Wildfire Smoke and Respiratory Physiology

Wildfires are becoming increasingly common during the spring, summer, and fall seasons. Particulate matter generated from the combustion of wood and other materials is harmful to human respiratory health, but how birds are influenced by particulate matter from wildfire smoke is unknown. My lab will be investigating how particulate matter impacts respiratory physiology in migratory and resident songbirds and shorebirds, asking questions at the individual level up to population level! This work is currently starting up, so stay tuned for our findings!

High-Altitude Flight in Migratory Birds

Recently, tracking studies have identified song- and shore-birds flying above 5,000m during migratory flight! What adaptations or plastic responses allow these birds (found at low altitude during breeding and wintering seasons) to fly at such altitudes is unknown. My post-doc work investigated whether these birds exhibit seasonal plasticity and/or genetic adaptations that allow for them to maintain oxygen uptake during the migratory season. We showed that migratory songbirds exhibit enhanced oxygen uptake and transport to the flight muscle during the migratory season that aid in their migratory flights! Whether these responses are important for flight at high altitude was investigated using the AFAR wind tunnel at the University of Western Ontario! 

Much of this work is currently being written up, but check out these papers:

Control of Breathing in Challenging Environments

Life at high altitude is characterized by cold temperatures and hypoxia. For animals to survive and thrive in these conditions, they have to overcome the challenge of maintaining oxygen supply to tissues in a low oxygen environment through modifications in oxygen uptake and transport. This research has focused on how modifications in the control of breathing (eg. tidal volume and breathing frequency) are altered in high-altitude taxa compared to low-altitude conspecifics and whether changes in oxygen sensing in the carotid bodies (peripheral chemoreceptors) influenced these findings!

Most of this research focused on high-altitude deer mice...
...with other projects focusing on high-altitude Peruvian ducks!

Gene Variants and their Influence on Physiology

Directional selection on gene variants beneficial for life at high altitude have recently started being identified in many high-altitude taxa. Our understanding of how these variants influence the physiology of animals at high altitude is unknown, but recent research we've conducted on deer mice has shown that high-altitude variants of haemoglobin and EPAS1 (HIF-2alpha) can influence ventilatory response to hypoxia and acclimation responses associated with chronic hypoxia (e.g. ventilatory acclimatization to hypoxia, carotid body hypertrophy).

Here are some papers related to this research:

Developmental Plasticity in Challenging Environments

Much of our understanding of the adaptations animals have evolved at high altitude is based on studies focused on adults. Lab experiments have shown that hypoxia exposure during early stages of development can influence the adult phenotype, suggesting that animals living at high altitude may have evolved unique mechanisms to cope with this challenging environment during early life. In conjunction with Dr. Cayleih Robertson, we've investigated developmental plasticity in the control of breathing of high-altitude deer mice and found that many aspects of oxygen sensing are delayed in development and rely on the enhanced haemoglobin binding affinity, characteristic of high-altitude deer mice.