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Birding from Home

Enjoy this picture of a cheeky fellow visiting our neighbor’s tree.  He is a Hooded Oriole who, with his mate, like to set up a nest in the Spring.  This orange flowered tree is a favorite of the Orioles and the Hummingbirds.

Sometimes we take birds for granted.  We think they’re always there, all the time.  Unfortunately, songbirds are in decline due to serious predation by house cats, air pollution and various avian diseases like the West Nile virus.  Habitat loss is another serious problem.

However, many bird species are seasonally occurring.  Whether they are migrating through, stopping over or searching for nesting habitats you can study who’s here this month and who is coming soon.  Sometimes fellow birders will tip you off that a rarity or unusual visitor has been spotted.

Local birders said there was an unusual Mexican Red Egret at the slough.  It taught some of our local egrets to flap their wings while wading, herding little fishes into the shallow waters to become an easy dinner.

If you’d like to investigate your avian (bird) neighbors you’ll be more successful in the very early morning and late afternoon as birds are feeding.  You may find them going about their business any time especially when their preferred food and fresh water is available.  But, be careful not to set up a feeder or water dish where cats can attack. There should be a good 6’ clearance from shrubs or other cover where cats can hide.

A pair of binoculars (binocs) are very helpful and so are local bird guides. 

Ask family and family friends if they are birders and can help you get started.  Birders are great friends to have!

Here are some of my favorite guides and some of my favorite college level books.

Front and center:  Dr. Joel Carl Welty’s famous “Life of Birds”, 3rd ed.

Left front: “Life of Birds”, 4th ed.; Dr. Welty and Dr. Baptista

Left upper row: National Geographic “Birds of North America”

Upper row, center: “Audubon Society, Field Guide to North American Birds, Western Edition”

Upper row, right: The Shorebird Guide”, O’Brien, Crossley and Karlson

Lower row, right: “The Birds of Lake Los Carneros”, Millikan and Lewis

Why am I recommending “old” editions of Dr. Welty’s book?  Because it’s a classic college textbook and the old editions are more affordable!  Dr. Welty was my mother’s college professor.  He and his wife, Susan, were wonderful and caring people.

If you read older editions, please understand that names and classifications may change or be updated as new information is discovered, but, the beautiful line drawings are priceless. Many functions, parts or situations can’t be photographed clearly enough for viewers to understand.  (I used to be a Natural Science Illustrator!)

For the new birder, the color index and color photographs in the Audubon Society Field Guides are wonderfully helpful. Buy the guide new or used for your region! Often, you’ll see photos of both male and female breeding coloration which can be somewhat different than their round the year plumage. There’s plenty of information about the range where certain birds can be found, their preferred habitat, feeding habits and lots more.

I recommend that you start an informal field journal.  A simple “Composition Book” with wide-ruled lines is fine.  Practice your handwriting to be legible and neat so you can write your observations with an indelible (permanent ink) pen.  Keep that pen and a good number 2B drawing pencil with your Field Journal and binoculars at all times.  Wildlife biologists in earlier days would have used Acid-free paper and India ink in their field journals, so you’re off to a good start!

Find a good location where you can sit, comfortably, and observe the birds in the environment around your home.  Call this space your “field station” or “blind” (staying hidden so birds or animals are not disturbed by your presence).  

Tell your family that you are doing Science at a particular time of the day and to please not distract you as you are taking observations.

Among the many things you may want to record is the date, time of day, weather, wind and temperature.  You should try to be observing at the same time of day.  Note which birds are present, note what they are doing.

Start drawing as much as you can.  A quick impression is just fine, birds are rarely still.

Whether living in an apartment, in the city, in the suburbs or a more rural area, your home is essentially your habitat.  You are part of the local environment.  Lucky city dwellers in high-rise buildings may get to see Peregrine falcons “stooping” on pigeons, catching them for dinner.  Lucky hikers can sometimes see Peregrines in the windy habitat of the Chimney Rock Trail on Point Reyes, or, see Ospreys nesting on new nest platforms along Tomales Bay, CA. 

Don’t be too upset if you see a bird of prey (raptor) eating its dinner.  As I say to my kids, “Everybody needs to eat.”

