18. Simpson RK, Wilson DR, Mistakidis AF, Mennill DJ, Doucet SM. (2021) Sympatry drives sexual signal divergence in wood-warblers (Parulidae) In press at Proceedings of the Royal Society, B.
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.
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.