It is amazing how time can fly in grad school. It did not seem that long since I last blogged, but here we are a month later. I mostly blame writing an NSF DDIG (a really big graduate student grant), but I also do not always have the best memory….. Anyways, I actually have not gone on many adventures in the past few weeks, but through writing my NSF DDIG, I have reflected a lot on my path from starting graduate school to where I am now, and so this post is going to be on how I initially became interested in hummingbirds (a weird accident) and how I ended up with my current dissertation work.
For starters, when I arrived at ASU, hummingbirds and iridescent coloration were no where on my radar for potential dissertation topics. I have always been interested in the diversity in animal coloration and questions about why animals use multiple traits to communicate (e.g. song and colorful plumage are both used for communication in many bird species), so my project now definitely still falls in that broad interest. But, I was going to Dr. Kevin McGraw’s lab, a world expert on bird pigment coloration, specifically carotenoid coloration (responsible for many of the reds, yellows, and oranges, such as in house finches or yellow warblers), so I was looking into species that either hard multiple different carotenoid colors, such as the western tanager:
Or species like the northern cardinal, which use different types of pigments to color themselves (the red is carotenoids while the black face mask is due to melanins).
I had originally given thought to non-pigmented colors to some degree, such as the blue coloration in the painted bunting or varied bunting, which is due to specific arrangements of the nanostructure of their feathers. Overall, it seemed that I was focused on why certain birds/animals have multiple colors. But then everything changed when ASU teamed up with the Smithsonian Tropical Research Institute in Panama and offered semester-long fellowships to potentially start up dissertations in the tropics. This was an amazing opportunity, which I immediately jumped on.
At first, I wanted to keep the multiple color patches idea and study some of the extremely colorful tropical birds, but I was told that many of the birds I was thinking of studying, such as the golden-hooded tanager (below), were not very common and/or lived in the canopy, which would make things very difficult. So I ended up shifting my question from multiple color patches to multiple signals and studied song and color in an understory bird – the red-throated ant-tanager.
My work in Panama went fairly well for a first field season, but difficulties during that fieldwork were not why I switched to hummingbirds. My switch to hummingbirds came from a combination of watching the many species of hummingbirds feeding and fighting at our hummingbird feeders in Panama and reading a specific paper – Iridescence: a functional perspective – which has come to be one of the most influential papers I have read to date.
And so, I began many thought experiments and discussions with fellow researches to come up with a project involving iridescent coloration using hummingbirds as my model. For a while I was thinking about looking at how hummingbirds might use their coloration to communicate with other species as they fought at feeders, but my idea switched to wanting to study the use of coloration within species and how that might have evolved. And so I returned to the United States with this idea in mind and began working it into a dissertation project with Kevin. Like a good advisor, he challenged me to continue to craft my idea and find gaps in the field to make a novel and exciting dissertation. And around the same time, he introduced me to Dr. Christopher Clark, a new professor at UC Riverside, who studies hummingbird courtship and acoustics. Eventually we visited him at one of his field sites and saw the hummingbirds in action.
It was then, when I learned what I could and could not do with these birds and was able to finally craft my dissertation project. I was going to (and am now) studying how hummingbird plumage coloration and courtship displays co-evolved and interact to produce the colors females see as males display!
Another huge influence on my idea developments came from my interactions and amazing discussions with my two former lab mates Dr. Russell (Rusty) Ligon and Dr. Brett Seymoure, who were both studying color communication and sensory ecology. It was a great time for developing my ideas as Rusty was in his 4th year when I started and Brett in his 3rd, so I had a good deal of overlap with them.
Now, both Rusty and Brett have graduated, and the lab has changed quite a bit. Most of Kevin’s students are very mechanistically focused (meaning they are interested in studying the physiological or biochemical underpinnings behind behavior and coloration), such as my lab mate Pierce Hutton, who is studying anthropogenic effects on house finch coloration and behavior. This has been great, because it is forcing me to think more like that (I typically think about the functions and evolutionary history of behavior and coloration). I am currently working to integrate mechanistic studies into my current hummingbird work, and this is something I am building with my DDIG proposal (more on that if I get it!).
So that is now I transitioned from starting grad school to studying the evolution of hummingbird coloration and courtship displays. I hope you enjoyed my story!