Rigor Vitae: Life Unyielding

Monday, August 03, 2015

WALRUS SOUVENIR


About his piece "Walrus Souvenir," the artist (not me) says:

"As president of the United States, George W. Bush pushed for exploratory drilling in the Arctic National Wildlife Refuge. More concerned with the need for energy than the harm it might cause Walrus habitat, President Bush argued for drilling because there were 'scientific uncertainties' around climate change. For the Walrus, however, the episode may harken back to President Chester A. Arthur (ironically known as 'The Walrus,' for sporting the manly mustache popular at the time) who entered office as the Walrus was on the verge of being hunted into extinction for the oil in its flesh that fueled gas lamps.

Walrus Souvenir is a meditation on the uncertain future for the Walrus and for the natural world when confronted with the priorities of Man. As a memento made from Man's own skin, it suggests that the product of his handiwork may one day be mass extinction, not only for the Walrus and for other animal and plant species, but 'humanity' itself, as their fate is closely tied with ours. As John Lennon sang, 'I am he/ as you are he/ as you are me/ and we are all together...I am the Walrus'"

Friday, June 05, 2015

AN OBSERVATION OF THROAT-PATCH DISPLAYING IN MALE POORWILLS

On May 30, 2015 I was hiking in Brigham Fork, a tributary of Emigration Canyon in Salt Lake County, Utah, just after dark, when I observed two Poorwills (Phalaenoptilus nuttallii) perched about half a meter apart on the ground. I watched the two birds in my headlamp beam through binoculars from a distance of about 10 meters. After some 30 seconds, bird B fluttered into the air briefly and landed, increasing its distance from bird A by about two meters. Ten or fifteen seconds later, bird A flew towards bird B, restoring the distance between the birds to roughly what it was before. About 45 seconds later, bird B flew away. some 10 seconds later, bird A also took off in the same direction. It wasn't until the next morning, when I looked at the photographs I took of the birds, that I was able to tell that both birds were males. In the photographs where both birds were perched close together, they were both clearly flaring their white throat patches and displaying them. Bird B also appeared to be spreading its tail, displaying the white patches there. Bird A's tail was obscured in these photos. I inferred this interaction to be a territorial rivalry, but the actual nature of the display is not clear. I was unable to discern any other behavior such as head-bobbing, but viewing conditions were far from ideal.  

I have not seen nor heard of Poorwills displaying in this manner. I sent this photograph to R. Mark Brigham, a Poorwill expert at the University of Regina, who told me he had never seen Poorwills do this either.

These birds are very interesting for a number of reasons, most famously for their manner of surviving winter's cold temperatures and lack of food resources. Hibernation is a common way for animals to deal with winter. Many birds, bats and even insects opt instead for seasonal migration, exploiting distant habitats during different seasons. A few, like the Monarch Butterfly (Danaus plexippus) and our friend the Poorwill use a combination of the two. Poorwills, relatives of Nightjars, breed in arid parts of western North America from southern Canada into northern Mexico; northern individuals seem to winter in the desert southwest. A number of bird species use daily torpor to minimize energy loss during cool nights or brief bad weather. Members of three related orders, the goatsuckers, hummingbirds and possibly the swifts, all show some abilities at metabolic adjustment, but none to the degree of the little Poorwill, which, in addition to its natural tendencies toward torpor, feeds heavily on beetles, rich in polyunsaturated fats, which remain liquid and metabolically 
available at low temperatures.I've watched Poorwills feed on darkling beetles on the ground, and have noticed that medium-sized ground beetles are usually common where there is a dense population of Poorwills.In the laboratory, these birds have been observed sustaining periods of torpor for over 80 days, and in the wild as long as 25 days. A shallow shelter, open to the southern sun is selected: a patch of cactus or rock niche to which the bird develops substantial fidelity. After sundown, the torpid Poorwill's body temperature begins to fall, until the ambient temperature reaches 5.5°C, an apparent optimum hibernating level which the bird tries to maintain. Solar radiation raises the body temperature daily, presumably allowing the option to forage during warm nights. I know of no human witnesses to a Poorwill rousing from torpor in the wild, but I imagine the bird backing out of his shelter to fully bask in the final evening rays, periodically flapping his wings to elevate his body temperature. It's not known how severe a winter these birds can survive, but a sufficient winter insect population, rather than temperature, is probably the limiting factor.

