By Kate Garland, PhD student, Fulbright Postgraduate Scholar, (MEME) Erasmus Mundus Master Programme in Evolutionary Biology
“Be like the bird who, pausing in her flight
awhile on boughs too slight,
feels them give way beneath her, and yet sings,
knowing she has wings.”
Victor Hugo
This quote felt very apt to start the write-up on my conversation with the wonderful Dr. Ashley Heers. Not only is it fitting because Ashley’s research centers on understanding the evolution and developmental story behind the adaption of flight in birds. But also, during my conversation with Ashley, we touched on a very important aspect of life as a scientist. That despite obstacles in your career, it is self-belief and hard work that keep us going – if you will – it is always knowing we have wings.
Ashley spoke to me over Zoom from her home in Southern California. She was accompanied by her two cats, who occasionally stole the show, brushing past her or scampering off to steal some popcorn from the cupboard. In the background, outside, you also could catch a glimpse of Ashley’s ducks running across the pen. These ducks were past participants of her behavioral experiments and now live a life of luxury, dining on their favorite snacks, mealworms and peas.
It was clear to me that Ashley loves animals. But her journey to studying animals stemmed from a passion for learning itself. “I’ve always loved learning,” said Ashley, “I got particularly interested in science when I started doing Science Olympiad.” In Science Olympiad, Ashley participated in the Rocks and Minerals events, where she learned to identify rocks, minerals and occasionally fossils. It was there that Ashley says she becameparticularly interested in science, especially in geology and paleontology, and that interest continued through high school.
Ashley acknowledged her teachers who set her on this path, saying, “I grew up in a really small town, and I got really lucky to have really good teachers. (…) In terms of science, it was probably two teachers in my formative years that had a really big impact. My 7th and 8th grade science teacher, who was also the Science Olympiad coach, was the one who really got me hooked. (…) Then, in high school, my cross-country coach, of all things, was also one of the science teachers there (…) He was just always really enthusiastic about science in general, and his subject area was biology.”
But when Ashley got to college and started to pick out her majors, she realized her main interest in geology focused on asking why we saw changes in the fossil record over these long periods of time. Ashley explained, “During our summer orientation, before we even started school, when I looked at the catalogue of courses, I thought, ‘Oh, wow, some of the classes I want to take are in geology. But all of the evolution classes and mechanisms behind these changes are in biology.’ So I ended up double majoring in geology and biology.”
During college, Ashley did a senior project investigating whether the center of mass in birds is a good predictor of their wing and leg proportions. If so, it would enable you to extrapolate backwards to fossil taxa and give insights into the locomotor potential of birds’ extinct ancestors, the dinosaurs. The project was a catalyst for Ashley to discover her passion for studying bird locomotion. “I had this sort of epiphany,” Ashley said, “where I thought, ‘The origin of birds and the evolution of flight – that sounds like a really cool topic. Maybe that’s what I want to study.’ I realized that if I wanted to study how flight evolved, I had a problem because I knew nothing about living birds or how they fly. And so I did a complete 180. When I was applying for grad schools, I threw in some biology departments as well because I figured I needed to learn about birds before I started studying their history. And so the first place I interviewed at was the University of Montana, and I fell in love with it.”
When discussing her research ideas with soon-to-be PhD supervisor, Professor Ken Dial at the University of Montana, Ashley said she “didn’t realize that developmental transformations could be nearly just as dramatic as some of the ones that you see in the fossil record, and you get to see them in real-time.”
And so began Ashley’s path to making incredible findings about bird flight from a developmental and evolutionary perspective. Ashley’s research into how baby birds move and begin to fly is essential to gaining a better understanding of the animal’s locomotion behaviors and abilities in general. Furthermore, it provides important insight into the possible process by which flight may have evolved in bird ancestors. Ashley’s work has set out to ask very broad questions such as, as Ashley put it, “How on earth do these things stay up in the air to begin with?” To more specific questions about the transition of flight in evolution and the transformation in locomotion across a bird’s development.
Ashley explained that this question “opened up a whole other suite of questions in biomechanics and how bones work and how muscles work and what information can we actually get from fossils and what can that tell us about extinct animals’ potential locomotor capacity and their lifestyle.”
