Research — Jordan Boersma

how does environmental variation influence physiology, behavior, and sexual signals?

I use long-term physiology and behavior sampling combine to illustrate the mechanisms by which organisms respond to variation in the abiotic and social environment. These studies have helped resolve how organisms adapt to harsh weather conditions found at high elevations, and major environmental disturbances like drought and wildfire. By testing how variable abiotic conditions and social contexts affect physiological mediators like hormones, I establish the mechanistic basis of response to changing conditions.

Relevant Publications

Mitchell et al. 2018. Experimental Amelioration of Harsh Weather Speeds Growth and Development in a Tropical Montane Songbird. The American Naturalist
Boersma et al. 2021. Wildfire affects expression of male sexual plumage through suppressed testosterone circulation in a tropical songbird. Journal of Avian Biology
Boersma et al. 2022. Male White-shouldered Fairywrens (Malurus alboscapulatus) elevate androgens greater when courting females than during territorial challenges. Hormones and Behavior
Boersma et al. 2022. Drought disrupts year-round breeding readiness in a tropical songbird. Avian Conservation and Ecology

Media Coverage

New Scientist, Inside Science, WSU Insider

Male Red-backed Fairywrens were less ornamented during the fire year, likely due to lower mean circulating testosterone **(a)**, given that ornamented males had higher circulating testosterone in this study **(b)**, which is consistent with previous studies in this system. Figures modified from Boersma et al. 2021 , Journal of Avian Biology.

Graphical abstract for Boersma et al. 2022, *Hormones and Behavior*

Precipitation declined substantially during the 2015-16 El Niño induced drought in New Guinea **(a)**, which was associated with several male White-shouldered Fairywrens losing their cloacal protuberance **(b)**, a phenomenon not previously observed in this year-round breeding species. From Boersma et al. 2022, *Avian Conservation and Ecology.*

causes and consequences of female ornamentation

Colorful signaling traits (“ornaments”) are vastly understudied in females. I study the White-shouldered Fairywren (Malurus alboscapulatus), a species endemic to New Guinea that exhibits pronounced variation in female ornamentation across its range. These studies employ a combination of genetic, transcriptomic, hormonal, and behavioral tools to determine the proximate causes of ornaments and the ultimate consequences of their expression.

**(a)** An unmanipulated unornamented female White-shouldered Fairywren. **(b)** Map of Papua New Guinea depicting the location of our two field sites. **(c)** An unmanipulated ornamented female from the *M. a. moretoni* subspecies. Testosterone-implanted females displaying a gradient of ornamentation: **(d)** no ornamentation, **(e)** prominent shoulder patches only, **(f)** prominent shoulder patches and darker brown plumage. Figure from Boersma et al. 2020, *Behavioral Ecology.*

Relevant Publications

Enbody et al. 2018. Female ornamentation is associated with elevated aggression and testosterone in a tropical songbird. Behavioral Ecology
Boersma et al. 2020. Testosterone induces plumage ornamentation followed by enhanced territoriality in a female songbird. Behavioral Ecology
Enbody et al. 2022. The evolutionary history and mechanistic basis of female ornamentation in a tropical songbird. Evolution

Ecology and conservation of enigmatic ecosystems and understudies species

First video of the Black-naped Pheasant-pigeon, a species lost to science since the 1800s.

Hunter interview method used to find the Black-naped Pheasant-pigeon.

Relevant Publications

Gregg et al. 2020. Survey of the montane avifauna of Fergusson Island, Milne Bay Province, Papua New Guinea. Bulletin of the British Ornithologists’ Club
Brooks et al. 2023. Human and wildlife use of mountain glacier habitat in western North America. Journal of Field Ornithology (In Press)
Hotaling et al. 2023. Community science for enigmatic ecosystems: Using eBird to assess avian biodiversity on glaciers and snowfields. Northwest Science (In Press)

Media Coverage

BBC News, The Independent, People Magazine, Audubon Magazine, Cornell Chronicle, USA Today, CNN, The Times, Science Alert, International Business Times, Upworthy, NDTV, Yahoo! News, The Express, Good News Network, The Weather Channel, Daily Express, Mongabay

My lifelong pursuit of exploring remote forests and mountainous ecosystems intersects with my desire to study and conserve the often understudied and unique animals that inhabit these incredible places. In the US, I have contributed to studies that show that glaciers harbor an underappreciated level of biodiversity. In Papua New Guinea, I have led expeditions to remote mountains and river valleys on Fergusson Island, where we work with local people to uncover new records for this Birdlife International-designated Endemic Bird Area. In 2022 we worked with hunters on Fergusson to provide the first record of the Black-naped Pheasant-pigeon (Otidiphaps insularis), a critically endangered bird endemic to the island that has not been documented since the 1800s. We are now working with our local partners to study and conserve this culturally-important and imperiled species.