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illustrations:
(top): Photo by cpbvk
(center): Poorwill field sketch; pencil 11" x 8.5"
(lower): REANIMATION: POORWILL (2012) acrylic 30" x 20"

Friday, February 27, 2015

THE BLUE DRESS ILLUSION

This great optical illusion has been all over the internet over the past day, but in most cases people are asking the wrong questions about it. What's interesting is not whether you see a white dress with gold bands or a blue dress with black bands—it can appear either way to most of us. If you haven't seen both color versions of the same photo, keep checking back at the image, it's amazing to see the shift once it happens, and well worth the effort. I've been working with color professionally for nearly 30 years, and this is the first time I've been confronted with this illusion.

So what's going on here? During infancy our brains learn how to make sense of the confusing signals picked up by our senses, including sight. The wavelengths of light that enter our pupils are affected by many things, and don't necessarily represent the actual hue of an object very accurately. For example, the light bouncing off of a bird in a leafy tree will be tinted green by having also been bounced off of leaves. This is particularly easy to see with white objects. A white bird in that tree will appear quite green, although we will understand upon seeing it that it's actually white. Over the years, people have come to understand the way the brain interprets true colors from the false signals it's presented with, and codified it in the system of color theory.

One of the principles of color theory is the phenomenon of "simultaneous contrast," where one color seems to push an adjacent color towards its complement, or inverse color (blue, for instance, gives adjacent colors an orange tint and vice-versa). A well-known example of this principle happens when you stare at a red dot for a minute or two, then transfer your gaze to a white wall...a green dot seems to appear, the complementary of red. 


 The actual dress is blue with black bands, and these pigments are represented in the photo in question with various shades of two complementary colors: a purplish-blue-gray and greenish-golden-brown (above). The primary colors of light (blue, red and green) are different from those of pigment (blue, red and yellow), so pairs of complementary colors on a computer monitor differ somewhat from those on a painting; this illusion would not work with a printed version of the photo. The brain can translate the gold-brown and blue-gray bands correctly as the black and blue of the real dress. In that case, simultaneous contrast makes the blue look deeper than the actual colors in the photo. The brain can also assume the purplish-blue is color being reflected off of a white surface. This color, a sort of dirty light ultramarine, is very commonly reflected off of white surfaces that aren't illuminated brightly, which is probably why the the brain is so quick to make this mistake. In this case, it presumes that blue gray is really white, and that the golden-brown hues represent actual pigment, and simultaneous contrast intensifies them to make gold.

That's basically what's happening here, but it doesn't explain why the two colors don't enhance each other. Normally, when you set two complementary colors like these next to one another they exaggerate each other's brilliance, but in this case our brain seems to know that the colors in one set of bands are real and those in the other set illusory, because only one color or the other pushes the hue of its complementary bands to a more extreme version of itself. This is the strangest part of this illusion, and the one that's hardest for me to explain. It probably involves some assumptions our brain makes based on what we know about dresses and shapes, but more than anything, I think there's an odd (and unknown to me) principle of color theory of light that doesn't apply to pigment at work. I'm interested to hear any explanations you might have.

Wednesday, August 20, 2014

FORTY-FIVE YEARS AGO TODAY...

...the Beatles were recording the final session for Abbey Road. Three miles away, at Wessex Studios in Highbury, Robert Fripp and a new band christened King Crimson were recording “In the Court of the Crimson King.” Meanwhile, across the Atlantic, Miles Davis and a collection of jazz virtuosi, many of them not yet well known, were at Columbia's 30th Street Studios in New York City, recording Bitches Brew. While the Beatles wrapped things up on the 20th, both Crimson and Davis would conclude their sessions the following day.

Upon their release, all three recordings confounded the critics, few of whom recognized their importance, but in retrospect, one can't deny that they're three of the most innovative and influential (and, I would add, the best) albums ever made. Strange that they were recorded simultaneously...or is it?

Such multiple accomplishments in the arts have a lot in common with the technological multiples that have received a lot of recent attention, like the invention of the calculus, telescope and television, and the theory of evolution by natural selection, all of which were simultaneously achieved by two or more parties. The simultaneous nature of Abbey Road, ITCOTCK and Bitches Brew had something to do with the level of recording technology that had been achieved by 1969, as well as the introduction of new instruments like synthesizers and mellotrons, and the fact that the LP record album had been in existence for a generation and was now the comfortable standard of music consumption. Most important of all, though, was the artistic culture of that moment, a culture of ambition and innovation—a pale and wimpy version of the zeitgeist of the early 20th Century, but still not too bad, and something even to strive for now.
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Abbey Road cover designed by Kosh; In the Court of the Crimson King cover painted by Barry Godber; Bitches Brew cover painted by Mati Klarwein

Sunday, February 16, 2014

WHY THE LONG FACES?




