Using X-rays to learn what walking rats can teach us about early placental mammal locomotion

In paleontology, we often infer the habits and behaviors of fossil vertebrates by reference to their skeletal shape. However, it is often difficult to appreciate what those shapes are telling us: how well does shape correlate with motion?

We are members of the eutheiran branch of the mammal family tree. Among many questions concerning mammal evolution, one is how did the earliest eutherian (so-called “placental”) mammals use their forelimbs? This question has important implications for how our earliest relatives got around. The earilest known members of our group are small and are often hypothesized to be scansorial (Luo et al., 2003, 2011), meaning that they are at home on the ground as well as clambering up trees.These inferences are drawn in large part from the form of the fossilized forelimb bones and their presumed functions.

If you’ve been following this blog, you know that I have been immersed in learning XROMM (X-ray Reconstruction of Moving Morphology), a technique that combines video fluoroscopy (X-ray movies) with registration of three-dimensional bone models to yield 3-D moving X-rays.

I am happy to report that my colleagues, two Stockton undergraduates (Radha Varadharajan and Corey Gilbert), and I have published an Open Access article in PLoS One that, for the very first time, reconstructs the three-dimensional movements of the long bones (humerus, radius, ulna) in the forelimb of rats. Why rats? Rats have a forelimb anatomy that is very similar in many ways to those of the earliest eutherian mammals, and as a plus, rats are scansorial. Rats are also relatively easy mammals to work with in the lab (although some days they out-clever the humans) and can be trained. As a fun side note, we named two of the rats Pink and Floyd.

Our setup was straightforward — at the C-arms XROMM lab at Brown University, the rats walked along a plank of wood to a darkened hide box. While traversing the plank, they made their X-ray cameos in two fluoroscopes connected to hi-speed cameras filming at 250 frames per second (your iPhone camera films at 30 frames per second in normal mode). When we were finished collecting our data, the rats were CT-scanned so that we could have exact three-dimensional models of their limb bones. The most painstaking part was the several months it took to digitize each of our good trials. That is, using animation software, we had to match the bone models up to their X-ray shadows in the two calibrated fluoroscope movies. Once this was accomplished, our task turned to watching how the bones moved in three-dimensional space as well as analyzing the joint angle data that was generated.

Our basic setup for the XROMM study -- rats were trained to walk across a plank towards a dark hide box, leading them between the two videofluoroscopes.

Our basic setup for the XROMM study — rats were trained to walk across a plank towards a dark hide box, leading them between the two videofluoroscopes.

What we found both confirms previous work on small mammal locomotion, but added some interesting new insights as well. As a general rule, small mammals have a crouched posture where the elbows and knees are bent. This type of posture may aid small mammals in maneuvering around objects and keeping a lower center of gravity, which would enhance stability, especially on branches and other narrow perches. Not surprisingly and given previous work on rat locomotion, we see that these mammals do indeed walk on crouched limbs — the elbow angle, for example, never exceeded 123 degrees in full extension. By way of comparison, your elbow can be extended to 180 degrees.

A figure from my book, The Bare Bones. Note how the rat has a more crouched posture whereas the cat is more upright.

A figure from my book, The Bare Bones. Note how the rat has a more crouched posture whereas the cat is more upright.

However, we often get the impression that mammal locomotion is similar at different scales. From cats and dogs on up, it appears that the forelimbs and hindlimbs function very much as glorified pendulums. In essence, eutherian mammal locomotion is understood as mostly two-dimensional. Although rats are small and have a crouched posture, their limb bones would be presumed to follow the pendulum model.

But what the bones were doing in three-dimensions was fascinating. Both the humerus (upper arm bone) and radius (the forearm bone that aligns with your thumb) showed they were capable of long-axis rotation. Long-axis rotation is similar to the way a lathe or axle spins. Our rats’ bones certainly weren’t spinning on their long-axis, but they did show a non-trivial range of movement. A step cycle consists of a stance phase (when the hand is on the ground and forelimb is supporting the body) and a swing phase (when the hand is off the ground and the forelimb is swinging back to support the body for the next step). We found that during stance, the humerus both moves toward the midline (adducts) and rotates on its long axis towards the body. These combined movements appear to ensure that the elbow points backwards so that the forearm maintains an upright posture. During swing, the humerus moves away from the body midline (abducts) and rotates on its long axis away from the body. These combined movements seem to allow the forelimb to clear the rat’s body as the limb is brought forward to start a new step.

