The Grey Parrot Anatomy Project serves not only to discover ‘anatomy’, it also was created to develop diagnostic and treatment technologies that can be used here and now on living animals (including humans). Team members come from many walks of life and scientific disciplines.  Each researcher brings a unique set of skills and, in some cases, a student force to help tackle problems encountered through the research process.

Dr Scott Echols

Dr Echols with Einstein

Dr Scott Echols- Principle Researcher, Project Coordinator, Co-Author

Dr. Echols is a board certified avian specialists with over 20 years of experience in practice, teaching and research.  His main interests are avian surgery, nutrition, kidney disease and improving the behavioral health of captive species.  Dr. Echols is the co-founder of Mobile Avian Surgical Services, founder of Avian Studios and Scarlet Imaging, a frequent author and lecturer and has created educational DVD’s and other videos that have been viewed worldwide.


Dr Ed Hsu

Ed Hsu - Principle Researcher, Imaging Coordinator

Ed Hsu- Principle Researcher, Imaging Coordinator

Dr. Ed Hsu is the co-director of the Grey Parrot Anatomy project, and runs the Small Animal Imaging Core Facility at the University of Utah, the only publicly accessible small animal imaging facility in Utah.  He is an experimental imaging physicist with more than 20 years of experience in developing advanced imaging technologies and their applications in pre-clinical biomedical research.

“I am primarily responsible for acquiring images of the anatomy and physiology of the organs in animals that Dr. Echols and our collaborators want to study,” Hsu said. “Most of the time we can just apply existing imaging technology.  Sometimes we need to push the envelope a bit to get what they want.”

Hsu has experience with flow, functional (brain activation), diffusion, and molecular MRI. Additionally, he has experience with CT, PET, SPECT, and fluorescence tomography imaging modalities.

“I am best known for my theoretical work in the MR methodology for measuring anisotropic diffusion, now known as diffusion tensor imaging (DTI), and for applying it to characterize fiber orientations of the myocardium,” he said. “From MRI evaluations of tissue or organ microstructure, through various collaborations, my research interest has now expanded into imaging and modeling structure-function interactions in cardiac and soft tissues.”

Besides Hsu’s current research characterizing myocardial structures with DTI, he is also focusing on accelerated MRI, general DTI methodology, pre-clinical MRI, and most recently, image-based cardiac mechanical modeling.


Professor Mark Nielsen

Mark Nielsen - Anatomy Coordinator and Chief Anatomist, Co-Author

Mark Nielsen- Anatomy Coordinator and Chief Anatomist, Co-Author

Mark Nielsen is an anatomy professor and frequent lecturer and author.  As one of the most frequently published authors in human anatomy textbooks and digital applications, Mark is a highly sought after lecturer, writer, reviewer and researcher.  Mark’s publications include animal anatomy and he has extensive experience in detailed dissection and comparative studies.


Scott Birch

Scott Birch, 3D art design GPAP

Scott Birch has been focused on the technique of translating CT/MRI/PET data into interactive 3D models or visualizations for over two years, and his first concentration was on veterinary cardiology.

“In 2014, Dr. Ashley Saunders at Texas A&M had a heart murmur project that required visuals of specific congenital heart defects, and we were stumped,” he said.  “I remembered a not-too-successful technique I had attempted in 2008 at Cornell University to visualize anatomy for regional nerve blocks, so I tried again with an updated toolset. Through many months of trial-and-error, I finally honed in my technique and was able to build 3D models successfully, visualize complex anatomy in an interactive environment, and even print replications of patient-specific anatomy.”

In this pursuit of knowledge, Birch needed extremely high resolution data sets to unlock the potential of his technique, and thus became involved with the Grey Parrot Anatomy Project.

“Dr. Echols has used his new contrast agent, Brite-Vu®, to perfuse a parrot and then CT scanned at 100 micron resolution, which was the highest resolution scan I had seen so far,” Birch said. “He shared with me over 17 gigabytes of data—an incredible puzzle for me to re-build as a 3D model.  It took me months to segment the tissue, isolate the structures within, and add color and material to the 3D models.”

Once Birch has the 3D models, he can rotate them to any viewpoint, change transparency or translucency, add clipping planes, or otherwise modify them to yield the final render.

“These images are just as much art as science, and my goal is to make them as beautiful as possible while also showing the areas of interest to scientists and educators,” Birch said. “I am not a scientist, researcher, or bio-engineer, but rather an artist who is borrowing techniques from all of these different disciplines to produce my work.”

