Purring Predators

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As agriculture took hold in Middle Eastern societies about 10,000 years ago, archeological evidence of cat domestication appears. When humans began storing grain, any rodent-killing animal was a benefit. But the presence of cats didn’t spread along with agriculture. Egyptians may have revered cats, but other civilizations used weasels or snakes to limit mice. In the painting “Lady with an Ermine” by Leonardo da Vinci, the weasel may symbolize purity or the young woman’s last name (similar to the Greek word for ermine). With all due respect, however, I think the animal may have just been the lady’s pet; weasels were more common pets than cats at that time.

ermine

Cats may have been popular in Egypt during the heyday of the Roman Empire, but Greeks and Romans kept weasels as their rodent-killing pets. Cats joined European families around the fourth century but were relatively uncommon until the 1600s (1).

Nowadays, of course, cats are popular pets and internet memes. Their omnipresence is also a major cause of concern to ecologists and bird lovers. In a 2013 research article, Loss et al. estimated our purring pets (and their feral cousins) kill about 2.5 billion birds and 12 billion rodents each year in the U.S. alone (2).

P.s. The adorable cat who posed for this painting is our own 18-year old feline princess, Flea. She’s killed exactly one bird in her life, a fledgling finch who accidentally flew into her mouth. Flea didn’t even bite down; the little bird panicked to death.

  1. The Oxford Handbook of Animals in Classical Thought and Life. G.L. Campbell. 2014. Oxford University Press.
  2. Loss, S.R. et al. 2013. The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications 4:1396.
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The Firefly and the Apes

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An old Philippine folktale pits a firefly against a troop of apes. One day, an ape asks the firefly why he carries a lantern. The firefly replies that he uses the light to see mosquitoes and defend himself. The ape laughs and calls the firefly a coward. Insulted, the insect challenges the ape (and all his friends) to a fight. The next day, the firefly faces 1000 apes with large clubs, all lined up against him. The firefly lands on the first ape’s nose and the second ape swings his club to squash the insect. But the lightning bug flits away and the ape’s blow kills his companion instead. Then the firefly alights on the second ape’s nose. A club is swung and the second ape is dead. On and on until the firefly reaches the last ape, who piteously surrenders. The folktale ends, “Since that time, the apes have been in mortal terror of the fireflies.” (1)

Despite folktales consistently portraying apes as fools, we all know they’re actually pretty smart. The Philippine tale is one account of why apes avoid fireflies. But could there be a biological reason for this aversion? Maybe it’s because fireflies are noxious.

One firefly can kill a bearded dragon (Pogona sp.), a fairly large lizard that can grow up to 2 feet long (2). For mammals like apes, well, they probably just taste really bad. Most animals that eat fireflies spit them out or throw them up.

Fireflies do try to warn their would-be attackers through their coloration. Light and dark stripes and red markings are examples of aposematic coloration – both are found on this lightning bug. Don’t say he didn’t warn you!

 

  1. Millington, WH and BL Maxfield. 1907. Visayan Folk-Tales. Journal of American Folklore. 20(79) 311-318.
  2. Knight, M et al. 1999. Firefly Toxicosis in Lizards. Journal of Chemical Ecology. 25(9)

Ecology of “The Force”

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As Obi-Wan Kenobi explained, The Force is “an energy field created by all living things. It surrounds us and penetrates us; it binds the galaxy together.” These sage words constituted my first exposure to an ecological idea: Energy.

Jedi are no fools. Every drop of energy we use (and rely upon) comes from outer space. Solar energy reacts with carbon dioxide and water inside those wondrous Earthly chemists, plants, to build the most amazing molecule of all – sugar. Sugars combine to form building blocks of plant bodies and, when eaten by an animal, these components break apart to release energy. We use this energy to power our bodies.

Life forms even store energy by combining sugars into fats or oils. The oil saved up by an unfathomable number of plants, buried millions of years ago, power our machines today. We call these ancient plant oils “fossil fuels.” Breaking apart those molecules releases the energy (and carbon dioxide) made long, long ago.

In a sense, that energy does surround and penetrate us; it flows through us.

May the Fourth (be with you) is Star Wars Day. Enjoy it by appreciating the energy of all living things that bind us together.

