Dr. Singer is also the author of Practical Ethics. In the 2nd edition of that book, he says something that I think is both correct and important.

The liberal search for a morally crucial dividing line between the newborn baby and the fetus has failed to yield any event or stage of development that can bear the weight of separating those with a right to life from those who lack such a right.

“Human babies are not born self-aware, or capable of grasping that they exist over time. They are not persons”; therefore, “the life of a newborn is of less value than the life of a pig, a dog, or a chimpanzee.”

Dr. Singer believes that the idea of treating self-aware, non-human animals as non-Persons is speciesism. And to say that human life is always more valuable than the life of a given animal is wrong.