Observing a bird with its eyes open after death is a common sight that prompts questions. Unlike humans, birds can appear to die with their eyes fixed in an open position. This observation leads to curiosity about the biological reasons and how to determine if a bird is deceased.
The Biological Reality
Birds possess a unique eye structure that explains why their eyes may remain open after death. They have three eyelids: an upper, a lower, and a transparent or translucent third eyelid called the nictitating membrane. The lower eyelid moves upwards to meet the upper one, but the nictitating membrane, which sweeps horizontally across the eye, is primarily responsible for cleaning, moistening, and protecting the eye while allowing the bird to maintain vision. Birds are capable of closing their eyes, and often do so during sleep.
Upon death, the muscles in a bird’s body relax. The active control over the eyelids, including the nictitating membrane, ceases. Since the upper and lower eyelids may not actively close, and the nictitating membrane no longer sweeps across the eye, the eyes can remain in an open state. After this initial relaxation, rigor mortis, a stiffening of the muscles, typically begins to set in a few hours post-mortem. This process can then maintain the eyes in their open appearance.
Distinguishing Life from Death
Determining whether a bird is truly deceased requires careful observation, as open eyes alone are not a definitive indicator. A lack of any movement, including the absence of breathing (no rise and fall of the chest), and no detectable heartbeat are strong signs of death. If the bird’s body feels cold to the touch and its legs and feet are stiff, it is likely deceased.
Sometimes, a bird may appear lifeless if it is stunned or in shock, but it might still show subtle signs of life, such as faint blinking, slight twitching, or shallow breathing. It is advisable to observe the bird from a distance for a period, perhaps for up to two hours, to see if it recovers. If no signs of life are observed after this time, the bird is likely dead. When encountering a deceased wild bird, it is generally recommended to avoid direct contact due to potential disease transmission, and instead report the finding to relevant authorities if necessary.