Sunday 21 April 2013

Colored Pencil Society of America Entries

Hello again!

As promised, I am trying to update this a bit more frequently. While these next drawings have already appeared in my deviantART page (http://jacquelinerae.deviantart.com/gallery/), I figured I'd post them here as well since the blog is a bit more easy to navigate to those non-deviants out there.

These were both done for the 21st International Exhibition for the Colored Pencil Society of America. These were particularly difficult for two reasons, the first being that applicants can only use reference photos that they personally took. Fortunately, I've been all over the place and have taken lots of cool pictures, so I selected a few photos of the bats at the bat rehabilitation center, Batreach, in Kuranda, Australia, as well as a few of the shingleback lizards I took while in Canberra, Australia. The other difficulty was resisting the urge to edit these in Adobe Photoshop after finishing them. Nearly all of my scientific illustrations, such as the whales posted earlier, are initially drawn in colored pencil and then heavily reworked in Photoshop. Since the two drawings featured here were specifically for a colored pencil competition, I was unable to make even minor digital adjustments!

Anyway, here are the drawings. The first is of a few Spectacled Flying Foxes (Pteropus conspicillatus). These enormous animals are in the aptly named group Megachiroptera (essentially meaning 'big bat'). Megachiropterans, or simply Megabats, are only found in the Old World and are primarily frugivorous or nectarivorous, meaning they feed on fruit and flower nectar. Their sensory adaptations reflect their feeding styles. Unlike the New World bats (Microchiropterans) that rely on echolocation to hunt fast-flying insects, megabats are unable to echolocate and rely primarily on their sense of smell and sight to find flowers and fruit on which to feed. Modern human activity threatens both megabat and microbat livelihood in myriad ways. If you are interested in helping to protect and preserve the world's bat biodiversity, I implore you to visit the Bat Conservation International webpage to find ways to help these glorious creatures.


'Flying Foxes' (aka 'Photobomb') 2013, prismacolors on illustration board
Me 'hanging out' with the spectacled flying foxes at BatReach in Kuranda, 2011

Second drawing is of the Shingleback skink (Tiliqua rugosa). I am not a herp expert, so I actually don't know much about these guys, other than to the untrained eye they look an awful lot like Banksia pods, which to an even less trained eye look an awful lot like pine cones. I fell in love with these lizards as soon I realized that they were neither pine cones nor banksia pods, but were in fact lazy, heavily armored lizards that enjoyed sunning themselves in the atrium area at the Australia National University. ANU had a wonderful little atrium in the middle of the biology building that housed an unbelievable amount of local biodiversity including these shinglebacks, water dragons, long-necked turtles, banksia, and even some really awesome rotting-corpse-smelling fungus that was attracting flies while I was there. 
Shinglebacks, 2013, prismacolor and derwent pencils on illustration board
Well, that's all for now.  I won't know the results of the competition or whether or not I'm even in the show for another week or so, but I will be sure to keep everyone updated! Wish me luck!

Thursday 11 April 2013

Updates and Whale Reconstructions



How did a year go by so quickly?? I started a new graduate program in May 2012 and have been fairly consumed with research, classes, and studying ever since.  Despite my new work load here at the University of Kentucky, I still find time to draw every now and then.  Since it has been so very long since I last updated, I will make this a super art-packed post! I have been channeling the majority of my creative energy over the past year into a series of ancient whale drawings. I am not finished with this project, but I am happy to share what I have done thus far.

The first is a reconstruction of Dorudon atrox. Dorudon is an extinct whale ancestor in the family Basilosauridae that lived approximately 33 million years ago during the Eocene. Unlike modern cetaceans, these early whales still exhibited hind-limbs as adults. The pelvic girdle is reduced or entirely absent in modern adult whales and dolphins, however Basilosaurids were still seen with small hind-limbs. These limbs may or may not have been external, but for the purposes of my reconstruction (and most others) they are placed on the outside of the body where they may have functioned in swimming or maneuvering. I based the shape of these hind fins on the recently discovered Japanese dolphin with fully formed hind flippers.

More well-known from this group was the enormous Basilosaurus. These serpentine giants were likely ambush predators that remained motionless at the bottom of the Tethys Sea floor until some poor hapless prey animal swam within striking distance.  In contrast, Dorudon was short and sleek, more similar in size and shape to a modern dolphin. Dorudon likely used its speed and agility to chase down fish and fast-swimming mollusks. Below is a skeletal reconstruction of Dorudon and Basilosaurus side by side for size comparison. The scale bar represents 1 meter. Yeah, did I mention these things were ENORMOUS?!


