Red-winged Blackbirds - Agelaius phoeniceus


July 28, 2008

I will admit, these are not my favorite birds. The male of this species breeding season territoriality encourages it to dive bomb anything it sees as a threat to its harem of up to 15 females; including Homo sapiens. A museum employee recently strolled into the zoology prep lab complaining about a Red-winged that had set up shop along a museum campus sidewalk, and was aggressively swooping innocent pedestrians, of which she was one. She half jokingly suggested that it might make things better if she attached a Red-winged study specimen to her head. If it were a male specimen, that would probably make things worse!

Faulty deterrents aside, I was sympathetic to her irritation. Last year, whilst staying at a friends farm, I stepped out for an early morning jog along one of the many winding, rural roads. I watched my shadow, and to my dismay, about every 50 feet watched another small, bird-shaped shadow swoop in over my head. Male Red-wings had stationed themselves quite evenly along my route, and sat perched on electrical lines waiting for any intruder (me) to dare enter their territory. They cawed and flashed their bright red wing epaulets in warning before diving within range of my noggin. I can't blame them for being protective of what they perceive to have rightfully claimed, but it's hard not to take it personally. Geez.

So, when I was commissioned to do a painting of one of these suckers, I hesitated at first. How can I paint my sworn avian enemy?! I then realized that in a two-dimensional state, there was no threat of it going after anyone. Red-winged blackbirds belong to the family Icterids that also include (until DNA evidence proves otherwise) grackles, meadowlarks, bobolinks, orioles, and cowbirds. A highly polygamous species that can be found throughout North America, it exhibits a high sexual dimorphism with the adult males being a glossy black with bright red and yellow wing epaulets, and females being brown and streaked. Kamikaze antics notwithstanding, it's a handsome species worthy of our respect.

Drawing lessons and an Accipiter cooperii


July 15, 2008

I went in the museum an extra day last week to indulge in some painting; something I have not been able to do much of lately. I wanted to work a little bigger than usual, and rather than working from a static study skin, I looked for mounted specimens. There was a decent mounted specimen of a Peregrine Falcon I have been eyeing for some time, but I settled on what looked to be a juvenile Cooper's Hawk or Sharp-shinned hawk. It looked too large to be a Sharp-shinned. In any regard, I treated it as a Cooper's and altered the plumage coloring to reflect that of an adult. Dave helped me to locate an adult specimen to used as a reference. He pulled out a male from a drawer and I was taken aback by its rather petite size. I then remembered that the males of this species and of Sharp-shinned are considerably smaller (by several inches) than the females.

Drawing from a three-dimensional object seems so much more difficult for me than drawing from memory or a photo. I would draw a line and glance up at the hawk, only to have it stare back as if to say "Don't you think my wing is a bit too short? Grrrrr!" Observing and drawing in this manner is an exercise, and if not done on a regular basis I find the skill will quickly languish. My first couple attempts to sketch the creature were a bit rusty, but I eventually got it worked out well enough. I painted for 3 hours, and relished the luxury of sitting in the quiet meditation of observation, and drawing.

7/22 - Just posted to the Etsy Shop.

Blackpoll Warbler - Dendroica striata


July 08, 2008

Last week at the museum, one of my specimens was a male Blackpoll warbler. Dave handed it to me with an apologetic wince: it was extraordinarily fat. Dave stated normal weight for a spring Blackpoll was around 12 -13 grams, but this fellow logged in as 17. No big shakes for a species of our size, but for this tiny fellow, that's a huge difference. Birds with large amounts of fat can pose a bit of challenge to creating a clean, and neat study skin. As much fat as possible must be removed from tissue, otherwise, its oils will soil the feathers, discoloring the specimen over time. Despite the amount of fat that had to be removed, my specimen turned out relatively clean.

