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Undergraduate Researchers

Krystyna Horn, Biological Sciences

Sexual Signaling With Colored Pigments: Are Eastern Meadowlarks Hiding Costly Carotenoids?

Faculty Mentor: Dr. Kevin Omland

My goal is to examine the evolution of coloration with a specific interest in sexual signals. Eastern Meadowlarks express yellow pigments in the feathers of the breast, but a small area - in the shape of a V - is black. Two possible hypotheses explain this: (1) Carotenoid expression has been lost from an ancestral state or (2) Carotenoid expression has been retained "under" black pigments. If carotenoid expression has been lost, then this would suggest that depositing carotenoids in feathers is costly. Birds and animals are unable to synthesize carotenoids de novo, so they must be obtained from a dietary source. As previous studies have indicated that the expression of carotenoids is a costly sexual signal (McGraw 2006), then it would also be costly to deposit carotenoids that are masked in certain areas of the body. In a related species, the Bullock's Oriole, black feathers from the nape were found to have underlying orange coloration when bleached (Butcher & Rohwer 1989). This suggests that the Eastern Meadowlark may be masking carotenoids with its black breast feathers. This research will determine the presence or absence of carotenoids in the black breast feathers to better understand the evolution of sexual signals and the costliness of expressing them. This might help explain the variety of colors and patterns we see in birds.

When and how did you find out about the URA program?

I attended URCAD last year on the suggestion of one of my professors. I heard about the URA program this year from my lab mentor who suggested I submit a proposal.


Was the application difficult to complete? How much did your mentor help you with the application?

The application is very straightforward and not difficult to complete. Aside from providing guidance with my research prior to applying, my mentor assisted me with the application by guiding me in writing an abstract and proofreading the application before submission. Overall, I did not require a great deal of help to complete the application.


What have you gained from being a URA scholar? What is your most recent (or most interesting) research activity? 

How did you find your mentor for this project?

I have definitely learned how important it is to be organized and methodical regarding research. I worked in my mentor's lab for a semester assisting a graduate student before he suggested that I apply to be a URA scholar. Most recently I have been completing the last stages of my research, organizing my results, and putting together all of the information for review by my mentor.


How did you know this was the project you wanted to do?
I had worked with a graduate student in a similar area (carotenoid coloration) and found that I was quite interested in the subject. My mentor suggested a direction for my research that would complement or confirm the data that the graduate student I had worked with had found and once I started working on it I knew it would be interesting to look at the overall results.
How much time do you put into it?
The majority of my research took place over the Summer and the beginning of the Fall semester.
What academic background did you have before you started?
I have been studying biology at UMBC since 2008, but I had little experience in Ornithology (aside from what I learned in Ecology & Evolution) until I started working in Dr. Omland's lab in 2009. 


What has been the hardest part about your research? The most unexpected thing?

The hardest part about my research has been maintaining a high level of organization in my data. 


How does your research relate to your work in other classes?

My research related quite well to the work I did in BIO 483 (Genes to Genomes) regarding the skills I needed to research and answer questions. 


What is your advice to other students about getting involved in research?

Definitely go for it! There is nothing more rewarding than taking control of research in an area of your interest. 


What are your career goals?

I hope to take a different route and research Linguistics at graduate school.