Humans have profound impacts on the environment. For example, climate change is expected to increase the frequency of extreme and unpredictable weather in many parts of the world. Similarly, urbanization and urban sprawl are altering the environment in unprecedented ways. A critical goal for biologists is to predict how organisms will cope with such changes in their environments. Our lab's approach is to determine how organisms found along gradients of environmental conditions are behaviorally or physiologically adapted to survive and reproduce in different habitats, as well as whether these coping strategies are plastic or evolved.
The evolution of behavioral & endocrine flexibility
We are starting exciting work on European starlings (Sturnus vulgaris) at Kennesaw State University. We have set up colonies of free-living starlings in Georgia along an urban to rural gradient—these starlings are an ideal study system as they readily breed in nest boxes, and are easy to monitor and manipulate. Using an intra-specific comparative approach, our team will address central questions in evolutionary ecology, including:
Ongoing projects & collaborations
The Guindre-Parker lab is fortunate to continue working with collaborators on long-term datasets, including the Kluane Red Squirrel Project in Canada's Yukon and African starlings in Kenya. While our team no longer participates in field data collection in these study systems, students may have the opportunity to work with existing samples or datasets in a few cases. Please get in touch with me to learn more about these options.
The evolution of maternal effects in North American red squirrels
While glucocorticoid hormones play an important role in allowing animals to respond to changes in their environment, it remains unclear whether endocrine flexibility represents phenotypic plasticity or has evolved in response to fluctuating environmental conditions. We are continuing to collaborate with the Kluane Red Squirrel Project (work that began under an NSERC postdoctoral fellowship) to examine whether a glucocorticoid-mediated maternal effect represents an evolved response to living under highly fluctuating population density. This work addresses an important knowledge gap in evolutionary physiology, and will provide the first evidence as to whether maternal effects have evolved in response to environmental fluctuations.
Physiological mechanisms linking environment and fitness
Animals primarily interpret and adjust to their environments via physiological responses. Environmental changes stimulate changes in animal physiology, which subsequently alter metabolism or behaviour to allow an animal to respond appropriately to its environment. We are continuing to explore how fluctuations in environmental conditions such as rainfall or temperature shape a suite of physiological traits which may affect breeding decisions, investment in parental care, and ultimately fitness in African starlings.
Mechanisms underlying life-history trade-offs
All sexually reproducing organisms are faced with a fundamental decision: to invest valuable resources and energy in reproduction or survival. We continue to examine the environmental and social drivers of this trade-off, called the ‘cost of reproduction’. We take an integrative approach, by assessing multiple physiological traits thought to mediate a cost of reproduction, as well as the consequences of pair-breeding or cooperative breeding on the physiological costs of reproduction.
Coping with environmental unpredictability
Our team continues to explore how populations of the same species have acclimated or adapted to naturally unpredictable environments in order to understand how vertebrates facing unpredictable conditions for the first time may cope with global warming. To do so, we are analyzing datasets and biological samples from a large-scale sampling effort in Kenya to determine whether populations of African starlings living in habitats that vary in mean annual rainfall as well as in the predictability of this rainfall respond similarly to stressors.
Previous work focused on achromatic plumage signalling in the Arctic-breeding snow bunting (Plectrophenax nivalis). Even simple black and white plumage may serve in complex, multi-ornament signalling. Among other signals, snow buntings display their condition through the size of their alula, a small set of black feathers that contrast against their white breast. Achromatic plumage may act as a condition-dependent signal across many species of birds.