Moral Agency and Moral Considerability: Do Animals have these?

I have done a Google search, and found that I can't find a good summary of two academically-oriented papers on crucial questions for ethics, namely, "Can non-human animals have ethics?" and "How should we treat non-human organisms?" Here's such a summary, taken from my on-line syllabus (I retired in 2005) in bioethics.

Richard A. Watson and Moral Agency
A Summary of Richard A. Watson's "Self-Consciousness and the Rights of Nonhuman Animals and Nature" (Environmental Ethics 1:99-129, Summer 1979. Also see Google Books for the article on-line.):

Moral Agency
Rights don't make sense unless the entity granted rights can also fulfill reciprocal duties. The Golden Rule suggests reciprocation as an ideal. So does Kant's Categorical imperative (Act only in ways that could be adopted as general moral principles).
To earn rights, one must be a moral agent--an entity capable of performing moral duties, and, in fact, carrying out these duties.
The requirements for moral agency, Watson writes, are:
(1) self-consciousness,
(2) capability of understanding moral principles about rights and duties,
(3) freedom to act either according to or opposed to given principles of duty,
(4) understanding of given principles of duty,
(5) physical capability (or potentiality) of acting according to duty, and
(6) intention to act according to or opposed to given principles of duty. (p. 101)
Moral agents can act opposed to duty. This does not make them any less a moral agent, but may cause them to be deprived of certain rights.
Humans can assign rights to corporations, animals, etc., but that does not make such an entity a moral agent.
(The Wikipedia has an article on moral agency, but the Wikipedia, itself, claims that the article has some serious weaknesses.)

Four arguments for giving rights to nonhuman animals and nature
1. Ecological. If something is part of the living world, it has a right to exist.
Watson disagrees with this, and with Leopold's Land Ethic, because it is deriving value from fact, ought from is.
2. Prudential. We should treat animals as if they had rights, so that we won't treat humans like we treat animals.
Watson says that this just says treat animals as if they had rights, which is not the same thing as saying that they do.
3. Sentimental. Sentience (conscious of sense impressions) imparts rights.
Watson says "why?" The animal rights movement, he says, hasn't really proved anything. They are asking us to help animals avoid unnecessary suffering. He agrees, but doesn't agree that animals have rights. We have a duty not to cause needless suffering.
4. Contractual. Human beings should treat the property of other human beings as if it had rights.
Corporations are not responsible, he says. Humans are, and one of their duties may be to treat a corporation, or an animal, as if it had rights, but that is not the same as saying that they do have rights.

Self-Consciousness and Moral Agency
The author says that some chimpanzees (and presumably bonobos-that species wasn't recognized when the article was written), gorillas (probably orangutans and perhaps gibbons), dolphins, (probably whales), elephants, dogs, pigs, and maybe cats and some other animals are sometimes moral agents. That is, there is adequate behavioral evidence that they have self-consciousness, capability of understanding moral principles, free will, understanding of specific duties, physical capability, and sometimes the intent to act with respect to moral principles. Frans de Waal has argued, here, and in his books, such as Primates and Philosophers: How Morality Evolved, that there is evidence that non-human primates have a moral sense.

Moral Considerability
An article by Kenneth Goodpaster in the Journal of Philosophy, 75:308-325, 1978, "On Being Morally Considerable," examines the question "What sort of entities must be taken into account in making moral decisions?" Goodpaster's answer, in brief, is "living things."
Why? Because, he says, they have interests, that is, things that they need. He includes water for plants as an example. Goodpaster does not claim that we cannot kill plants, or even animals, for food, or that we can't do research on them, or that we can't protect ourselves against harm from them (for example by pulling weeds from a garden) but says that we must consider the interests of other living things when we are making decisions that would affect them.
W Murray Hunt criticized Goodpaster in an article in Environmental Ethics (2:59-65, 1980) "Are Mere Things Morally Considerable?" Hunt suggested that inanimate objects might also be given moral considerability. Goodpaster replied, in part as follows: "I continue to believe that "being alive" is the only plausible and nonarbitrary criterion of moral considerability." Kenneth E. Goodpaster, "On Stopping at Everything: A Reply to W. M. Hunt," Environmental Ethics 3:281-284, Fall 1980. Quote is from p. 284. He also quoted Joel Feinberg ("The Rights of Animals and Unborn Generations," in William T. Blackstone, Ed., Philosophy and Environmental Crisis, Athens: University of Georgia Press, 1978, p. 51) as saying that "a being without interests is a being that is incapable of being harmed or benefited, having no good or 'sake' or its own . . . a being without interests has no 'behalf' to act in, and no 'sake to act for." (quoted on p. 282 of Goodpaster)

Thanks for reading. I hope this may be useful to someone.