Lateral, ventral, and radioulnar joint views of the humerus (sea green), radius (black), and ulna (red) in a typical step cycle in Rattus norvegicus. Long-axis rotation (LAR) of the radius about the ulna (radius pronation) is shown in cranial view from the perspective of the ulna (the ulna appears to be stationary in the radioulnar joint view relative to the humerus and radius). Note radius (black) LAR relative to the ulna (red). Percentages = portion of the step cycle. Black bar in ventral view = body midline based on sternum.

Lateral (side), ventral (belly), and radioulnar joint (at the elbow) views of the humerus (sea green), radius (black), and ulna (red) in a typical step cycle in Rattus norvegicus. Long-axis rotation (LAR) of the radius about the ulna (radius pronation) is shown in cranial view (the rat is walking toward you) from the perspective of the ulna (the ulna appears to be stationary in the radioulnar joint view relative to the humerus and radius). Note radius (black) LAR relative to the ulna (red). Percentages = portion of the step cycle. Black bar in ventral view = body midline based on sternum.

MOVIE 1 – All the rats walking betwixt the fluoroscopes with their CT-scanned bones registered to the frames.

MOVIE 2 – One of our rats, “Floyd,” demonstrating a typical step cycle.

What was particularly exciting to me was that we saw, for the first time in rats, the radius pivot about the ulna! In humans, we take these movements for granted: our radius pivots around our ulna with ease, directing our palms either downward (pronated) when its shaft cross over the ulna, or upward (supinated) when its shaft rotates into parallel with the ulna. Up until now, it has been unclear if the radius could move in this way to flip the hand palm-side down in rats, or whether their hand posture was maintained via positioning of the limb in general. We now know that, indeed, the radius does move and does appear to be correlated with hand placement in rats. These movements are much more subtle than in you and I (in our rats a range of 10-30 degrees of rotation), but they appear to be correlated with pronation of the hand.

MOVIE 3 – One of our rats, “Floyd,” showing how the radius pivots on the ulna during a step cycle.

Our research has two messages. The first message is that given the similarities in the forelimb skeletons of the earliest known eutherian mammals (Juramaia and Eomaia) to those of rats, it is likely that a similar range of movements were possible in these distant relatives on our family tree. Paleontologists studying these fossils, such as Zhe-Xi Luo and colleagues (Luo et al., 2003, 2011), have already suggested these early eutherian mammals were scansorial, and our data bolster their hypothesis. These sorts of insights are helpful in constraining when particular locomotor behaviors and movements became possible and how that might have effected mammalian evolution.

The second message is that small mammal locomotion is probably not as similar to those of larger mammals as we often think, a sentiment echoed by the late Farish Jenkins (e.g., Jenkins, 1971) and by Martin Fischer and his colleagues (Fischer et al. 2002; Fisher and Blickman, 2006). Moreover, our rat data show that, at least for the forelimb, long-axis rotation plays a role in normal overground movement.

We hope our study provides another perspective on small mammal locomotion and encourages new and fruitful research in our furry friends past and present.

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I am grateful to my colleagues and former students for their help and work on this project. I want especially to thank Elizabeth Brainerd (Brown University). She has been a source of encouragement and a patient teacher to an old dinosaur learning new tricks, and her help with learning XROMM and on designing the experiment which led to this paper (my first foray into animal kinematics) was invaluable.

The authors of the paper (* indicates a Stockton University undergraduate)

Matthew F. Bonnan (Stockton University, Biology)
Jason Shulman (Stockton University, Physics)
*Radha Varadharajan (Stockton University, Biology)
*Corey Gilbert (Stockton University, Physics)
Mary Wilkes (Stockton University, Biology)
Angela Horner (California State University, San Berardino)
Elizabeth Brainerd (Brown University)

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References

Fischer, M. S., and R. Blickhan. 2006. The tri-segmented limbs of therian mammals: kinematics, dynamics, and self-stabilization—a review. Journal of Experimental Zoology Part A: Comparative Experimental Biology 305A:935–952.