Ashley has used tools like XROMM and other novel methods to develop a better understanding of the behavior and biomechanics of flight in developing birds. These birds include the chukar partridge, peacocks, killdeer and ducks. While most young birds can’t fly as effectively as their adult counterparts, she has made interesting findings about how they use their wings for other locomotion adaptations. The locomotory behavior of baby birds today informs us on how the dinosaurs may have moved with similarly less developed ‘proto-wings’.
The rotoscoped forelimbs and hind limbs are from 7–8 day old and 18 day old birds flap-running on 60–65° inclines, in lateral and dorsal view.
From Heers, Ashley M., David B. Baier, Brandon E. Jackson, and Kenneth P. Dial. “Flapping before flight: high resolution, three-dimensional skeletal kinematics of wings and legs during avian development.” PLoS One 11, no. 4 (2016): e0153446.
Every time Ashley finishes her research projects, she, like every scientist, has to go out there and see what the other experts think of her findings. This is something I still find incredibly daunting as an early career researcher – showing your findings and hard work to peers you admire to ensure it is robust scientifically. Ashley agreed, saying, “Everyone struggles with that as we progress as academics. And I think it’s especially hard when you first start out because a lot of times, whether it’s commenting on a paper or a question at a talk or a conversation at a poster session (…), it does seem personal and it is hard not to take that personally and not to be upset about it. And so I don’t think that’s unusual at all. I think we all kind of go through that phase where it does feel very personal, and it never necessarily stops feeling personal.” But receiving critical feedback from your peers is a vital element of science as Ashley said,
“We have to remind ourselves that as scientists, there’s no final answer. (…) When people question it, that’s just a natural part of science. There will always be questions, whether they come from you in the future or your advisor, a friend, or someone you’ve never met. (…) We’re never going to have all the answers. You’re never going to reach that point. Which is part of the reason we all love it, right? There is constantly more to learn and more to explore”
When I asked Ashley how she overcomes creeping thoughts of self-doubt, she offered some great advice.
“I’d say the things that have helped me the most is before I give a presentation or turn something in, I just remind myself of two things. (…) The first thing I tell myself is I love what I do. I love this project. I’ve loved these animals. I’ve grown so much. Regardless of what someone says, they can’t take that away from me. I love this. And then the second thing I remind myself is no matter what questions they ask, I was very thorough with this project. I did a good job. I took care of my animals, I collected good data. I was extremely thorough in my work.”
Currently, Ashley is taking on new challenges in her career. Studying the locomotion behavior of a whole new bird species, the Killdeer, from hatchlings to adults. Ashley devotes months to raising the birds and documenting changes in their wing anatomy, locomotor behavior and morphometrics. All the while, Ashley works as a PI and lecturer at Cal State LA, teaching future generations anatomy and evolutionary biology. But her determination to continue learning remains. “We have so many different species of birds living all over the world,” she says enthusiastically, “so many different body plans, so many different modes of development, and we’re barely scratching the surface in terms of how these animals make it from hatchling to adult. And I’m sure there are loads of strategies that we don’t even know about yet. I think that’s one of the really exciting things about birds, and I love it.”
It is the passion of scientists like Ashley that keeps me motivated as I start my science career. Despite the difficulties, Ashley reminded me of how fortunate we are to do what we do. Her passion for research, her respect for her study animals and her tenacity to keep striving in the field are inspiring. Perhaps all these years of witnessing baby birds achieve the seemingly impossible task of learning to fly would make you believe Ashley has become a naïve optimist. However, I think watching and learning how this amazing feat occurs may lead you to understand like Ashley has, that if we, like birds, trust in our hard work and self-determination, we too can leap into the unknown and fly to where many great discoveries await us.
Check out Ashley’s research website here < https://buildingabird.weebly.com/>
Check out ICB Free read
New Perspectives on the Ontogeny and Evolution of Avian Locomotion
Ashley M. Heers
https://doi.org/10.1093/icb/icw065
and the corrected proof in advanced for 2023
Unexpected Performance in Developing Birds
Ashley M Heers
https://doi.org/10.1093/icb/icad06
Integrative and Comparative Biology 