During my ornithology (study of birds) course at University of California Santa Cruz, I didn’t see a lot of species (types) of birds at my field site as it was late in the year (no nesting going on).  I was patient.  One day I saw a huge dark raptor at the top of a redwood.  It could only be a Golden Eagle! My classmates doubted my observation, but on later days, I saw two Golden Eagles- one flying and another on a telephone pole at sundown.

In that class, we took field trips to the Point Reyes Bird Observatory (PRBO)and the California Academy of Sciences.  This was a chance to see mist-net capture of live birds, measurement and banding of their legs at PRBO.  The Academy had fixed (stuffed) bird specimens.  Your local Natural Science Museum will give you the chance to see fixed specimens on display.  Ask if you may sit, study and draw them!  

Here are some drawings that I made of a California Condor specimen at the Carrizo Plain Visitor Center, and, sketches I did of live juvenile condors at the Santa Barbara Zoo.  I guess I was hooked on Condors since my early teens when I saw a giant bird with wings wider than a picnic table flying in the wild over the Central Coast of California.

Last year, we noticed folks with binocs and cameras with long lenses staring down toward a remote beach. We stopped and these friendly birders said there are Condors on the beach!  Larger than big turkeys, they were walking on the beach then flying overhead!

If you get the “birding bug” you’ll have fun the rest of your life.  We have friends who travel the world trying to complete their “life lists” of birds seen and heard.  You can help with the Christmas Bird Count, helping observe and tally up all the species in your area.  

Thank you for joining us as we do Pandemic Projects, meant to keep you energized, curious and learning!

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The Science of Pigments

What Are Pigments? And what (and why) is color?

What are pigments? At Ancient Earth Pigments, we deal with pigments as powdered solids that are used as the coloring agents of paints or for other color-conferring purposes. But what is the origin of the colors pigments exhibit? A more scientific and general definition of a pigment is a substance that selectively absorbs light in the visible waveband. When you illuminate something containing a pigment with light, some is absorbed, some might pass through, and some of the light bounces back to your eyeballs. It is the selective nature of the absorption that gives rise to what we perceive as color: a pigment that absorbs all colors of light equally will look gray (or black), when illuminated by white light. If a pigment absorbs blue light, it could look yellow or red, because those colors are not absorbed. If it absorbs red light it could look blue, or blue-green. When you mix colored paints, you combine the absorption properties of the different pigments to yield new colors. White pigments are a special case – they don’t selectively absorb colors, in fact they reflect light very efficiently without absorption, which is why they will lighten color mixes – returning more white light to your eyes.

The color of the ocean (title picture) serves to highlight this well. Pure water is blue, because it absorbs red light. If you add plants to the water, it looks more green. The ocean near tropical beaches have a bright turqoise color because the blue color is modulated by the calcium carbonate white sand suspended in the water.

But how do pigments work, and what is absorption of light, really? To understand this it helps to think of light – or electromagnetic energy in general – as a stream of individual photons, where each photon is a little packet of energy. Each photon has a characteristic energy level, which correlates to its color. Blue or violet photons have higher energy then green, yellow, orange, or red photons, which in turn have more energy than infrared, microwave, or radio photons. Ultraviolet photons (and x-rays and gamma rays) have more energy than blue photons. If a chemical compound has a particular arrangement of its electrons that has a characteristic energy level that exactly matches a photon that encounters this compound in space/time, the photon can be absorbed. This means its energy goes into the chemical compound, and the compound gets excited, and this excitation can result in some work being done. Usually this just means the compound moves around a bit more – it heats up, basically – but in the case of what we call visible light (violet to red, on the energy spectrum), it can slightly rearrange chemical bonds, changing the shape of (for example) one of the pigments in a cone or rod cell in your retina. And that shape change stimulates a nerve impulse, telling your brain that (for example) a blue photon just went through your eye.

Infrared light is too weak to rearrange this bond, so we can’t see it, but we can perceive the heat energy that it can transfer. Ultraviolet light also does not rearrange bonds in the proper way – in fact it can break them altogether, or cause other undesirable chemical reactions, which is why ultraviolet light and X-rays and gamma rays are dangerous, even though we can’t see them.

Examples of absorption spectra of different pigments found in plants and algae, over a color spectrum showing the colors of the different wavelengths of light. The height of each peak relates to the probability that a photon of that color will be absorbed by the pigment.

