a gravel lane, we found a small snake basking in the sun.  I didn’t recognize it, so I stopped to photograph it in case it was a species we hadn’t seen in our prairies before.  Thanks to Mardell Jasnowski and Nelson Winkel for helping me get the photo.  (And for being patient while I shot it from many different angles…)

A juvenile eastern racer (Coluber constrictor) – The Nature Conservancy’s Platte River Prairies, Nebraska.  As always, you can click on the image to see a larger and sharper version of it.

Juvenile eastern racers look very different from the adults of that species.  Adult racers don’t have any patterned markings on their backs, and are a uniform blue or green color on top and yellow on the belly.  In fact, they’re often called green racers or blue racers because of that coloration (also yellowbelly racers).  When I saw this juvenile, I didn’t even think about the possibility it might be a racer.  I was running through the names of all the snake species I could think of with brown and black patterned backs, and none of them fit what I was seeing.

Eastern racers aren’t the only snake species in which the juvenile has a different, more camouflaged appearance than the adult (black rat snakes are another example).  It’s also a phenomenon seen in other kinds of animals, including white-tailed deer and red-winged blackbirds – among many others.  I guess a little extra camouflage when you’re young and inexperienced in the world is probably a good idea!

Thanks to Dan Fogell for writing his excellent field guide, which helped me identify this snake.

Can Aphids Photosynthesize?

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Well, no.  But recent research shows that at least some may be able to convert sunlight into energy in a process very similar to the way plants do it.

A study published in Nature magazine back in August looked at a species of aphid called Acyrthosiphon pisum, which changes color based on the air temperature around it.  At optimal temperatures, the aphid tends to be orange, but in cooler temperatures, the aphid is more often green.  Through a series of experiments, the scientists determined that – as in plants – the pigmentation of those aphids helped them generate energy, and that the green aphids made more of it than the orange ones.

Can aphids make their own energy?

As is usually the case, more research is needed to confirm exactly what’s going on, and to see if other aphid species have the same ability.  But these are pretty extraordinary results. The process of converting sunlight to energy is common in plants, of course, but insects and other animals don’t do that – or so we thought. 

What the aphids appear to be doing isn’t technically photosynthesis (no carbon dioxide is fixed and converted to organic compounds – I’m just telling you what I read…) but many of the essentials are there.  The scientists wonder if the ability helps the aphids survive when they don’t have quick access to food – such as when they’re traveling from one plant to another.

You can read a more complete description of the study here.