Fischer, M. S., N. Schilling, M. Schmidt, D. Haarhaus, and H. Witte. 2002. Basic limb kinematics of small therian mammals. The Journal of Experimental Biology 205:1315–38.

Jenkins, F. A. 1971. Limb posture and locomotion in the Virginia opossum (Didelphis marsupalis) and in other non-cursorial mammals. Journal of Zoology, London 165:303–315.

Luo, Z.-X., Q. Ji, J. R. Wible, and C.-X. Yuan. 2003. An Early Cretaceous Tribosphenic Mammal and Metatherian Evolution. Science 302:1934–1940.

Luo, Z.-X., C.-X. Yuan, Q.-J. Meng, and Q. Ji. 2011. A Jurassic eutherian mammal and divergence of marsupials and placentals. Nature 476:442–445.

Bearded Dragon Runs for Science!

Bonnan Lab Lizard TreadmillA brief post to show our progress in the BFF Locomotion Lab. We’re learning our equipment and training our lizards to walk and run. The lizards are rewarded with a cricket as a treat. The lizard you see in the video is Graybeard, a juvenile bearded dragon (Pogona vitticeps). This video is comprised of two synched cameras and is a test video and not yet the “real” thing. But we’ll be capturing real data and more soon enough.

As always, stayed tuned and there will be more reptiles running in the near future!

It is official: the BFF Lab has a CT scanner

It was an exciting day for the BFF Lab — we installed and operated our Animage FIDEX CT scanner for the first time!  We selected a preserved specimen of a mudpuppy salamander (Necturus) to anoint our system.  You can see the animation below of the anterior half of the salamander’s skeleton.

Why are there large gaps between the bones of the arms, you ask?  Salamanders like the mudpuppy have thick, cartilaginous joints.  Cartilage does not typically show up in X-rays, and hence the “gaps.”

The XROMM lab at Richard Stockton University is coming together piece by piece.

We are forever grateful to lab director Justine Ciraolo and our NAMS shop director William Harron for so much help in obtaining and coordinating our receipt of this equipment.  We also want to give a big shout out to Stephen Della Ratta of Animage for his help, enthusiasm, and expertise in setting up our CT scanner.  Our training on the FIDEX scanner was thorough and friendly, and all our questions were answered.  Thank you, Stephen.

Stay tuned for more exciting news in the near future …

XROMM is coming to Stockton and the BFF Lab!

This has been working its way through the pipeline for quite awhile, but I can finally, confidently announce that the Richard Stockton College of New Jersey will house the first XROMM lab specifically focused on undergraduate research and teaching!

XROMM (X-ray Reconstruction of Moving Morphology) is a state-of-the-art technique, developed at Brown University, for visualizing rapid skeletal movement in vivo in three-dimensions.  Find out more here and here.

Harry, one of the rats in our trials, walking through the X-ray beams.

Harry, one of the rats in our trials, walking through the X-ray beams.

This tremendously exciting development resulted as part of a large state grant and is part of Stockton’s growing science infrastructure.  We have a second new science building on the way that will house a beautiful new vivarium and will have a custom-built XROMM lab.

The equipment we will be receiving will include hi-speed videofluoroscopes (layman’s terms: super science cool X-ray movie cameras) and a veterinary CT-scanner.

To say this is a dream come true is probably an understatement!  What it means is that we will soon have the ability to reconstruct three-dimensional moving skeletons of vertebrates for research that directly involves undergraduates.  Stay tuned to this blog and the BFF lab, and we’ll keep you posted on this exciting new development for our students and college.  My co-conspirator (eh, collaborator) Jason Shulman and I are ecstatic.

