This is my third blog about feathered friends, partly because we have lots of them in our collections, but also because I find them fascinating! In my last blog, I wrote about some of the larger birds people recognize because of their loud honks (see Let’s Hear It for Honking Swans) and their interesting tracheal (windpipe) anatomy. Some Gouldian finches have an uninvited guest in their windpipe: tracheal mites. These microscopic, yet sometimes large enough to see with the naked eye, mites are the species Sternostoma tracheacolum. They inhabit the airways of small, exotic finches and canaries. There they latch onto the lining of the trachea and lungs, making it harder for air to pass through the bird. The mites also cause inflammation and other damaging changes that may result in pneumonia and respiratory illness, with occasional fatal results.When a Gouldian finch is brought into necropsy, one of the first places we look is in the trachea. Often the culprit for the bird’s decline in condition is one to dozens of black specks. Under the magnification provided by a dissecting scope, I am able to look closely at these 8-legged mites. By examining the number of mites and severity of the infection at necropsy, we are helping the clinical veterinarians determine why these birds are so susceptible and the most effective treatment. The more we can learn about diseases like this one, the better able we are to devise prevention and treatment strategies.
This is one of the many ways in which Wildlife Disease Lab helps keep our animal collection healthy. Hopefully, in the future the Gouldian finches will be cured of their scratchy throats!
Rachael Holland is a research technician in the Wildlife Disease Lab, San Diego Zoo Institute for Conservation Research.