The second reconstruction that I’d like to share is of my personal favorite, Kutchicetus. Kutchicetus was a small, otter-like cetacean in the family Remingtonocetidae that lived around 45 million years ago. Fossils from this extinct were discovered in India by Dr. Hans Thewissen in 2000. Unlike the Basilosaurids, the Remingtonocetids were most likely able to walk on land in addition to swimming in the water, much like an otter. While the fossils that have been uncovered for this animal are absolutely stunning (particularly the skulls!), the feet still have yet to be discovered. Instead of taking artistic liberty in reconstructing the feet, I decided to just hide them completely in the vegetation. I still need to fix a few things on this drawing, particularly the muscles on the back of the head and the substrate (there were more clams/oysters at the bottom than I have depicted here), but overall I’m fairly pleased with the composition and color scheme. 

Also, to give you a sense for the bizarre shape of this animal’s head I’ve included an older illustration I did for Dr. Hans Thewissen’s 2009 paper in Journal of Paleontology. It made the cover!

The final whale I will be sharing is Ambulocetus natans. Ambulocetus, which literally translates to ‘Walking Whale’, was also discovered by Hans Thewissen in the early 1990’s in Pakistan and is one of the earliest whale ancestors, living around 48-50 million years ago. Ambulocetus was an enormous ambush predator that inhabited both saltwater and freshwater mangrove environments. I tried to show off its crocodilian-like ambush hunting style in my reconstruction where I have depicted one particularly large animal leaping out of the water at an Eocene waterfowl.  Ambulocetus had very large hind feet and powerful hind legs that appeared to be better adapted to swimming than walking on land but, as its name implies, it was able to both walk and swim. 


Well, that’s all for now.  I will have a few more whales and many more birds and insects in the near future, so stay tuned! 
-Jacqueline

References:
S. Bajpai and J. G. M. Thewissen. 2000. A new, diminutive Eocene whale from Kachchh (Gujarat, India) and its implications for locomotor evolution. Current Science 79(10):1478-1489

J.G.M. Thewissen, Sunil Bajpai. (2009) New Skeletal Material of Andewsiphuis and Kutchicetus, two Eocene Cetaceans from India. Journal of Paleontology. 83: 635-663

J.G.M. Thewissen, S.T. Hussain, and M. Arif (1994). "Fossil evidence for the origin of aquatic locomotion in archaeocete whales". Science 263 (5144): 210–212

Sunday 4 March 2012

Cedar Waxwing

Hello Folks!


I'm shifting focus away from arthropods today and introducing one of my favorite bird species, the cedar waxwing (Bobycilla cedrorum).  I tend to see these birds hanging around streams and lakes feeding on various red berries.  The bird in my drawing is feeding from a dense species of serviceberry (Amelanchier sp.).  Although I've been fortunate to spot watch these birds through binoculars on multiple occasions, I actually didn't know much about cedar waxwing biology before attempting this drawing.  I will share with you a few interesting facts I found on the Cornell Lab of Ornithology webpage about these beautiful birds.  
Drawn with prismacolor colored pencils on colored matte board.


The first bit of information I found interesting about these birds is that they are apparently one of the only North American birds that eat fruit year round.  Like all adaptations, their specialized diet comes with costs and benefits.  Because berries aren't very nutritious, the birds need to eat a fairly large quantity of fruit to extract the nutrients they need.  Sometimes this need to intake large amounts of berries can lead to foraging errors in which birds can potentially poison themselves by feeding on berries that have fermented on the branch.  On the other hand, this specialized diet can also protect them from brood parasitism.  As many of you may know, Brown-headed cowbirds are brood parasites that lay their eggs in other birds' nests, forcing their hosts to take care of their offspring.  Often the hosts can lose their entire brood to starvation when there is a cowbird in the nest.  Because the cedar waxwing diet consists almost entirely of berries, cowbird chicks deposited into their nests often starve to death.  While I haven't found any data on this, I assume that because cowbird chicks often do not survive in cedar waxwing nests, the cedar waxwing's chicks are more likely to survive a cowbird parasitism event.  





Detail of cedar waxwing.

Life history information taken from:
http://www.allaboutbirds.org/guide/Cedar_Waxwing/lifehistory/ac

Reference photo from Robert Harrington (An awesome bird photographer!):
http://robert-harrington.com/


Thursday 5 January 2012

Sketches!


Hello everyone!

Sorry for the long break but I just went through a few very crazy months.  I'm changing PhD programs at the moment and that has basically required all of my attention.  I have, however, found some time to start drawing in a little Moleskine sketchbook I picked up at the beginning of this semester.  I decided that if I can't find the time to create full-size drawings anymore, I can at least do some small-scale, no pressure drawings in my sketchbook that I can share on here.

So, here are a few of the drawings I've done so far...


Nectarivores and bee balm.