In the meantime, there are many, many people to thank.  First, Beth Brainerd, Stephen Gatesy, and the other XROMM gurus at Brown University granted me the opportunity to learn this technique through their NSF-sponsored short course.  Among the many people who have helped me understand and develop my familiarity with XROMM are David Baier and Ariel Camp, who have answered a myriad of questions.  Beth Brainerd was instrumental in this process from helping me capture my first data for analysis with Stockton undergraduate Radha Varadharajan to her generous time and assistance in understanding the specs of such a lab.  Thank you, Beth!  Angela Horner (now at California State University San Bernardino) was also instrumental in collecting our initial rat data at Brown and helping us understand how rats “tick.”

For both Jason and I, we are grateful for the on-going support and encouragement of our peers and staff at Stockton.  During the past two years, lab director Justine Ciraolo and safety officer Bob Chitren have been incredibly helpful and encouraging, and it would have been impossible to get this done without their help.  Jason and I are grateful for the support of the school of Natural Sciences and Mathematics (NAMS), to Dean Weiss, to Provost Kesselman, and President Saatkamp for supporting cutting-edge science at our college.  We are also thankful for the support and encouragement we have received from our programs, Biology and Physics, and from the generous support of the Provost and Grants Office for internal grants that have placed us in this exciting position.

We must make a special mention of John Rokita and the animal lab staff for keeping our animals happy and healthy, and the Institutional Animal Care and Usage Committee (IACUC) here at Stockton for overseeing our animal research.  Again, the NAMS laboratory staff are to be thanked for all of their continuing help in making such exciting STEM experiences possible for our students.

Finally, Jason and I are delighted that we can bring this caliber of research to our students at Stockton.  It will allow us to expand on our locomotion research using optical tracking, and give students pursuing a wide range of careers in the sciences a rare opportunity to learn about the living skeleton in action.  Most importantly, the XROMM lab will expand Stockton’s already strong history of producing New Jersey STEM majors.

We will blog and tweet about the progress of the XROMM lab setup and keep you informed about how it is all coming together over the next several months.  Stay tuned!

Leaping lizards and running rats

Given the positive feedback and interest in our POV of a ferret running on a treadmill, we’ve upped the ante here at the Best Feet Forward lab.  We proudly present two more GoPro POV movies of our magnificent animals running for science.  Would you like to see a running Bearded Dragon (Pogona vitticeps) and lab rat (Rattus norvegicus)?  Of course you would.

Above you see Greenbeard running for science.  We’re shaking a tasty bucket of crickets off-camera to get him to run.

Above you see one of our lab rats, Frank, also running for science.  If you look closely you can see the reflective beads attached to him that we follow with the infrared OptiTrack camera system.

Bridget Kuhlman is once again thanked for her brilliant camera work.

Why do we do what we do?

The BFF Lab Students and Faculty in the Spotlight!

Black Beard the Bearded dragon,

Black Beard the Bearded dragon. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

I am excited to report that the Best Feet Forward (BFF) Lab has had its first local news story! Susan Allen at the Office of News & Media Relations at Stockton College has written a wonderful article that was distributed to the associated press today.  We thank Susan for this wonderful story, which we reproduce here in this post (see below).  All photos are copyright Susan Allen / The Richard Stockton College of New Jersey.

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Stockton College Researchers Analyze Locomotion of Modern Day Reptiles, Mammals to Understand How Dinosaurs Moved

By Susan Allen, Office of News & Media Relations, Richard Stockton College of New Jersey

Galloway Township, NJ- Caleb Bayewu, a junior Biochemistry major, cradled a bearded dragon in his hands as Cory Barnes, a senior Biology major, attached tiny reflective beads to the bumpy skin on the patient reptile’s forearm.

Caleb Bayewu, a junior Biochemistry major (left), cradled a bearded dragon in his hands as Cory Barnes (right), a senior Biology major, attached tiny reflective beads to the bumpy skin on the patient reptile’s forearm.

Caleb Bayewu, a junior Biochemistry major (left), cradled a bearded dragon in his hands as Cory Barnes (right), a senior Biology major, attached tiny reflective beads to the bumpy skin on the patient reptile’s forearm. Photo (c) Susan Allen / The Richard Stockton College of New Jersey

Black Beard, as the lizard is nicknamed, is one of three juvenile bearded dragons at The Richard Stockton College of New Jersey taking part in an animal locomotion research project aimed at better understanding how dinosaurs once moved across our planet.

