
That’s not actually true. Animal social structures vary a lot some are male dominant, some female dominant, many are pair bonded or structureless. Even animals people call “matriarchal” (like elephants or bonobos) don’t map cleanly onto human social systems. Using animal behavior to justify how human societies should be organized is also a pretty shaky appeal to nature argument.
That’s cause no system translates over perfectly when you cross structures. But we can agree that matriarchal animal dominant structures that opposes our patriarchal structure, care more for their offspring. Mother bears will fight father bears who threaten cubs and or try kill them and or flee, but in our society a lot of women stick by a terrible father for the sake of kids having a father because of the patriarchal notion fatherless behavior.