Should Animals Have Human Rights?

I've recently reread Sharyn McCrumb's mystery novel IF I'D KILLED HIM WHEN I MET HIM, which includes a subplot about a woman who wants to marry a dolphin. That character argues that dolphins are intelligent, sensitive beings who should be treated as persons under the law. She also maintains that such a relationship wouldn't be animal abuse because male dolphins are quite -- assertive -- and have not infrequently attempted to mate with their keepers.

The upper intelligence range of some animals, such as dolphins, chimpanzees, octopuses, crows, and parrots, is said to overlap the lowest intelligence range of some human beings. Given this overlap, should highly intelligent nonhuman animals be granted rights equivalent to ours even though they don't belong to our species?

The Treehugger site discusses the concepts of rights and duties; it also distinguishes "animal rights" from the position of animal welfare. It states that animal rights advocates don't "want nonhuman animals to have the same rights as people":

What Are Animal Rights?

It defines the philosophy of animal rights as "the belief that humans do not have a right to use animals for our own purposes."

This page defines the basic tenets of animal rights, discusses specieism, and argues against the uniqueness of the human species:

Basic Tenets

This case from 2015 proposes legal personhood and the right to sue in court for chimps "detained" in a zoo:

Chimpanzee Detention

The article includes several relevant outside links and a timeline of some important animal-related cases in legal history.

Famed utilitarian philosopher Peter Singer, author of ANIMAL LIBERATION, goes further than the Treehugger article in some respects but less so in others. (His position allows for meat-eating and animal experimentation in some circumstances.):

Peter Singer

He holds that "the boundary between human and 'animal' is completely arbitrary," a belief that could plausibly be extended to an argument that nonhuman animals should have the same legal rights as Homo sapiens. This debate could gain urgent practical relevance if we ever meet extraterrestrial aliens who don't look anything like us.

Margaret L. Carter

Carter's Crypt