Researchers have discovered for the first time that chickens fluff their facial feathers and blush when exposed to different stimuli, likely as a way of revealing their inner emotional states. This connection can help improve our management of birds.
If you've ever been struck by the head tilt a dog makes in response to certain verbal expressions of interest or confusion, then you're familiar with the idea that animals can convey emotions through facial expressions. In fact, scientists have established links between facial signals and emotional states not only in dogs, but also in other mammals such as pigs and mice. While birds can also change their facial expressions by flushing their skin and moving their facial feathers, it's unclear whether these signals are related to their emotional state.
In order to clarify this issue, researchers from France's INRAE agricultural research center designed a study to place chickens in various environments and closely observe the changes in their faces through video recording.
They filmed 18 birds of two different species in three different basic scenarios: going about their daily lives on a French farm; being captured and held in a human's arms; and being offered tempting food.
They found that when relaxed and content, female birds have fluffy head feathers. When they are chased, captured and detained, the facial skin color of hens will be dark red, indicating that they are in a state of passive excitement. However, when the birds were given food, their facial skin was less red. The researchers believe this subtle change in skin color from light to dark red can be used to reveal the birds' states of excitement, from positive to negative.
Since INRAE is an organization focused on agriculture and food science, the study concluded that the findings could help improve the treatment of chickens in these environments. But it's hard to imagine a bunch of free-range bird enthusiasts rushing out to see if they can make their chickens blush with joy.
"We conclude that hens' facial expressions reveal their emotions and that blushing is not unique to humans," the researchers wrote in a paper just published in the journal PLOSONE. "This opens up a promising avenue for exploring the emotional lives of birds, a key step in efforts to improve poultry welfare."