Sage Rohrer

Research Interests:

I’m studying how genetic and environmental factors can drive microorganism colonization in wild birds. My research focuses on how variation in the major histocompatibility complex (MHC) can influence what organisms colonize or infect the host environments of the gut and the blood – e.g. the gut microbiome and blood parasites. I’m investigating these patterns in a severely bottlenecked island system, the Galapagos penguin, as well as a local species with higher genetic diversity, the Eurasian tree sparrow.

This work is supported by grants from the Harris World Ecology Center, the St. Louis Zoo, Sigma Xi, and the NSF GRFP.


2017 – Present: PhD Candidate in Biology at UMSL, co-advised by Dr. Patty Parker and Dr. Lon Chubiz

2019: MSc in Biology, UMSL

2013 – 2017: BS in Biology, Pierre Laclede Honors College certificate, University of Missouri-St. Louis (UMSL)

Research Experience:

  • 2017 – present: Dissertation research in Galapagos marine birds and local passerines.
  • June – July 2018: 6-week field course in Tropical Biology, Organization for Tropical Studies.
  • May 2017 – July 2017: Bird Survey Technician, Audubon Center at Riverlands. Point count observer, surveying nesting bottomland forest birds on Mississippi River islands.
  • August 2014 – May 2015; August – December 2016: Undergraduate Research Assistant, UMSL Parker Lab. Lab testing for avian Plasmodium and Haemoproteus in Galapagos birds.
  • May 2016 – July 2016: Research Intern, Audubon Center at Riverlands. Point count recorder.
  • March 2016: Research Assistant, Missouri Department of Conservation. Rabbit mark-recapture population study at Columbia Bottom Conservation Area.
  • June 2015 – July 2015: Research Assistant, Galapagos Islands with the UMSL Parker Lab. Field work for Galapagos Avian Health Project.


  • Jaramillo, M., Rohrer, S., & Parker, P. G. (2017). From Galapagos doves to passerines: Spillover of Haemoproteus multipigmentatus. International Journal for Parasitology: Parasites and Wildlife, 6(3), 155-161. Link to PDF

Public Profiles:

Research Gate