After body measurements were recorded, Black Beard was placed on a treadmill surrounded by a system of three infrared cameras and plastic containers that serve as safety nets in case a reptile runner strays off course.

As soon as Bayewu shook a clear jar of jumping crickets, Black Beard sprang into action. Alex Lauffer, a junior Biology major, flipped the conveyor belt switch, the treadmill kicked on and the cameras began transmitting data to Dr. Matthew Bonnan, associate professor of Biology, and Dr. Jason Shulman, assistant professor of Physics.

Caleb Bayewu, a junior Biochemistry major from Maywood in Bergen County, shakes a jar of jumping crickets to motivate a beaded dragon to run on the treadmill. From the left, Alex Hilbmann, a sophomore Biology major from West Deptford in Gloucester County, Alex Hilbmann, a sophomore Biology major from West Deptford in Gloucester County, and Corey Barnes, a senior Biology major from Seaville in Cape May County, stand by.

Caleb Bayewu, a junior Biochemistry major from Maywood in Bergen County, shakes a jar of jumping crickets to motivate a beaded dragon to run on the treadmill. From the left, Alex Hilbmann, a sophomore Biology major from West Deptford in Gloucester County, Alex Hilbmann, a sophomore Biology major from West Deptford in Gloucester County, and Corey Barnes, a senior Biology major from Seaville in Cape May County, stand by.  Photo (c) Susan Allen / The Richard Stockton College of New Jersey

Sophomore Biology majors Kieran Tracey and Alex Hilbmann stood close by, making sure Black Beard stayed on the treadmill.

Kieran Tracey, a sophomore Biology major from Sea Isle City in Cape May County, guides a beaded dragon to the treadmill as Caleb Bayewu, a junior Biochemistry major from Maywood in Bergen County, holds a jar of crickets. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

Kieran Tracey, a sophomore Biology major from Sea Isle City in Cape May County, guides a beaded dragon to the treadmill as Caleb Bayewu, a junior Biochemistry major from Maywood in Bergen County, holds a jar of crickets. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

While Black Beard ran in place, the cameras captured the motion of each reflective bead sending real experimental data at the overwhelming rate of 120 frames-per-second to a computer program that can read and display the data as moving dots.

From behind their monitor, Bonnan, of Hammonton, and Shulman, of Egg Harbor Township, watched each step on their screen.

Dr. Matthew Bonnan, associate professor of Biology, and Dr. Jason Shulman, assistant professor of Physics, are working together with students to model dinosaur movement by studying modern day reptiles and mammals. “Given that the earliest mammals and dinosaurs had a forelimb posture not unlike lizards, they are acting as a model to test hypotheses about the transition from sprawling to upright forelimb postures,” said Bonnan. Shulman has been instrumental in analyzing the data, which is captured at 120 frames-per-second by a system of infrared cameras. “He is a big part of why we're able to do this. Without him, interpreting the data would be difficult at best,” said Bonnan. (c) Photo: Susan Allen/ The Richard Stockton College of New Jersey

Dr. Matthew Bonnan, associate professor of Biology, and Dr. Jason Shulman, assistant professor of Physics, are working together with students to model dinosaur movement by studying modern day reptiles and mammals. “Given that the earliest mammals and dinosaurs had a forelimb posture not unlike lizards, they are acting as a model to test hypotheses about the transition from sprawling to upright forelimb postures,” said Bonnan. Shulman has been instrumental in analyzing the data, which is captured at 120 frames-per-second by a system of infrared cameras. “He is a big part of why we’re able to do this. Without him, interpreting the data would be difficult at best,” said Bonnan. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

Stepping Back in Time

“Without a time machine, we can’t put dinosaurs on a treadmill,” said Bonnan, who has been fascinated with dinosaurs since he was 5 years old. Instead, bearded dragons, ferrets, rats and a Savannah monitor are “standing in for their ancestors” at the Best Foot Forward (BFF) Laboratory on the main Galloway, NJ campus.