I love Giraffes. We all love them: their big soft eyes, their improbable physiques, their quirky but undeniable grace. So it was no big surprise to hear the uproar when the Copenhagen Zoo killed a two-year old male Giraffe last Sunday and fed him to their lions. Nobody likes to see the life of a beautiful, exotic animal extinguished, and the natural reaction to hearing of this being done by a zoo (which is supposed to be a sanctuary for creatures, right?) is indignation at the least. But the basic reason for this giraffe's death stems from that basic love of ours for the animals. Few things draw visitors through the gates of a zoo like a baby Giraffe, so there's a strong financial incentive to produce a young one every year, whether you have any idea what you're going to do with it once it's grown up or not. So there's been an overabundance of zoo giraffes for a number of years. Some of these animals end up in private collections, or in places like “Dave's Roadside Zoo and Front-end Alignments,” or who knows where. Surely, many of them are relegated to lives of malnutrition and misery, and my guess is that less public Giraffe euthenizations are not unprecedented. The Copenhagen Zoo had a couple of offers from individuals and an unaccredited zoo in Sweden, but rather than accepting one of those they chose to kill their surplus Giraffe using a captive bolt stunner, the same way that cattle are slaughtered. I understand the anger at hearing this news, but I don't share a bit of it.

What I don't understand was the equal furor over the necropsy the zoo performed on the young Giraffe, and the fact that they allowed the public, including school children, to watch the process and ask questions about it. Most kids in the industrialized world grow up completely separated from normal ecological processes, from truly understanding how energy circulates through an ecosystem from one organism to another. The idea that sheltering children from this reality and preventing them from fully understanding the world is to their benefit, well, that's pretty hard to fathom. Besides, anyone who didn't want to see the necropsy didn't have to walk through the door. To me, the fact that the zoo put the meat to good use and used the necropsy to advance public education put a distinctly positive overall face on this sad but unavoidable event.

This blog's server doesn't have the capacity to list all the animal species that have been saved from extinction by captive breeding in zoos. We can only speculate at what future good will come from the breeding technology and understanding that continues to be developed in zoos around the world, not to mention their educational role (which I just did). Where you have life you have death, that's as true in a zoo as anywhere else. I, for one, am thankful to live in a world with zoos and am happy to appreciate all the good they do while accepting the less pretty realities that go along with them.
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illustration: FLAP-NECKED CHAMELEON & GIRAFFE (2002) acrylic on illustration board 30” x 20”

Sunday, October 21, 2012

Friday, April 13, 2012

BAT APPRECIATION WEEK (part ii)

The same factors that keep the average schlemiel oblivious to the bats around him make it difficult for the odd interested party to study and understand them; they live in a world to which we are deaf and dumb. Before night vision goggles could amplify ambient light and bat detectors convert ultrasonic calls to audible frequencies, bat researchers were relegated to observing their subjects leaving or returning to their roosts and collecting droppings and food waste below. The data collected were added to somewhat random information gleaned from trapping individuals at night, and the rest of the picture was by necessity speculative. Some species like the Spotted Bat (Euderma maculatum – above) of the American Southwest, long considered very rare, are probably less rare than hard to observe (although this species is one of the few in the U.S. whose echolocation call is audible to human ears). The gap is slowly being bridged, but mystery still reigns when it comes to bat behavior. Unfortunately, this makes it hard to assess, address, or even perceive a crisis when it hits, and it's hard to say whether the current decline constitutes the beginning of a crisis or not, but something's going on.

Being mostly small and delicate, bats are especially vulnerable to stress, injury and infection. Insectivorous bats are often exposed to pesticides, many of which have endocrine-disrupting effects. Frugivorous bats can also be exposed to agricultural pesticides when they feed on human crops, and in such instances are often subject to more direct violence as well. Bats reproduce slowly; a single pup per season is the norm. Of course, habitat destruction can be devastating. For some social bats, a small piece of real estate can be crucial to a large population. Over much of their range, the Pteropus bats of Asia, Australasia and Madagascar are hunted for food or as crop pests, and typically shun areas where they're disturbed by humans. Today, large Pteropus colonies are restricted to remote regions or small, uninhabited islands, like Pulau Kalong, a flat, one-mile-square, mangrove-covered atoll west of the Indonesian island of Flores. Nearly a quarter-million P. vampyrus roost here during the day, leaving each evening to forage on adjacent islands (below). Besides removing roosting and hibernating sites, deforestation diminishes insect populations and stresses individuals.