Birch hopes to 3D print the parrot’s vascular structure at 25x real size, or over 2 meters from head to claw if possible. He said the models can also be shared with other educators and researchers across the globe.

“One bird could be shared across the entire globe, essentially living forever,” he said. “I think that’s pretty cool.”


Dr Casey Holliday

Dr. Casey Holliday, associate professor of anatomy at the University of Missouri School of Medicine, combines techniques from different fields to understand the biomechanics and evolution of the skulls of birds and crocodilians.

Using iodine contrast-enhanced micro CT imaging, histology, and biomechanics, the Holliday lab has created 3D models of parrot heads to study cranial kinesis.

“Cranial kinesis is the phenomenon that parrots and many birds, snakes and some other animals have in which they can move joints in their heads other than just the jaw joint,” Holliday said. “A parrot can elevate its beak across the hinge joint its face, so it can husk fruits and nuts, or use its bill to climb around on trees. There are all these extra mobile joints and muscles that allow them to do this behavior which I find fascinating. Parrots are pretty phenomenal example of kinesis.”

By creating a 3D model, the researchers can shed light on how parrots are able to generate such high bite forces and move their bills dexterously.  They are also able to see how different muscles load force at different points in feeding.  Some of this data will be used as part of the Grey Parrot Anatomy Project.

Ian Cost, a PhD student at the Holliday lab, is currently studying adaptations to bone and cartilage among different bird species to understand how some birds are able to generate high forces in their heads without breaking bones. For example, ducks have flexible bones in their jaws that can bend up to 30 degrees without breaking.  Parrots, on the other hand, need to have extremely strong bones in order to crack open nuts with ease.

Recently, the lab has also been able to compare CT images of the Kea and Kakapo, both parrots from New Zealand.

“Grossly speaking, you can see just from their head shape that they can do really really different things with their heads,” Holliday said. “They are more closely related to each other than they are to other parrots, so the argument can be made that their anatomy diverges so much so that they can occupy different ecological niches.”

While most of the lab’s work is in the realm of basic sciences, Holliday said eventually the research could have clinical applications for treating disease processes like arthritis, fractures, or beak malocclusions.

The Holliday lab’s research was recently featured on the cover of the Journal of Anatomy.


Dr. Dominique Homberger

Dr. Dominique Homberger is a comparative anatomist and Andrew Clinton Pereboom Honors Professor at Louisiana State University.  She is currently in the early stages of analyzing the anatomical base of palatine luxation in parrots.

“My research on the palatine luxation research is a collaborative project with Scott Echols and Julie Hebert, who collected the first observations of this problem,” she said. “I plan to look into the anatomical reasons for this malfunction.”

According to her website, Homberger’s research projects are tied to a “fundamental interest in the reconstruction of macroevolutionary changes as a result of individual variation and natural selection by synthesizing functional-morphological and behavioral-ecological data of extant organisms with paleoclimatological and geological data.”

Beyond her palatine luxation research, Homberger has been working on a long-term study of feeding and drinking behavior, functional morphology, ecology, and evolutionary history of the Psittaciformes.


Jackie Houser

Jackie Houser

Jackie Houser is a member of the DVM class of 2018 at Oregon State University.  Houser is currently helping Dr. Sarah Nemanic with a interactive online project designed to teach normal radiographic anatomy of birds, dogs, cats, and horses.

“The program currently includes dog, cat, and horse radiographic anatomy, but I have an interest in avian medicine, so I joined with the intention of adding a few avian species to the program to help the bird lovers like me out there,” Houser said. “It’s designed to be interactive to help create an association between the structure on an image and the name of the structure, in order to help facilitate learning normal radiographic anatomy.”

Houser and Nemanic currently have normal radiographs from a red-tailed hawk, domestic duck, and chicken, but are hoping to expand the project by gathering more images of pet bird species.

“In order to be able to recognize something as truly being abnormal on a radiograph, you first need to know what is normal,” she said. “Since veterinary students don’t receive as much exposure to avian anatomy as we do other species, I thought it was important to try and expand the resources and tools available for learning normal avian radiographic anatomy.”

Houser has two dogs, a cat, and a Chinese water dragon at home.  She enjoys reading, hiking, playing video games, and occasionally brewing beer.  She hopes to work with pet birds and exotics once she graduates, as well as volunteer with local wildlife centers.

