There's a certain sort of bias against animals that seems clearly pernicious and bears a strong resemblance to racism and sexism. This is the sort where animals are immediately dismissed because of surface characteristics--"They're just animals". In contrast, there's the idea that humans should have some sort of priority in our decision-making, most of the time. This sort of prioritizing is widely assumed, even by advocates for animals. It's the sort of prioritizing you do when, after a natural disaster, you worry first about the people affected, and only later (if at all) about squirrels and rats. It's the prioritizing that would allow you to survive in the wilderness by killing animals if your vegetarian provisions got lost. I don't think this sort of prioritizing has any connection to nasty, groundless attitudes like sexism and racism. But ... how to defend it? What's it based on, such that it's not just another nasty prejudice?
There are two approaches. One is say that animals are different from humans in such a way that they deserve less in some specific circumstances. This is what Peter Singer says when he admits that animals have a weaker interest in going on living than humans do--since they have far fewer preferences about their futures. So even if we do owe equal consideration to their equal interests, their interests are often not equal to ours. On the more traditional, less animal-concerned end of the ethics spectrum, there are those (like Kant) who think animals can't be owed anything at all, because they are missing the preconditions for moral considerability. Animals are on the outside of the moral community, for lack of this or that special characteristic.
The other approach is to say "It's not about the animals" (in so many words). Rather, there's something about co-membership in one community, partly defined by species, that makes conspecifics have special duties to each other, and weaker duties to outsiders. On this approach, even super-smart aliens would be second priority, if they happened to land just before a natural disaster or we needed them for some type of resource. And even not-so-smart conspecifics would be first priority, like anyone else.
In my book Animalkind I take both approaches (in chapters 5 and 6), but start with the first. Maybe, though, that was a mistake. Perhaps it's more fundamental to understand what's morally important about two individuals being conspecifics, such that some degree of prioritizing each other, at least in some situations, is perfectly appropriate, and unlike mutual support among racists or sexists. The challenge is to explain why prioritizing conspecifics is not like prioritizing members of your own race or sex.
Surely (my intuitions tell me) it's not. Roll back to primormordial folks living in harsh conditions. It's OK when a tribe decides to save itself in a harsh winter and doesn't expend equal energy checking on the welfare of rabbits and wolves in their burrows and dens. In fact, for the sake of survival, you can even kill rabbits and wolves, and this is a much better idea than conspecifics killing each other. If I look at a rabbit as potential food, but not my neighbor, that can't, just can't, put me in the same category as a racist or sexist! So my intuitions tell me, but why? Why is it morally respectable for humans at least in situations of scarcity and hardship to see other humans as "in-group" and wild animals as "out-group"? (Leave aside pets, who are honorary family members, and can only confuse our thinking about these issues.) What would be a respectable way to explain yourself, if you would never eat a baby to survive, but you would eat a rabbit?
Well, there are the facts of life. I can reproduce with other humans, but not with animals. I can enjoy certain kinds of friendship with humans, but not with animals. The survival of my species in the future feels to me like my survival, but not so, the survival of rabbits and wolves. The problems of conspecifics seem like my problems, but less so the problems of others. These seem like unchangeable and innocent parts of human psychology--nothing at all like the various insidious attitudes that lurk in sexists and racists. If this be speciesism, then we've got to distinguish between malignant speciesism and benign speciesism.
To put it another way, I'm skeptical that "the expanding circle" should expand in such a way that animals are not just members of the moral community (they count, we have duties to them), but there are no longer any respectable boundaries between groups. It's respectable (I think) that caribou in a herd care about each other in a way they don't care about wolves; and it's respectable that the humans in a community care about each other in a way they don't care about caribou or wolves.
Animal advocates sometimes erect more powerful moral principles than needed, to argue against the worst, most flagrantly speciesist abuse of animals. To counter extreme cruelty, they ask us to pretend there is exactly one moral community, with no lines at all between groups. But nobody really thinks this--we believe in lines even between different families and different nationalities, let alone different species. We need to allow for certain kinds of groupishness, but without descending to the level of the virulent speciesist. We can see the human community as "one nation" in some ways, with animals on the outside, without descending to the cruelty of the animal abuser or factory farmer.
Groupishness. What is it, what's good about it, when is it bad....? Discuss.