Hole-y Eggs

eastereggs

The hard shell of an egg may seem like a thin yet impenetrable fortress. At the microscopic level, though, it’s more like a colander. Thousands of pores allow oxygen into the egg (and carbon dioxide out) so the developing embryo won’t suffocate.

Those pores could potentially allow bacteria into the egg. In most birds, though, a thin layer of protein called the cuticle (or bloom) is added to the outside of the shell just before it’s laid. That layer blocks bacteria from moving inside the egg. Considering that eggs and waste products all pass through the same opening in birds, that cuticle can be extremely valuable. If you’re looking for the cuticle on eggs you bought at the grocery store, you won’t find it. Eggs here in the U.S. are washed before heading to market. The process is surprisingly complex since washing eggs improperly can cause bacteria to enter through those pores. It’s also the reason you’ll find eggs in the refrigerated section. In Europe, the cuticle stays on and eggs are sold at room temperature.

Our understanding of eggshell microstructure impacts Canada Goose populations. The process of “addling” by wildlife management professionals controls the population size of the birds. A thin layer of oil is rubbed on the outside of the eggshell, cutting off the oxygen supply for developing goose. The parents, who see a whole nest full of eggs, stop laying more. But only the un-oiled offspring will survive to hatch. [FYI: it is illegal to do this without a permit – see the Migratory Bird Treaty Act of 1918.]

Dinosaur eggs had pores too, and the structure and placement of those pores tell paleontologists a thing or two about how dinosaurs lived. For instance, some dinosaurs laid eggs in an exposed nest while some buried their eggs. Exposed eggs generally have fewer pores than the buried ones since gas exchange proves more difficult underground. Fewer pores are also found in eggs laid in dry environments to limit water loss. The Museum of Paleontology at Berkley has an excellent site with more information about dinosaur eggs.

Winter’s “Toasted Marshmallow” Egg Case

MantisEggs

This “toasted marshmallow on a stick” is the egg case of a Chinese Praying Mantis (Tenodera sinensis), containing hundreds of developing youngsters. The eggs overwinter in this protective case until the spring’s warm weather triggers the eggs to hatch into tiny nymphs (mini-mantids). Nymphs grow into adults who enjoy their summer, snacking on any and all insects who cross their paths. In the fall, Praying Mantises mate, lay their eggs, and pass away.

A female mantid’s work may all be for naught if a tiny parasitic wasp interferes. The mantis lays her eggs in a frothy matrix that hardens around her offspring; but this mini wasp (sporting a ridiculously long ovipositor and rear legs that look like the mantids’ front legs) can lay her eggs inside the mantis case before it hardens. Since the wasps hatch first, they’ll use the mantis eggs as food.

Thanks to Mike Dunn (Roads End Naturalist) who recently presented a guide to winter wildlife – tracks, chew marks, and insect sign. Not only was I awed by his amazing photos, Mike also brought samples of all sorts of wintertime insect egg cases (including this one), cocoons, nests, tracks and galls.

Where Art & Biology go to Shop

etsy

Thanks to everyone who’s encouraged me to set up a shop for the illustrations found on this blog and on A-wing and A-way – it’s now OPEN!

Welcome to RedNewtGallery on Etsy!

p.s. If you see any artwork on either blog you’d like posted in the Shop, just comment below and I’ll add it ASAP. For instance, the illustration from my most popular blog post (Penis Bones) is not currently on the site. Hope you can see why! Haha!

Creating Sketches: “How do you do that?”

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It’s a pretty simple process really.

STEP 1: I start with an object (either from life or from one of my photos) and draw a rough sketch in light pencil.
STEP 2: Outline in pen. I keep the lines I like, change the ones I don’t. And add a little more detail. The most fulfilling part of this process is erasing those pencil-sketch lines. The drawing really pops then!
I use Micron pens (waterproof – that’s important!).
STEP3: Add a light wash of watercolor.
Note: one aspect of my process is very unusual. For these little sketches, I use a 5×7″ sketchpad – not watercolor paper (crazy!). The water soaks in fast so I work pretty quickly.
STEP4: Add background.
By the way, I only use 12 colors: the reds (alizarin crimson & windsor red), yellows (new gamboge & aureolin), blues (antwerp & ultramarine), and six colors I just really like (yellow ochre, burnt sienna, cobalt turquoise, sap green, payne’s grey and perylene violet)
STEP5: Layer in another round of color. Intensify some areas, add color details to others, emphasize shadows.
STEP6: Sign, scan, crop, and upload.

