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.

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)

2nd Edition Now Available!

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Not my normal kind of post but when you publish a book, you need to put the word out.

Three years ago, I started collecting advice for a niece entering her last year of high school and planning to head off to college. What started as a one page list grew (generally when I met with my students and advisees). We all seem to make the same mistakes!

I ended up with a small book, published in 2014. It was so well received that some of my colleagues required the book in their classes (thank you!). I never expected it to be so successful – what a wonderful surprise!

Over the past two years, I’ve been editing and modifying (and adding specific examples in the appendices). And what perfect timing… my other niece is heading to college this fall.

So if you’re looking for a graduation gift for under $10, check it out! http://www.jmlandin.com/

A Raspberry’s Worst Nightmare

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With all the beautiful berries available now, I’ve been seeing more fruit flies hanging around the kitchen. Annoying? Yes. Ruining my strawberries? Nope. Fruit flies lay their eggs on damaged or rotting fruit. So they’re only interested in the pieces that are going bad. I’m ok with that.

But consider a fruit fly who lays her eggs on fresh fruit. She’d have the agricultural community freaking out. Just imagine the risk to berry crops. Actually, you don’t have to imagine because scientists have already done the calculations for you: it’s potentially $2.6 billion of risk (1).

Evolution has already dealt this stunning set of cards to Drosophila suzukii, the spotted-wing drosophila (2). The females have an ovipositor (the anatomical structure that deposits eggs) that looks like a serrated knife. Unlike the common fruit fly in your house, this species’ egg-laying parts can cut through the skins of raspberries, strawberries, blueberries, cherries, and grapes.

Want to learn more about the spotted-wing drosophila? IFAS at the University of Florida has a great info page on the little beastie (with horrifically gorgeous pictures, by Martin Hauser, of that ovipositor – if you haven’t seen fruit fly genitalia yet, you are missing out).

p.s. Thanks to Dr. Nadia Singh for introducing me to Drosophila suzukii.

  1. Walsh, Douglas, M. Bolda, R. Goodhue, A. Dreves, J. Lee, D. Bruck, V. Walton, S. O’Neal, F. Zalom. 2011. Drosophila suzukii (Diptera: Drosophilidae): Invasive Pest of Ripening Soft Fruit Expanding its Geographic Range and Damage Potential. Journal of Integrated Pest Management. 2(1): G1-7.
  1. Atallah, L. Teixeira, R. Salazar, G. Zaragoza, A. Kopp. 2014. The making of a pest: the evolution of a fruit-penetrating ovipositor in Drosophila suzukii and related species. Proceedings of the Royal Society B: Biological Sciences, 281 (1781)

Bee Bandits

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Flowers need bees. A bee’s job is to move pollen from one bloom to another; plants pay for the bee’s service with sweet nectar. Cunningly, some bees have found a way to get a paycheck without the work.

Carpenter bees (Xylocopa sp.) exhibit a behavior called “nectar theft.” Rather than reaching the base of the flower through its opening (and getting a pollen dusting in the process), robber bees bite a hole in the base of the flower to slurp up nectar, bypassing the pollen-yielding anthers entirely.

We can’t necessarily blame them though, as it may be the plant’s own darn fault. Flowers with long tube-like bases are more likely to get robbed since the brawny carpenter bees can’t reach the nectar any other way (1). This relationship may even keep the flower tubes shorter over evolutionary time, since short flowers are more likely to be pollinated (and less likely to be robbed).

In order to deter break-ins, some flowers have evolved thicker flower walls, new toxins, or even special relationships with animal “special forces.” Some tropical flowers produce extra nectar in a special chamber for ants, who act like police in stopping the robber bees (2).

P.S. The bees I watched for this sketch were upstanding citizens – no thievery going on here!

P.S.S. It’s a girl! This bee’s got a black face. Males have a large patch of white on their faces. (http://www.uark.edu/ua/arthmuse/carpbee.html)

  1. Navarro L and R Mendel. 2009. Relationship between floral tube length and nectar robbing in Duranta erecta L. (Verbenaceae). Biological Journal of the Linnean Society. 96 (2) 392-398.
  2. Gerling D, HHW Velthuis, and A Hefetz. 1989. Bionomics of the Large Carpenter Bees of the Genus Xylocopa. Annual Review of Entomology. 34:163-190.

 

Sometimes you DO choose your family (of geese)

gosling

What would happen if an adorable 3-day old gosling was placed between two wire enclosures, one containing a sibling, and one containing a same-age gosling from another clutch? Would the baby bird recognize its brother or sister and patter over to its relative?

The answer: yes… at least as often as dentists recommend sugarless gum*. In four out of five trials, the little puffball sidled up to its sibling rather than a stranger’s young’un.

There’s one catch. The youngest goslings (ages 3–9 days) prefer groups. Even if it’s a group of unfamiliar goslings, the little bird almost always waddled over to an unknown group rather than a single relative. By 15 days old though, the youngsters reliably reunite with their kin, no matter how small their family.

p.s. I created this image at an awesome carbon dust workshop, coordinated by GNSI-Carolinas, this weekend. Marlene Hill Donnelly from the Chicago Field Museum was our fearless instructor – she’s wonderful!

*Radesäter, T. 1976. Individual sibling recognition in juvenile Canada geese (Branta canadensis). Canadian Journal of Zoology, 54(7): 1069–1072

Ecology of “The Force”

OttersPond_850JML

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.