Pelican upper lip bulge is one of the common manifestations of birds, and they usually show this behavior when they are in danger or alert. This expression is similar to human facial expression, which can make other animals feel their emotions and state. In protected areas and zoos, seeing pelicans with pursed lips may be the tension caused by adapting to a new environment or facing new visitors.

Pelicans not only bulge their lips when facing danger and vigilance, but also show the behavior of bulging their lips when courting and breeding. This behavior helps to attract the attention of the opposite sex and show their health and fertility. Therefore, during this time period, pelicans with upturned lips are usually very active and energetic.

Generally speaking, the bulge of the pelican's upper lip is a common expression, which can show the mood and state of these birds and attract the attention of the opposite sex. We need to know their ecological habits and behavioral characteristics as much as possible while protecting them, so as to get along with them more harmoniously.