Each piece takes 1-4 hours to create, the majority of that is spent on STEP2 (inking).

One very important (and unseen) part of the process is practice. I’ve been learning, trying (messing up), and experimenting for almost 30 years now. While most people think learning how to use watercolors is the key, it’s not. Learning how to draw is the most valuable tool. Once you have that firm foundation, the rest is icing. Enjoy!

Wildflower Stories – the Hercules of Plants

ATwildflowers_umbelCow Parsnip (Heracleum maximum) has a fascinating relationship with war, GMOs and sunscreen.

The plant’s scientific name probably points to its size – it’s taller than me (but that’s not saying much). It takes two years to grow that big. If you’re going to put that much time into growing, you’ll want to make sure nobody eats you; which leads us to the other possible reason for Cow Parsnip’s scientific name. Some claim Hercules used this plant medicinally.

Many plants contain chemicals to protect them from predators. This plant makes “furocoumarin”. In humans, furocoumarin combines with sunlight to cause a rash. This is where war comes in. During World War II, military organizations recruited plant and insect experts to investigate the defensive (or offensive) properties of these chemicals. Mustard Gas is similar in its blistering effect to furocoumarin.

Most plant predators, though, are not humans; they’re insects. As you can imagine, Cow Parsnip is very effective at deterring insect herbivores. So, the genes that will ultimately produce furocoumarin are prized. If you could insert those genes into another plant (how GMOs are made), the same protection will occur.

Beware the inevitable evolutionary “arms race” that results though. A few insects can eat Cow Parsnip, either due to mutations that let them break down the furocoumarins or behavioral shifts (like eating that plant only at night or when rolled in one of the plant’s leaves. Remember, the chemical has to be combined with sunlight to produce an effect.

And we get to sunscreens. A related chemical was used as a “tanning accelerator” up until 1996. Unfortunately, it caused rashes (“sun poisoning”), skin loss and even cancer. Turns out, furocoumarins can mutate DNA.

umbel

Cow Parsnip belongs to the Carrot family of plants. They tend to have hollow stems and flowers in “umbels” (like umbrellas). Some relatives are frequently on our dinner table (carrots, celery, parsley, dill, etc.); some, like hemlock (not hemlock), are deadly.

Wildflower Stories: Part 4 (Minty-fresh poop?)

ATwildflowers_mintBee Balm (Monarda sp.) is a member of the Mint Family – a group of aromatic plants that includes basil, lavender, rosemary, salvia and oregano.

How can you identify a Mint? Of course, the smell is a dead giveaway. That odor is actually a deterrent for herbivores. If a mouse eats a bit of mint, that mint scent will overpower the rodent’s sense of smell. So the mouse won’t be able to pick up a cat’s scent later on.

Some beetles have evolved to resist the essential oils of Bee Balm. When they eat the plant, oils condense in the beetles’ poop. They form the poop into a “shield”, waving it at any potential predators.mint_flower

Summertime Blues

dragonfly_bluDragonflies hover, swoop and twirl but never walk. They use their legs to trap their insect prey in a tiny six-barred prison before devouring them head-first. When guarding its territory along the water’s edge, this Blue Dasher (Pachydiplax longipennis) grasps a reed or blade of grass and waves his blue abdomen as a warning for other males. Females, in general, aren’t blue at all; they’re black with yellow lines running down their bodies While the name “dragonfly” may be confusing, other names – “snake doctor” or “devil’s darning needle”, for instance – are equally perplexing. No, dragonflies do not treat ailing snakes (or bring them back to life) and the insects don’t sew up any parts of you (although my Grandmother convinced me not to lie with the threat that dragonflies would sew my lips shut if I did). And in case you were wondering about that species name, it means “long wings”… not what you were thinking.