The first sketch is of a few nectarivores (Ruby-throated hummingbird, Anna's hummingbird, Hemaris sp. hawkmoth, and an extraordinarily large honeybee) feeding from a bee balm (Monarda sp.) flower.  I decided to do this drawing for a few reasons.  First, I really need to improve my botanical illustration skills, so why not start with something that allows me to include subjects I'm already comfortable with, such as insects and birds?  Second, I've just never drawn a hummingbird before and was curious about the difficulty involved with drawing metallic feathers.  And finally, I've seen three of the four species pictured here feeding at bee balm in my home town and it's just one of those things that always seems beautiful and special, no matter how often you encounter it.
Spectacled flying foxes.

The second sketch is of five spectacled flying foxes (Pteropus conspicillatus).  Again, in an attempt to improve my botanical illustration skills, I chose a subject that would allow me to include both animals and plants into the composition.  I have had a special fondness for these bats ever since my trip to tropical North Queensland where I had the opportunity to witness hundreds of these massive bats leaving their roosts in the evening.  Whether creating a cacophony of chattering squawks from their roosts or taking to the wing in the hundreds, these megabats truly are one of the most spectacular animals in the world to observe in the wild.


Passalid beetles!


The last sketch I feel like sharing tonight is of a fascinating little insect called the passalid beetle.  It's also known as the bess beetle, betsy beetle, or patent leather beetle in North America.  I actually have a few colonies of these beetles in observatory cages in my house at the moment that I've been monitoring.  These beetles form monogamous pairs and males and females contribute equally to care of larvae.  Parental care on its own is pretty awesome, but these insects take it to the next level by incorporating cooperative brood care.  This means that adult offspring of the monogamous pair will remain in the natal nest (in this case, a rotting log) and help care for their younger siblings by building pupal cases and possibly feeding larvae.  As young adults, that is, post pupation and pre-dispersal, the exoskeletons of these beetles are not fully hardened.  This is why several of the beetles in the drawing are orange or red; the lighter color indicates a lack of pigment developed by the younger offspring.  I could go on for days about these beetles, but I will cut my summary short.  Take home message is that these beetles are beautiful live in cooperative family groups in rotting logs.

'till next time,
Jacqueline

Wednesday 13 April 2011

Velvet Worms!

(Pan) arthropod #2
Our second arthropod is actually not an arthropod at all!  It is an onychophoran, which is a close relative to the arthropods (they both belong to the larger group Panarthropoda).  Onychophora is a peculiar group of spongy, arthropod-like worms that have legs, segmented bodies and claws.  Oh, and they also shoot adhesive slime for their heads for prey capture.  For those of you who haven’t had the pleasure of being “glued”, I assure you that the slime is extremely effective at both subduing prey and attaching the worms’ bodies to human fingers.  To be honest, I didn’t know much about this group at all until just a few weeks ago when I had the opportunity to collaborate with a world expert on Oncychophora biology, Dr. Dave Rowell, who studies a native Australian velvet worm, Euperipatoides rowelli.  
Live E. rowelli caught in Tallaganda State Forest.
I found this species particularly interesting because it shows evidence of social behavior.  For instance, there is a social hierarchy in groups of E. rowelli.  Dominant females feed first on prey while the other subordinate worms wait their turn.  Dominance is established in these aggregations the same way it is generally established in other social groups- through aggressive behavior.  In this case, the aggressive-dominant worms bite and chase the passive-subordinate worms to establish their hierarchical positions.  
Drawing of Euperipatoides rowelli as they appear inside a rotted log.
Created with prismacolor colored pencils on orange matte board.


Another interesting finding with regards to this species’ social behavior is its ability to potentially recognize kin.  It has been shown that velvet worms that have been taken from the same log are tolerant of one another, however, if they are confronted with worms from a different log they will attack and kill the foreigners.   The ability to recognize relatives is extremely important in evolutionary theory because it has long been believed that altruistic behavior evolves when the organisms that cooperate are closely related.  In order to cooperate with relatives it is necessary to recognize relatives.  I find the evolution of kin recognition particularly fascinating because that is exactly what I am studying in the Australian social huntsman spider!
Detail of youngster and big adult's head.

What I enjoyed the most about creating this drawing was that I was able to work with both live specimens that we brought back from the field as well as some amazing reference photos taken by a fellow artist and scientist at ANU.  While keeping several of these live worms in my apartment I was pleased to observe that many of the large females we had captured were giving birth to lots of baby velvet worms.  And yes, you read correctly, they were giving LIVE birth- not laying eggs.  While some velvet worm species have actually independently evolved a true placenta-like connection between the embryo and the mother, E. rowelli does not supply the developing embryos with anything more than the original yolk in the egg. The eggs hatch within the mother worm a few days before she “gives birth” to them.  The small gray worm in the upper right-hand corner of my drawing is roughly the relative size and color of a newly born baby onychophoran.