Research - Health, stress, and parasites

Birds as sentinels of ecological health

Birds forage at multiple trophic levels and integrate integrate the effects of environmental contaminants more quickly than humans because they have high rates of respiration and rapid rates of growth.  Because of these features, avian health can provide valuable and rapid insights into the health of the ecosystem as a whole, of which humans are a part.  Avian health parameters can be used to quantify the success of restoration projects, to understand the mechanisms underlying changes in abundance, and as a proxy for human health in rural and underserved areas.  We are conducting several projects investigating avian health in relation to environmental stressors and disturbance.

Interactions between stress, hormones, and immune function in birds

Climate change and the exponential growth of the human population continue to expose vertebrates to an increasing rate and novelty of stressors.  One of the great challenges for ecologists is to understand how rapidly and efficiently vertebrates will be able to adjust to these changes, and whether that adjustment will come at a cost to fitness. Glucocorticoids are critical for the vertebrate stress response, but they also have important interactions with the immune system, which can have real effects on infection rates of vertebrates. This research seeks to understand the interactions between the hormonal stress response and immune function in wild captive and free-living birds.

Consortium for Avian EcoHealth

Wildlife and ecosystem health are closely allied to human health and healthy communities. The susceptibility of the Gulf Coast region to natural disasters (e.g., hurricanes), human-facilitated disasters (e.g., the Deepwater Horizon spill) and climate change (e.g., rising sea levels) make it imperative that we develop ways to rapidly assess the health of this ecosystem, and indeed other ecosystems in Texas (e.g., the Edwards Aquifer) that have similar competing demands for resources. By extension, it is also imperative that we develop baseline data for what is considered a normal range of ecosystem health parameters.  To accomplish this, data is needed from diverse ecosystems and organisms that are abundant and readily sampled, and from which a diverse data set can be assembled.  This integrative research program uses birds as bio-indicators of ecohealth across Texas, including research in the following areas: avian blood analytes, blood parasites, ecto-parasites, nutritional status, genetic diversity, ecotoxicology, endocrinology, and histopathology. 

Bird health in relation to disease and contaminants in the Gulf of Mexico

The Gulf of Mexico coast possesses a wealth of natural resources that stimulate economic growth through manufacturing, commerce, and tourism. Galveston Bay, TX, alone, is responsible for approximately 50% of chemical and 30% of petroleum production in the United States, while supporting 65% of Texas’s oyster harvest, and 40% of its seafood harvest. This economic importance has led to a 150% increase in population growth along the Gulf of Mexico between 1960 and 2008. These bustling coastal areas also provide critical habitat for wildlife and over 300 bird species rely on Gulf habitat.  As human populations and industrial activities have increased along the Gulf coast, so too has contamination of coastal waterways and wetlands, posing threats to wildlife and human health.  This research seeks to (1) evaluate potential threats to the health of coastal waterbirds in the Gulf, (2) determine the effects of disease and contaminants on bird physiology, behavior, and population productivity, and (3) investigate interactive effects between multiple contaminants on bird health.