Bridget Kuhlman, a senior Biology major, of Little Egg Harbor in Ocean County, left, and Kelsey Gamble, a senior Anthropology and Biology major, of Williamstown in Gloucester County, were in the Best Foot Forward Laboratory to gather data on ferret movement patterns. Kuhlman, said, “It’s a dream come true being able to work with ferrets. It’s getting me ready for vet school,” she said. She works as an EMT and personally owns five ferrets. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

Bridget Kuhlman (left), a senior Biology major, of Little Egg Harbor in Ocean County, left, and Kelsey Gamble (right), a senior Anthropology and Biology major, of Williamstown in Gloucester County, were in the Best Foot Forward Laboratory to gather data on ferret movement patterns. Kuhlman, said, “It’s a dream come true being able to work with ferrets. It’s getting me ready for vet school,” she said. She works as an EMT and personally owns five ferrets. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

“Given that the earliest mammals and dinosaurs had a forelimb posture not unlike lizards, they are acting as a model to test hypotheses about the transition from sprawling to upright forelimb postures,” said Bonnan.

The fossil record offers scientists a motionless slice of history. Bonnan and his team have turned to optical tracking technology to tell more of the story.

“Our ultimate goal is to realistically model and place constraints on how fossil vertebrates, such as dinosaurs and early mammals, moved their forelimbs,” Bonnan explained.

The team is quantitatively illustrating the motion of modern day reptiles and mammals and using bone shape as a common denominator to make comparisons between their laboratory stand-ins and dinosaurs.

Bonnan’s lifelong desire has been to “reconstruct long-dead animals and breathe life into old bones.”

Step-by-step, his vision is coming to life with the support of colleagues, student researchers and staff within the School of Natural Sciences and Mathematics.

Blending Physics and Biology

To model motion, math and physics come into play. Bonnan’s friend and colleague, Dr. Jason Shulman, joined the team lending his numerical analysis expertise. “Jason Shulman is a big part of why we’re able to do this. Without him, interpreting the data would be difficult at best,” said Bonnan.

Early in the Physics curriculum, students learn to calculate angles and speed, which means that undergraduates are prepared to take part in real research outside of textbook exercises Shulman said.

Sometimes Physics majors wonder why they need to study Biology and vice versa. The animal locomotion research is an example of how the sciences work together. “It’s important for students to understand concepts outside of their field—that’s an important lesson I hope we convey.

The interdisciplinary collaboration is perfect for Physics students,” said Shulman.

Campus-wide Support

The bearded dragons were donated to Bonnan by student Kiersten Stukowski, of Gloucester in Camden County. Scientists rarely have the opportunity to work on a long-term project with the same specimens as they mature explained Bonnan.

Justine Ciraolo, director of Academic Laboratories and Field Facilities, connected Bonnan with her sister, who is loaning her ferrets to the team.

One of our ferrets, "Mocha."

One of our ferrets, “Mocha.” Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

When the reptiles and mammals aren’t in the lab, they are cared for by John Rokita, principal animal health lab technician, who has been instrumental in acquiring specimens for Bonnan.

“None of this would have been possible without the support of the School of Natural Sciences and Mathematics and Stockton’s Institutional Animal Care and Usage Committee. It is rare for undergraduates to get this experience. On every level this is teamwork and everyone has been incredibly helpful,” said Bonnan.

The Student Researchers

Alex Hilbmann, a sophomore Biology major, of West Deptford in Gloucester County, says he’s learned all about lizards while building a foundation to better understand the kinematics (or science of motion) during his independent study. “It wasn’t always easy to get them to run,” he admitted. Hilbmann plans to go on to medical school after Stockton.

Caleb Bayewu, a junior Biochemistry major who’s from Maywood in Bergen County, started out working with rats on the treadmill, but “they didn’t always want to move.” Since he joined the team, he’s witnessed the differences in movement among different species.

Corey Barnes, a senior Biology major, of Seaville in Cape May County, took Comparative Anatomy with Dr. Bonnan, which he says opened up his interest along the evolutionary tree. The research has really illustrated “how different their walking habits are.” Barnes is a veterinary technician at Beach Buddies Animal Hospital in Marmora and hopes to attend veterinary school.