In much of the northern hemisphere, safety/liability fanatics sealed many natural caverns and mine shafts during the last century, lots of them in such a way as to prevent the entry of bats, destroying important roosts and hibernacula. Such was the case with Ezell's cave, between Austin and San Antonio, where a large colony of Cave Myotis (Myotis velifer) were inadvertently excluded by a gate in the late 1950s. Without constant bat guano enriching the cave's subterranean lake, the water's ecology became impoverished, resulting in a decline of its top predator, the Texas Blind Salamander (Eurycea rathbuni), and its honor of being the first species listed under the U.S. Endangered Species Act. Several attempts at reintroducing bats failed spectacularly, and no bats have taken the initiative to recolonize the place on their own, probably due to human activity in and around the cave. In fact, spelunkers have always been a bit of a scourge for bats, disturbing maternity and hibernating colonies. When aroused from hibernation, a bat's metabolic rate jumps, and when disturbed too many times it can starve to death. In recent years the caving community has begun to discourage its members from entering major roosts and hibernacula during crucial periods. It's difficult to establish the overall impact on a species when a colony abandons its digs, but human disturbance in caves appears to be a major factor in the decline of numerous species, including the endangered Gray Myotis (Myotis grisescens) and Indiana Myotis (M. soldalis).

Light pollution is another bat threat that's hard to quantify. Over most of the industrialized world, the night sky has changed remarkably. The effect this has had on nocturnal ecosystems is profound, but poorly understood. In the late '80s, a wooded area adjacent to my home was replaced with a well-lit supermarket. Over the next three years, the composition of nocturnal insect species in the area was completely rearranged. Exactly how these changes transmit to insects' predators isn't well understood, but important effects should be expected. A number of faster-flying bat species have learned to exploit streetlights and the insects they attract, while some other species seem to shun them.

Wind turbines have been vaunted as ecologically-friendly alternatives to coal-fired and nuclear power plants, but, as with any system, they have their down side, too. It's become apparent that in some situations, the frequency of bat collisions with these structures is far greater than chance would dictate. Of the 45 species of North American bats, 11 have been recorded as killed by wind turbines, none of them endangered. Of the recorded fatalities, over three-quarters belonged to three species: The Hoary Bat (Lasiurus cinereus), Eastern Red Bat (L. borealis) and Silver-haired Bat (Lasionycteris noctivagans). All three bats migrate long distances and roost in trees, Lasionycteris in tree cavities, and Lasiurus usually in foliage. More data are needed, but it appears that most bats are killed during the fall migration, and then mostly on still, overcast nights. To better understand the significance of this, let's look at the behavior of the best-known of these three species.


The beautiful Hoary Bat (above) is the most widespread, and over much of its range, the biggest bat in North America. Its sturdy foot-wide wingspan can carry it for amazing distances. It's the only bat to have successfully colonized the Hawaiian Islands, and it occurs on Bermuda and even Orkney Island, north of Scotland. A close relative was one of the few native mammals on the Galapagos, but it appears to have recently gone extinct. During the summer, males and females live separately, and many populations appear to consist solely of one sex, the females tending to concentrate in the east and the males in the west. A single female raises her pups each year in a group of spruce trees not far from my home. In September, migration and contact between the sexes begins, along with courtship behavior, including copulation and fighting between males. Hoaries may migrate singly or in flocks. Like many migrating birds, they seem to follow the Pacific coastline south, and it seems reasonable to expect migrating bats in general to follow shared flyways. The sexes live together during the winter, then separate for the spring migration. Females store sperm over the winter and ovulate in the spring, giving birth early in the summer. Lasiurus bats sport four mammaries instead of the normal two, and can give birth to as many as four, or in unusual cases, five, pups. The Hawaiian subspecies, L. c. semotus, is thought to have declined from habitat loss, and is listed as endangered by the U.S.D.I. The I.U.C.N. lists its status as indeterminate.

