News Release
Contact: Sondra Katzen, Public Relations, 708.688.8351,
May 23, 2018
Chicago Zoological Society Publishes New Review Article on a Non-Invasive Physiological Biomarker in Animal Welfare Research
According to the new trailer for Solo: A Star Wars Story due out May 25, Han Solo has been running scams on the streets since he was 10 years old. Having participated in all of those mischievous cons could have been stressful or, since he has mostly been successful, could this have resulted in a positive emotional state? Immunoglobulin A (IgA) could unlock the answer to that very question. The new review article published in the journal Hormones and Behavior by the Chicago Zoological Society, which manages Brookfield Zoo, highlights IgA as a non-invasive physiological biomarker in animal welfare studies. Used for many years as a marker in humans to look at physical and psychological well-being, the review article details how measuring IgA can also enhance or benefit animal welfare studies.

“Animals in accredited zoos and aquariums receive high levels of care, but we are always looking for new ways to ensure the animals have the opportunity to thrive,” said Lance Miller, Ph.D., vice president of conservation science and animal welfare research. “Using new scientific tools to assess the welfare of animals can help us ensure they are experiencing a positive emotional state.”  When animals are experiencing good welfare, their long-term IgA concentrations should stabilize at higher levels. Examining IgA levels in context with other indicators of animal welfare such as behavior, can give researchers a more complete picture of the current welfare state of an animal."

While historically the field of animal welfare has focused on reducing the negative, zoos and aquariums want to ensure animals are not only experiencing good welfare, but that they are thriving. “To meet this goal, non-invasive tools that allow us to determine whether animals are experiencing positive emotional and welfare states are essential,” said Molly Staley, Ph.D., postdoctoral fellow for the Chicago Zoological Society. “IgA not only provides us with information about an animal's health and welfare, but is also best measured using non-invasive samples such as feces, which means we can collect samples without making any changes to animal care practices.”

There is a good amount of research looking at IgA in humans, however, there have been fewer efforts within zoos and aquariums. The difficult aspect is that IgA is an immune protein and can vary greatly across species. Additional work will be needed to develop IgA assays for different species found in zoos and aquariums as highlighted in the review, and with the right efforts, researchers might even be able to develop an IgA assay for wookiees.

The article, “Linking stress and immunity: Immunoglobulin A as a non-invasive physiological biomarker in animal welfare studies” can be freely downloaded at,QxXSaRg until June 29, 2018. Authors of the review article include Molly Staley, Ph.D., postdoctoral fellow for the Chicago Zoological Society; Melinda Conners, Ph.D., research associate/advanced post-doc for Old Dominion University; Katie Hall, Ph.D., postdoctoral fellow for the Chicago Zoological Society; and Lance Miller, Ph.D., vice president of conservation science and animal welfare research for the Chicago Zoological Society.
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About the Chicago Zoological Society
The mission of the Chicago Zoological Society is to inspire conservation leadership by connecting people with wildlife and nature. The Chicago Zoological Society is a private nonprofit organization that operates Brookfield Zoo on land owned by the Forest Preserves of Cook County. The Society is known throughout the world for its international role in animal population management and wildlife conservation. Its Center for the Science of Animal Care and Welfare is at the forefront of animal care that strives to discover and implement innovative approaches to zoo animal management. Brookfield Zoo is the first zoo in the world to be awarded the Humane Certified™ certification mark for the care and welfare of its animals, meeting American Humane Association’s rigorous certification standards. Open every day of the year, the zoo is located at 8400 31st Street in Brookfield, Illinois, between the Stevenson (I-55) and Eisenhower (I-290) expressways and is also accessible via the Tri-State Tollway (I-294), Metra commuter line, CTA and PACE bus service. For further information, visit


Sondra Katzen
Media Relations Manager
Office: 708-688-8351
Cell Phone: 708-903-2071


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