Linking toxins and eggshells

Guelph, ON – Measuring egg colour may offer a quick, inexpensive and non-destructive way to monitor areas of concern and evaluate potential human health risks according to new research.

Environmental contaminants can cause birds’ eggs to change colour, offering a possible tool to estimate and monitor environmental toxins, according to this study by a University of Guelph researcher. Daniel Hanley, a Mitacs Elevate post-doctoral fellow in the Department of Integrative Biology, found that not only can pollutants influence the colour of herring gull eggs, but the colour of these eggshells can predict contaminant load with 84-per-cent accuracy.

Pigments that give eggshells their colour are believed to be the same for all birds, says Hanley. Along with University of Windsor researcher Stéphanie Doucet, he used a spectrometer to measure the colour of Great Lakes herring gull eggs and evaluate the influence of numerous toxins, such as insecticides and industrial by-products.

The eggs were collected over 40 years by the Canadian Wildlife Service’s Great Lakes herring gull monitoring program – one of the longest-running programs of its kind in the world.

The paper appears in the Journal of Applied Ecology.