Egypt Bonus

To test this idea, Love and her colleagues infected 10 caged canaries (Serinus canaria domestica) with Mycoplasma gallisepticum, or MG, a common bacterial pathogen that causes conjunctivitis and extreme lethargy. Sick birds look “pretty fluffed out,” Love says.

Nine healthy birds were housed in direct view of their sick brethren, but far enough away to avoid infection, which requires direct contact. An identical setup, but with all healthy birds, was located in the same room but on the other side of an opaque divider. Over the course of a month, researchers collected blood samples from the birds, measured various aspects of immune activity and tracked how sick the infected birds looked.