But what are pigments, chemically? The particular arrangements of electrons that result in color in chemical compounds can be found in several different types of compounds: metal coordination complexes, organometallic compounds, and organic compounds. You probably already know that metals play important roles in pigments, but in pure metallic form, metals are generally shiny and reflective and don’t have much if any color. However, ions of metals are very reactive, and play important roles in biochemistry and geochemistry, and can in many cases make for brilliant colors. In some cases the color itself plays an important role.

Coordination complexes are individual metal atoms, in a particular ionic state, that are surrounded by other ions or molecules in a characteristic arrangement. The ionization state of the metal atom and the number and kind of the molecules bound to it all control the absorption properties of the complex, so the same metal can give rise to many different dramatic colors. The following table shows some examples of coordination complexes of iron (in two different ionization states), cobalt (Co), copper (Cu), aluminum (Al), and chromium (Cr). Many of these colors are found in familiar pigments.

Example of some coordination complexes that can occur in natural or artificial pigments. Via Wikipedia.

Coordination complexes often occur in natural minerals. Natural ‘earth’ pigments from mineral soils have red and brown colors that most often come from oxidized iron (Fe3+) complexed with water (H2O) or hydroxides (OH) yielding different shades depending on the exact combination of waters and/or hydroxides. These kinds of colors can be quite stable, which is why they have been used for over ten thousand years as pigments for painting and dyeing.

Organometallic compounds are a bit fancier but they rarely make good pigments because they are unstable and break down easily, resulting in disappointingly gray colors. They consist of a metal ion that has been chelated (bound up) by an organic molecule. A famous example of this is chlorophyll, in which a ring of carbon and nitrogen atoms surrounds a magnesium ion. Chlorophyll famously has two strong absorption bands in the red and the blue (see above figure), giving rise to the green color of plants.

The chemical structure of chlorophyll a. The part of the structure highlighted in red is the porphyrin ring, which also occurs in

Another famous example of an organometallic compound is heme, which the red-colored part of the oxygen-carrying protein in blood called hemoglobin. Heme consists of the same ring (red in the chlorophyll figure) only with an iron instead of a magnesium ion at the center. Both chlorophyll a and hemoglobin have amazing biological roles. Chlorophyll a molecules, when they absorb light energy in the blue or red wavebands, can ionize – give up an electron – the first step in photosynthesis. Hemoglobin, of course, selectively grabs onto oxygen molecules when they are abundant and gives them up when they are rare, making it the transporter of oxygen from your lungs to the far-flung parts of your body that need it. Unfortunately, organometals, while they are the spiffiest of biological pigments, do not make good painting colors as a rule.

The last category of pigments are the ones that are purely organic – meaning they consist only of carbon, nitrogen, oxygen, and hydrogen, no metals. These compounds achieve the same sorts of electronic arrangements as coordination complexes or organometals by conjugating lots of alternating single and double bonds between carbon atoms (don’t worry about this). Some of these are natural products, but many that we use are synthetic, produced in the laboratory or factory to be pigments and dyes. Some familiar pigments are the carotenoids that are found in colorful vegetables (orange in carrots is mostly beta-carotene, an organic compound), and the anthocyanins found in flowers. Indigo, an important pigment and dye, is an organic pigment derived from amino acids – but it can also be produced synthetically. Cochineal crimson, produced by South American bugs, is also an organic compound. The famous Tyrian purple is an indigo derivative produced by a marine snail. Many synthetic pigments, such as alizarin and azo dyes, are organic compounds similar to some natural products. In many cases, however, the natural pigments have different properties because of the presence of natural impurities or precursors or other pigments in the mix.

Some familiar organic pigments found in dyes, such as madder, don’t make good painting pigment powders unless they are treated with other chemicals (such as alum or calcium carbonate from chalk or bone) to make them precipitate into solids. This process results in lake pigments, and one form or another has been used for pigments and for dyeing since prehistory. In modern times lake pigments made from natural products have mostly been replaced by less-fugitive synthetic colors.

Detail of Titian: The Vendramin Family Venerating a Relic of the True Cross (ca 1550-1560).
Titian used rose madder lake in the crimson robes.

You don’t always need this knowledge of physics and chemistry to effectively use pigments in your artwork. However, it is kind of fun to understand some of the background behind the material you use, and some of the information may come in handy at some point. If you have questions, please make a comment and I will respond.

Thank you for joining us as we do Pandemic Projects, meant to keep you energized, curious and learning!