Research
Extreme weather impacts birds
Climate change isn’t just raising temperatures worldwide, it’s greatly increasing the frequency and intensity of extreme weather events, such as heat waves, cold snaps, drought and storms. In my recent position in the Zuckerberg lab at UW-Madison and in collaboration with the Cornell lab of Ornithology, I used eBird, a citizen science database, and NASA satellite weather data to examine how diverse North American bird species are responding to extreme heat and drought in the summer and polar vortexes in the winter. By examining how responses vary across species, we can anticipate which species are most likely to be at risk with climate change.
Climate change influences outbreaks of deadly wildlife diseases
Amphibians are the most threatened vertebrate taxa on Earth, partially because they are highly susceptible to the emerging infectious disease chytridiomycosis, caused by a deadly fungal pathogen that has spread worldwide over the last 60 years. It has widely been suspected that temperature plays an important role in driving outbreaks of this disease, but the precise conditions that best promoted outbreaks remained uncertain. My PhD work in the Rohr lab at the University of South Florida involved examining how the ecology of the host influences the impact of temperature in driving chytridiomycosis outbreaks. Using lab and field data, we found that cold-adapted hosts experienced greatest disease risk under unusually warm conditions, while warm-adapted hosts were at greatest risk when it was unusually cool. We have since extended this framework to predict disease outbreaks across a wider variety of wildlife species and project global shifts in wildlife disease risk under climate change. This research resulted in an outstanding dissertation award for the 2016-7 academic year at the University of South Florida.
The timing of annual events is shifting
One of the most well-known responses of wildlife species to climate change involves shifting of phenology, or the timing of annual events including migration, breeding, and emerging from hibernation. In the last 50 years, numerous wildlife species have been documented advancing the timing of these activites earlier in the spring. During my PhD work in the Rohr lab, I conducted a meta-analysis across over 100 published studies and found that invertebrates and amphibians are shifting much faster than birds and mammals, suggesting that predators may be arriving or emerging too late, missing peaks in prey availability. Further, we showed that phenological shifts in temperate areas are primarily driven by temperature, while precipitation plays a greater role in driving shifts in subtropical areas.
Temperature drives human vector-borne disease transmission
Infectious diseases of humans are emerging at an alarming rate with increasing globalization and warming temperatures. West Nile virus, Zika virus, and COVID-19 have all reached North America in only the last 25 years. I’ve collaborated with researchers at Stanford University on a number of projects modeling temperatures at which transmission of several human vector-borne illnesses is most likely. This work is done via a combination of 1) mechanistic transmission models using published temperature experiments with mosquito vectors, and 2) real-world human case data from the CDC, used to validate models. We’ve discovered that peak transmission of several vector-borne diseases, including Zika, dengue and West Nile viruses, occurs at more moderate temperatures than previously thought.