Courtship behavior probably has a lot to do with the huge spike of collisions during fall migration without a corresponding spike in the spring. Whether the increased mortality on overcast nights is related to increased migration activity or lower altitude of flight has yet to be established. Bats seem to be hit more frequently by turbines on tall towers, especially in wooded areas, but the available data are still rather poor. It is suspected that bats may be attempting to roost on turbines. Many fatalities seem not to result from a strike by the blade, but from rapid decompression from the vortex trailing behind it. At some sites, Mexican Free-tailed Bats (Tadarida brasiliensis) may be at special risk. Current research involving coating turbines with paint of varying UV reflectivity seems to indicate that a simple paint job could reduce mortality. As the nature of the problem becomes better understood, it seems likely that a safer wind farm regime can be devised.

In February 2006, a new and especially alarming bat threat was discovered. Bats in a hibernaculum near Albany, New York were found with a crust of white fungus on their face and wings. The fungus was originally identified as belonging to the genus Fusarium, a group primarily associated with plant disease, but including vertebrate pathogens as well. At the height of the Cold War, both the U.S. and Soviet Union conducted biological warfare research with Fusarium fungi. In 2008, it was determined to belong to another fungal family altogether, and was ascribed to the genus Geomyces. In 2009 it was identified as a new species: G. destructans. By that time, White Nose Syndrome (WNS), as it has come to be known, had spread to most of the known hibernacula in New York, and into Vermont and Massachusetts. Mortality of affected bats at these sites has been 90 – 97%, but it is difficult to gauge how many, if any, survivors make it through the summer. Each year has seen a rapid geographic expansion of WNS; its westward spread has crossed the Mississippi and it has ventured as far south as Alabama. The latter fact is surprising, since the fungus only thrives in cool temperatures. Whether the fungus is the cause of a fatal disease or just an opportunist associated with an unidentified pathogen is also unknown. Afflicted bats exhibit radical behavior change, including increased winter activity. They often fly about the cave entrance, even leaving it to flutter about in broad daylight on a frigid winter day. Not surprisingly, necropsied bats have shown depleted fat stores. The disease could be directly responsible for this, or it could be the result of increased activity and inability to find food, or both. Is the activity caused by hunger or vice versa? It's possible that the pathogen interferes with the bats' ability to thermoregulate. In the winter of '06 -'07, an infected bat was taken into captivity, fed up, and released in spring, which suggests that it may be possible for bats to fight the infection if their condition is sufficiently raised. Some articles have blamed global warming, but there is no basis for this. Within the affected sites, all cave-hibernating species have been found to be affected, except the Big Brown Bat (Eptesicus fuscus) and the Eastern Small-footed Myotis (M. leibii). The latter species, listed by New York state as a species of special concern, hibernates in different sections of the hibernacula, and work is underway to establish if they are infected; it's assumed that they are. Important populations of the endangered Indiana Bat (M. sodalis) are also afflicted. Eighty-five percent of the known population of this bat hibernates in 7 caves. Preliminary findings suggest that immune functions of infected bats may be significantly impaired. Some dead bats have been found without the fungus, and fungus has been collected from asymptomatic bats. In 2008, G. destructans was found on an otherwise asymptomatic Greater Mouse-eared Bat (Myotis myotis) in France, and a research team from the University of Winnipeg has just confirmed that the fungus indeed originated in Europe, where the endemic bats are far more resistant. Like Chytridiomycosis in frogs, which was also transported from abroad, White Nose Syndrome remains a darkened room with far more questions than answers, and the potential of real ecological devastation. Disinfection and general behavioral guidelines (similar to the ones established in 2007 for Chytridiomycosis) are being hammered out for biologists and spelunkers. Nine universities and a number of state and federal wildlife and health agencies are involved in studying WNS, along with a number of independent researchers. The U.S. Fish & Wildlife Service's Indiana Bat Recovery Team is overseeing distribution of funds.

According to the IUCN, nine bat species have recently gone extinct (six of them megachiropterans), 32 species (14 megachiropterans) are critical, 44 (9 megachiropterans) endangered and 172 (39 megachiropterans) vulnerable.
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Thanks to Laura Ellison
upper: SPOTTED BAT (2008) acrylic on illustration board 20" x 30"
middle: Pteropus vampyrum photo by CPBvK
lower: HOARY BAT (1993) acrylic on illustration board 17" x 12"