As I was finishing up for the day John Bates, Zoology Chairman and Associate Curator of Birds, wandered into the prep lab and said "Oh a Blackpoll! Do you know about these?". My blank stare encouraged him to lead us to the zoology office, where he swiped a rather faded world globe from the desk. The globe had worn out areas on it, presumably as a result of just what John proceeded to do. He pressed his forefinger into Alaska, stating Dendroica striata bred there and throughout the boreal belt line. He then dragged his finger down to North Carolina and paused. He explained, while proceeding to drag his finger down to Venezuela, that there is evidence that Blackpolls on their way back south pause in North Carolina and other areas of New England. They gorge themselves and double their body mass before making an extraordinary 3000k, 88hr nonstop flight over water to their wintering grounds in northern South America. There is no evidence that the little birds stop on any islands along their herculean ocean trek. Somehow, by John using a physical globe to illustrate the migration path and length, it was made more impressive than if he had pulled up Google Earth.

Following up at home, I found data stating Blackpoll non-fat weights ranging from 8 to 11 grams, and their fueled up state tipping the scales at roughly 22 grams. My 17 gram fellow, being a spring bird, was on his way north to a boreal breeding ground. Poor fellow, he had crossed oceans with energy to spare, only to smack into a downtown window. On the brighter side, what I love most about volunteering at the museum is having a brief conversation such as the one above that will forever illuminate a previously unfamiliar species, and spark again my utter awe and wonder at the natural world. At the very least I was inspired to get a globe for the home studio. I opted for raised relief, and "natural" coloring; no pink and purple countries for me. I stuck with the home town team: Chicago's own Replogle.

*painting is in Etsy shop.

Of Cranes and Herons


July 02, 2008

I've been asked by my lovely, butt-kicking, just returned from bike tour of Maine friend, Christy, to clarify the difference between herons, and cranes. This is something that has come up several times recently, and I even heard Dr. Willard explaining it to someone on a tour of the bird collections a couple of weeks ago. The assumption would be, because they look similar, that they are closely related, and from the same family and order of birds. This is not the case. While they share many similarities of appearance (long neck, legs, and spear-like bill), and even some types of habitat, these similarities are largely superficial.

Let's start with taxonomy. Cranes belong to the family Gruidae. Gruids have 15 species worldwide, two of which are native to North America: the rare Whooping, and the Sandhill. Gruidae fall under the order gruiformes, which include rails(family Rallidae), and the lone Limpkin(family Aramidae). Herons, egrets and bitterns, belong to the the family Ardeidae, which fall under the order Ciconiiformes, **which also includes the New World Vultures, spoonbills, and storks. You can take an order like the Gruiformes, and upon first glance at the various species, there is much morphological diversity. For instance, rails, such as the Virginia Rail, are small, secretive, water loving birds, whereas cranes, such as the Sandhill, are very large, gregarious, and prefer the wide open habitat of prairies, farm fields and meadows. Despite these differences, however, molecular evidence would suggest that they are, in fact, somewhat closely related.

Herons, egrets, and bitterns are quite solitary, and pretty strict carnivores; spearing anything that moves (fish, frogs, and sometimes the chicks of other species of birds). Cranes tend to congregate in large flocks, have pretty complex mating and territorial rituals (cranes are famous for dancing) and are more omnivorous. The most easy distinction to note between a crane and a heron, or egret when in the field is that cranes fly with their necks outstretched, whereas herons and egrets will tuck it in. Even when not flying, one can see the distinctive snake-like, s-curve in the neck of heron and egrets; a feature that allows them to strike prey with lightening speed and precision. While crane necks are also long, elegant and do curve, they don't curve or crook quite the way a heron's neck will.

So, those are the basics. From there you can get into suborders, subspecies, fossil records, molecular evidence, and so on, but the short answer is despite outward appearances, herons and cranes are not closely related. While I can take no responsibility in regards to the accuracy of the information contained in this post, I can safely say this: they both eat frogs; lots and lots of frogs. That's for you CP

**7/27 update - It looks as though recent DNA evidence would show that vultures are more closely related to hawks than storks.

Tiny Aviary All rights reserved © Blog Milk - Powered by Blogger