Alex Lauffer, a junior Biology major, of Point Pleasant in Ocean County, has always had an interest in dinosaurs and reptiles. The research project was “right up my alley,” he said. The aspiring veterinary assistant has three snakes, one tarantula, one dog and a pond of koi fish. However, it was in the BFF Lab that he held his first bearded dragon. They are surprisingly calm, he said.

Kieran Tracey, a sophomore Biology major, of Sea Isle City in Cape May County, said, “I’m having a lot of fun working with lizards and watching them run,” and added that the experience is giving him important exposure to research in preparation for medical school. He looks forward to “analyzing how [the data] relates to dinosaurs.”

Bridget Kuhlman, a senior Biology major, of Little Egg Harbor in Ocean County, said, “It’s a dream come true being able to work with ferrets. It’s getting me ready for vet school,” she said. She works as an EMT and personally owns five ferrets.

Bridget Kuhlman (left) and Kelsey Gamble (right) attach tracking beads to the ferret nick-named, "Mocha" as Drs. Bonnan and Shulman look on.

Bridget Kuhlman (left) and Kelsey Gamble (right) attach tracking beads to the ferret nick-named, “Mocha” as Drs. Bonnan and Shulman look on. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

Kelsey Gamble, a senior Anthropology and Biology major, of Williamstown in Gloucester County, said, “Working with live animals is an interesting experience. It’s a lot different than my anthropology work,” she said. “We are looking at the forelimbs and how they move.” The search for patterns and constructing relationships between form and function blend her Biology and Anthropology interests.

Kelsey Gamble, a senior Anthropology and Biology major, of Williamstown in Gloucester County, said, “Working with live animals is an interesting experience. It’s a lot different than my anthropology work,” she said. “We are looking at the forelimbs and how they move.” The search for patterns and constructing relationships between form and function blend her Biology and Anthropology interests. Pictured, she holds a ferret that is taking part in the animal locomotion research project at Stockton College. Photo (c)

Kelsey Gamble, a senior Anthropology and Biology major, of Williamstown in Gloucester County, said, “Working with live animals is an interesting experience. It’s a lot different than my anthropology work,” she said. “We are looking at the forelimbs and how they move.” The search for patterns and constructing relationships between form and function blend her Biology and Anthropology interests. Pictured, she holds a ferret that is taking part in the animal locomotion research project at Stockton College. Photo (c) Susan Allen/ The Richard Stockton College of New Jersey

Contact:         Susan Allen
                        Office of News & Media Relations
                        Galloway Township, NJ 08205
                        Susan.Allen@stockton.edu
                        (609) 652-4790

Ferret on a treadmill — you read that correctly

When you’re interested in documenting forelimb locomotion to help you infer what was going on extinct reptiles and mammals, it pays not to be picky.  So when the opportunity came to analyze the gaits of two ferrets materialized, how could the BFF lab say no?  Ferrets have a unique body morphology and certainly have a much more upright forelimb than the rats and reptiles we typically work with, so they help form a nice point of contrast and comparison.

What happens when you place a GoPro camera at the end of the treadmill?  Success, that’s what.  BFF student Bridget Kuhlman did just that the other week in our lab during our data capture sessions, and she got this brilliant bit of POV video.  You don’t see Bridget directly in the video, although you do see her finger which has a tasty smear of FerretVite which we use to coax the ferrets to walk in the line of the infrared cameras.  In the background, modulating the treadmill, is BFF student Kelsey Gamble.

You will notice that this Ferret, nick-named “Latte,” walks and then rides the treadmill backwards, then walks again.  Science is messy — no animal is going to walk in perfect rhythm with the treadmill from start to stop.  What we do is capture all the data, and then find the motion capture portions where “Latte” and our other animals are keeping pace with the treadmill.  Incidentally, we measure various body dimensions on the animals each session (in case they grow or put on/lose weight) and we note the treadmill speed so we can calculate how fast they are moving.

“Latte,” and his room-mate “Mocha,” have been temporarily loaned to us thanks to the generosity of Jen Ciraolo.