The yawn enables an old bull hippo to show everyone else in the hippo pool who is boss. It also serves as a toothy warning to any intruders who would dare trespass into his river domain.
ऐसी उबासी सबको यह जताने में कि तालाब में किसका हुक्म चलता है, एक वयस्क नर हिप्पो की मदद करती है ।