16. Simpson, RK, McGraw, KJ, Doucet, SM. Hummingbird feather photonic structures co-evolve with courtship displays and signal interactions. In Review at Nature Communications
15. Earl, AD, Kimmitt, AA, Simpson, RK, Yorzinski, JL. Female ornamentation in a lekking bird: bright females dominate. In Review at Animal Behaviour.
14. Simpson, RK, Mistakidis, AF, Doucet, SM. The environment, sexual selection, and natural selection have different effects on plumage color and conspicuousness in wood-warblers. In Review at The American Naturalist.
13. Sepp, T, Webb, E, Simpson, RK, Giraudeau, M, McGraw, KJ, Hutton, P. Light at night reduces digestion efficiency of developing birds: an experiment with king quail. In Review at Biology Letters.
12. Reed, S*, Simpson, RK, McGraw, KJ. Feather morphological predictors of angle-dependent color changes in parrot plumage. In Review at Journal of the Royal Society Interface.
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.
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. J. 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, G.E., 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, R.K. 2018. How do male hummingbird dance moves alter their appearance? Oxford University Press blog guest post (link).
Simpson, R.K. 2014. Ask A Biologist Top Question: Why do leaves change color. ASU’s Ask A Biologist (link).
Simpson, R.K. 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.