Published Research Articles
18. Simpson RK, Wilson DR, Mistakidis AF, Mennill DJ, Doucet SM. (2021) Sympatry drives colour and song evolution in wood-warblers (Parulidae). Proceedings of the Royal Society, B., 288: 20202804. PDF
Media Coverage: CBC Windsor Morning Radio interview
17. Gayk ZG, Simpson RK, Mennill DJ. (2021) The evolution of wood warbler flight calls: species with similar migrations produce acoustically similar calls. In Press at Evolution.
Media Coverage: University of Windsor Daily News
16. Sepp T, Webb E, Simpson RK, Giraudeau M, McGraw KJ, Hutton P. (2021) Light at night reduced digestive efficiency of developing birds: an experiment with king quail. The Science of Nature, 108: 1-10 PDF
15. Reed S*, Simpson RK, McGraw KJ. (2020) Feather morphological predictors of angle-dependent color changes in parrot plumage. Avian Biology Research, 13: 108-117. PDF
14. McGraw KJ, Chou K*, Bridge A*, McGraw HC*, McGraw PR*, Simpson RK. (2020) Body condition and poxvirus infection predict circulating glucose levels in a colorful songbird that inhabits urban and rural environments. Journal of Experimental Zoology, A, 333: 561-568. PDF
*High school author
13. Demko AD, Sosa-Lopez JR, Simpson RK, Doucet SM, Mennill DJ. (2020) Divergence in plumage, voice, and morphology indicates speciation in Rufous-capped Warblers (Basileuterus rufifrons). Auk, 137: 1-20. Link
12. Simpson RK, Mistakidis AF, Doucet SM. (2020) Natural and sexual selection shape the evolution of colour and conspicuousness in North American wood-warblers (Parulidae). Biological Journal of the Linnean Society, 130: 89-100. link
11. Simpson RK, McGraw KJ (2019) Interspecific covariation in courtship displays, iridescent plumage, solar orientation, and their interactions in hummingbirds. The American Naturalist, 184: 441-454. PDF
Media Coverage: ASU Now
10. Saini C*, Hutton P, Gao S, Simpson RK, Giraudeau M, Sepp T, Webb E, McGraw KJ. (2019) Exposure to artificial light at night increases innate immunity during development in a precocial bird. Journal of Comparative Biochemistry and Physiology A, 233: 84-88. PDF
9. Simpson RK, McGraw KJ. (2019) Experimental signal mis-matches uncover specificity of evolutionary links between multiple signals and their interactions in hummingbirds. Evolution, 73: 436-451. PDF
Media Coverage: Evolution Digest
8. Simpson RK, McGraw KJ. (2018) It’s not just what you have, but how you use it: solar-positional and behavioural effects on hummingbird colour appearance during courtship. Ecology Letters, 21: 1413-1422. PDF
Media Coverage: Science (Video), Forbes
7. Simpson RK, McGraw KJ. (2018) Multiple signaling in a variable environment: expression of song and color traits as a function of ambient sound and light. Biotropica, 50: 531-540. PDF
6. Simpson RK, McGraw KJ. (2018) Two ways to display: male broad-tailed hummingbirds exhibit different dynamic color tactics based on sun orientation. Behavioral Ecology, 29: 637-648. Link
Media Coverage: Oxford University Press Tumblr
5. Simpson RK. (2017) Courtship and territorial behaviors of three hummingbird species in Arizona. Arizona Birds, 2017: 1-7. PDF
4. Ligon RA, Simpson RK, Mason NA, Hill GE, McGraw KJ. (2016) Evolutionary innovation and the diversification of carotenoid-based pigmentation in finches. Evolution, 70: 2839-2852. PDF
3. Hutton P,* Ligon RA, McGraw KJ, Seymoure BM, Simpson RK. (2015) Dynamic color communication. Current Opinions in Behavior, 6: 41-49. PDF
*All authors contributed equally
2. Simpson RK, Johnson MA, Murphy TG. (2015) Migration and the evolution of sexual dichromatism: evolutionary loss of female coloration with migration among wood-warblers. Proceedings of the Royal Society B., 282: 2015375. PDF
Media Coverage: Science, Nature, IFL Science, Phys.org, Nature World News, Richard Dawkins Foundation
1. Murphy TG, West JA, Pham TT, Cevallos LM, Simpson RK, Tarvin KA. (2014) Same trait, different signals: Unlike females, male goldfinches do not signal status with bill color. Animal Behaviour, 93: 121-127. PDF
Simpson RK. 2018. How do male hummingbird dance moves alter their appearance? Oxford University Press blog guest post (link).
Simpson RK. 2014. Ask A Biologist Top Question: Why do leaves change color. ASU’s Ask A Biologist (link).
Simpson RK. 2014. Biology Bits: Feathers. ASU’s Ask A Biologist (link).
Created in: 2017. How Animals Can Change Colors. Science Insider (link).
Credited in: Coneflower Studios. 2016. Super Hummingbirds. PBS Nature (link).
Featured in: Sturm, M. 2014. Faint of Heart Need Not Apply. ASU’s SOLS Magazine. 10, 1: 19-23.