“I first became more interested in birds during [my undergraduate degree] at University of Oregon when I volunteered at the Cascades Raptor Center in Eugene,” she said. “For the past two years I have been volunteering at Chintimini Wildlife Center in Corvallis. I think birds are such fascinating creatures, and I would like to stay involved with wildlife conservation efforts.”


Ashley Mooney

Ashley Mooney, writer for GPAP

Ashley Mooney is a veterinary student at the University of Melbourne and an aspiring avian specialist.  She has been assisting the Grey Parrot Anatomy Project by liaising with researchers and writing promotional briefs for the Project’s website.

While birds are her primary passion, she has sought experiences with primates through the Jane Goodall Research Institute, where she did research on chimpanzee behavior.  She has also worked as a science writer since 2010, first as a writer and editor for Duke University’s student newspaper, and now as a freelance editor.

Mooney is grateful for the opportunity to work with so many esteemed veterinarians and researchers through the Project, and is excited to contribute more to the field once she graduates.


Dr. Sarah Nemanic

Dr. Sarah Nemanic

Dr. Sarah Nemanic is an assistant professor of radiology at Oregon State University.  Prior to attending veterinary school, Nemanic earned a master’s and Ph.D. in neuroscience in the field of learning and memory at the University of Texas, Houston Health Science Center.  She has been a board-certified radiologist since 2011.

Nemanic is currently working on an interactive online resource for teaching normal radiographic anatomy to veterinary students.  The project initially focused on dogs, cats, and horses, but has since expanded to include avian species. Veterinary student Jackie Houser and computer scientist Matt Viehdorfer are both assisting with the project.

“Creating the normal radiographic anatomy software application is a fusion of my interests in learning and memory and veterinary radiology,” she said. “We did an experiment testing the efficacy of this program on the dog radiographic anatomy and found that it was highly effective.  This will be in an upcoming issue of the Journal of Veterinary Medical Education.”

Nemanic’s other research interests include methods of diagnosing orthopedic diseases in dogs and staging of canine and feline oncology patients.


Dr Emma Schachner

Dr Emma Schachner- contributor, grey parrot respiratory system

Dr Emma Schachner- contributor, grey parrot respiratory system

Emma Schachner, an Assistant Professor in the Department of Cell Biology and Anatomy at Louisiana State University Health Sciences Center, has been collaborating with the Grey Parrot Anatomy Project since her days as a post-doctoral researcher.  Schachner’s primary focus is on the evolution of reptile and bird lungs. As a paleontologist and evolutionary anatomist by training, Schachner looks at modern relatives of dinosaurs to reconstruct their respiratory anatomy. With over 150 scans of several species, Schachner is working on qualitative descriptions of the air sacs, lungs, and other branches of their respiratory tracts.  When working with engineers, Schachner is even able to visualize airflow patterns or transform her CT data into 3D-printed models.

“I’m interested in form and function, like why is something shaped the way it is and why it evolved to be that way,” Schachner said. “Every bird that I do a model of provides an exciting surprise to see how it’s going to turn out.”

Although Schachner’s research is broad in its nature, she said she prioritizes her studies on the grey parrot.  Because of the Grey Parrot Anatomy Project, Schachner is able to utilize larger sample sizes (N = 9 birds) to overcome the challenges presented by individual variation, and create a more comprehensive view of the species’ respiratory anatomy.  Additionally, the quality and power of the micro CT imaging allows her to build even more accurate high resolution models.

Eventually, Schachner hopes to scan a kiwi bird, which according to a publication from the 19th century, does not have an abdominal air sac like other birds.  She also said she would love to image a hoatzin, a pheasant-like bird from South America. Hoatzin juveniles possess claws on their thumb and first finger, allowing them to climb trees. Schachner said that some of the genetic mechanisms that control limb development are linked to lung development, and she is curious as to how much the hoatzin respiratory tract differs from other birds.

For more details on Dr Schachner, go to her website


Dr Nico Schoemaker and Dr Yvonne van Zeeland 

Dr Nico Schoemaker

Dr Nico Schoemaker

Dr Yvonne van Zeeland

Dr Yvonne van Zeeland

Dr. Yvonne van Zeeland and Dr. Nico Schoemaker from Utrecht University are working to unravel the mysteries of the neuroanatomy and neurophysiology of the African grey parrot.

