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Posts tagged “Pigments

Common Gartersnake Pigments

12-8-10      Common Gartersnake

The Common Gartersnake (Thamnophis sirtalis) is New England’s most common and widespread snake.  It’s not unusual to find one that has been run over on the road, but rarely have I found a carcass of one in the woods, especially this late in the year.  Gartersnakes usually are hibernating (often in groups) in rock crevices, rotting logs or holes dug by mammals by October or so.  The warmer-than-usual fall certainly allowed for extended basking in the sun and the ability to find active earthworms later in the season.   If you look closely you may see that this gartersnake has a blue tinge where it’s normally a greenish color. Yellow and blue pigments in a snake’s skin fuse to produce the green color in living snakes. After death, the yellow pigment breaks down very quickly, whereas the blue pigment is more stable and remains much longer. Gartersnakes that have been dead for a while can have bright blue dorsal and lateral stripes.  


Anthocyanins

Red maple leaves can already be seen scattered on the forest floor.  Their red color, as well as the purples of autumn foliage, come  from a group of pigments called anthocyanins.  Unlike carotenoids, pigments which produce yellows and oranges and are present in leaves year round, anthocyanins are produced towards the end of summer.  At this time phosphate, which has been helping break down the sugar that the plant has made during the warmer months, begins to decrease in the leaf, and this triggers the production of anthocyanin pigments.  The amount of anthocyanin produced is, in part, determined by the weather — cool and sunny days, and cold, but not freezing, nights all but guarantee brilliant foliage. Let’s hope the temperature drops a bit in the near future!