Ahh chooo! Pine Pollen and Climate Change

 

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The bane of many a Southerner’s existence is springtime pollen. All that yellow dust swirling on the breeze and coating your car, that’s pine tree sperm.

The male cones of a Loblolly Pine (Pinus taeda) look like a bunch of tiny bananas growing from twig tips. If you’re thinking, “wait, that’s not a cone,” the woody cone we use to hot glue decorative wreaths or smear with peanut butter for DIY bird feeders is the female cone. Its spirals of woody shingles (or bracts) protect the tree’s eggs and, after fertilization, the developing pine embryos inside.

Male cones are much smaller and shorter lived. They release pollen for a couple of weeks each spring. And it’s a LOT of pollen: 3-5 pounds per tree. Why so much? Pines transfer pollen from male to female cones by wind. It’s not a very efficient system. More pollen increases the chance of fertilization.

With Climate Change, pollen’s gonna get worse. Ladeau and Clark (2006) found that pines growing in an elevated CO2 environment produce more pollen cones, and more pollen, at younger ages.

p.s. If you ever wondered what a pine pollen grain looks like, it’s a microscopic Mickey Mouse logo!

Ladeau SL, Clark JS. 2006. Pollen production by Pinus taeda growing in elevated atmospheric CO2. Functional Ecology. 20(3) 541-547.

Is Your Favorite Animal a WUG?

AnimDiversity_RNG

Think of your favorite animal. Is it warm and fuzzy? Or fine and feathered?

Many people think of “animals” as mammals, birds, or reptiles. Occasionally a fish, crustacean, or insect will creep in there. But, let’s face it, our view of animals is limited.

Children reflect this discrepancy when asked to draw a picture of a habitat. For instance, Snaddon et al. (2008) found that children drew ~75% mammals, birds, and reptiles in their portrayals of a rainforest. In reality, rainforest animals are 90% insects.

The rainforest isn’t unique. Most animals are insects (beetles, to be specific). It makes the Victorian hobby of beetle-collecting seem a little more understandable now.

And the Nematodes! Nematodes (roundworms) make up a surprisingly high percentage of animal species. Scoop up a trowel-full of soil from your yard, and you’re likely to have thousands upon thousands of nematodes in there.

If we can get children to understand that ecosystems, like rainforests, contain more animals than just vertebrates (and plants too!), the consequences include a better understanding of ecosystem functions and conservation issues.

So introduce yourself and your children to insects and worms (sometimes called “wugs” – worms and bugs). Attend insect-related events at a museum, make insect-face masks for play, visit natural environments, sow insect-promoting native plants (and keep careful track of all the worms in the ground), or tend an insect or worm as a pet for a couple days.

Maybe your new favorite animal won’t have fur or feathers.

 

Snaddon JL, Turner EC, Foster WA (2008) Children’s Perceptions of Rainforest Biodiversity: Which Animals Have the Lion’s Share of Environmental Awareness? PLoS ONE 3(7): e2579. doi:10.1371/journal.pone.0002579

Student Illustrations on Scientific American blog!

Cicada_EOverbaugh
Cicada by E. Overbaugh

As a college professor, like all teachers, I relish my students’ successes. Today, I’m a whole jar-full of relish. My students’ work is posted all over a Scientific American blog, Symbiartic. Yay!

Please visit Symbiartic to see lots more student illustrations – and don’t forget to share with all your friends!

FrogFlukeOctopus_TBrownJLangJPark

Wildflower Stories: Part 2 (Tall Bluebell)

Bluebell_ATwildflowerslSee that Tall Bluebell (Campanulastrum americanum) flower? Is it red or is it blue?

Believe it or not, it’s kind of both!

The color pigment in plants that makes red is called anthocyanin. The pigment normally reflects red light waves. But if you raise the pH and add a couple metal atoms to anthocyanin, it changes the light waves reflected – and poof – blue!

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Turns out, blue is a pretty rare color in nature. Dr. David Lee wrote a whole book about how colors in nature come to be, including the fairly complex steps to making blue in “Nature’s Palette: The Science of Plant Color”.

If you’d like to check out the color pigments in the flowers around your home, visit Scientific American for an easy, do-it-yourself pigment experiment.