Although a basic understanding of the avian brain has been established, there currently is relatively little information on brain pathology and functional linking of brain regions in birds. By using micro-MRI and Diffusion Tensor Imaging (DTI), Yvonne and Nico hope to elucidate neural pathways between different brain regions.

“This research will help to gain further detailed knowledge of the normal avian brain, following which comparison of healthy with abnormal brains may take place to help gain a better understanding of brain diseases in birds, and how these may be dealt with,” she said.

Eventually, Yvonne and Nico also hope to apply their findings to prevent and treat behavior issues such as feather damaging. This behavior problem is particularly common in grey parrots and cockatoos, with a reported prevalence of up to 40 percent.

“We are hypothesizing that this type of abnormal repetitive behavior is similar to compulsive/impulsive behaviors where there is a lack of inhibition from the centers that regulate and control the initiation of behaviors,” she said.

As a consequence of this lack of inhibition, birds may not be able to control urges to damage feathers, which may particularly be true in chronic cases. DTI may allow the researchers to visualize functional differences in the brains of birds that are expressing these behaviors versus healthy individuals and also allow comparison with those that exhibit stereotypic behaviors, which they hypothesize to be controlled by different brain regions.

Beyond their research on neuroanatomy, Nico and Yvonne are also studying the influence of the parrot’s personality and living environment on the likelihood of a bird developing feather damaging behavior. As part of this project, an online survey has been prepared for owners to fill out information regarding their bird, its behavior and living environment.

“With the help of the information derived from this and other studies, we hope to gain insight in how to tailor environmental and social enrichment to an individual parrot’s behavioral needs, thereby hopefully also preventing behavior problems such as feather damaging behavior,” she said.

More information about the studies conducted in Utrecht is available on the Utrecht University webpage.


Dr Brian Speer

Dr Brian Speer

Dr Brian Speer

A pioneer of modern avian medicine, Dr. Brian Speer has worked with both the Grey Parrot Anatomy Project and the Radiograph Based Density Study since their inception. His research focuses on enhancing the understanding of avian skull anatomy, muscular anatomy, kinesiology, and their applications to clinical practice.

“In reality, it was this original interest that sparked Scott (Echols) and my exploration into the types of CT imagery that was available, and got us started on the road to where the project has headed today,” Speer said.

Speer’s findings have allowed the researchers to balance prokinetic function, keratin form, and wear, with myology and functional kinesiology.  This has improved his approach to complicated clinical issues of the beak, such as treating lateral beak deviations in large macaw species, prognathism in cockatoos, and keratin overgrowth issues.

“Probably the largest change in our thought processes that has come from our research paired with dissections is the ability to balance prokinetic function, keratin form and wear, with myology and functional kinesiology as we work to correct the problems that we see,” he said. “The fascinatingly complex nature of prokinetic and coupled kinetic function has actually become more dynamically interactive and clear.”

As part of the density project, Speer has also been taking HD CT images of patients and specimens at his clinic, The Medical Center for Birds, in Oakley, California.

“The nature of my work is predominantly clinical practice, although I teach regularly at my alma mater, the [University of California Davis], and I am an author,” Speer said. “That of course, is balanced with trying to be a good dad, and husband to my best friend in life, Denise.”

Speer’s most recent publication is Current Veterinary Therapy in Avian Medicine and Surgery.


Dr Henry Tsai

Dr Henry Tsai

Dr Henry Tsai, joint and limb anatomy GPAP

Dr. Henry Tsai  is a postdoctoral researcher at Brown University in the department of Ecology and Evolutionary Biology.  Tsai studies the evolution of locomotion in archosaurs—crocodilians, birds, and extinct forms like dinosaurs.  His research focuses on combining anatomical, histological, and imaging techniques to reconstruct joints of extinct archosaurs and to understand how their morphology relates to their evolutionary history.)

“Ultimately, I seek to understand the mechanical functions, kinematics, and developmental significance of vertebrate appendicular joints, as well as how joint functional morphology relates to behavior, performances, and ecology of archosaurs throughout their remarkably diverse evolutionary history, including the largest animal ever to walk on earth,” he said.

Tsai recently took part in the Austin Working Group for advancing contrast-enhanced CT imaging in the biological sciences, where he co-authored a publication that provides a comprehensive synthesis on iodine-based staining and imaging protocols.