I feel.like all the Dumb Beasts are the animals you might eat (cows, sheep, pigs, fish etc.) or hunt for food (stags, some bears, etc) but not for sport (lions,.foxes, etc.) whereas all the Talking Animals are ones you would not (horses, mice, ravens etc)

Posted by: @icarus

I feel.like all the Dumb Beasts are the animals you might eat (cows, sheep, pigs, fish etc.)

Not necessarily so. There's a Talking Lamb in The Last Battle. 

Posted by: @icarus

whereas all the Talking Animals are ones you would not (horses, mice, ravens etc)

As for mice, we're made aware in Prince Caspian that there were no Talking Mice in Narnia until that group of mice ate away the cords that bound Aslan to the Stone Table, and were given the gift of speech as a reward for their kindness. There's also a brief reference to Talking Rats in The Silver Chair, but we're not told whether they were given that status at the beginning of Narnia or earned it later! 

Which talking animals would you have liked to have been in Narnia that were mentioned very little? I would have liked more talking birds.  In The Voyage of the Dawn Treader the birds which brought Ramandu his food sang in a language that no one knew. But at least they were talking songbirds.  They certainly weren’t dumb beasts. There is a mention of a robin in The Lion, the Witch, and the Wardrobe, and it may have been a talking bird.  I would have liked Narnia have more songbirds such as thrushes, finches, and larks.  Lewis must have seen at least some of these while growing up in the British Isles since the area is rich in bird life. Or at least he heard their songs, and I think he would have appreciated them. There were larger talking birds such as eagles and owls in Narnia and they were beautiful, but of course they were not songbirds.  I could easily imagine Lewis joining a group to protect birds such as the Audubon Society or a similar organization if he were living today. I think he definitely appreciated birds.  🙂

Posted by: @narnian78

I could easily imagine Lewis joining a group to protect birds such as the Audubon Society or a similar organization if he were living today. I think he definitely appreciated birds.  🙂

We do have an organisation like that in the UK — the Royal Society for the Protection of Birds (RSPB), founded in 1889 — and as far as I know, C.S. Lewis was never a member of it and isn't known to have shown any particular interest in it or in similar groups.

It would be nice to have talking songbirds featured in the Narnia books, but just because they're not mentioned specifically in the narrative doesn't mean they didn't exist (and there's certainly nothing to say they didn't). I'm guessing that if any children had written to Lewis asking if there were talking songbirds in Narnia, he would probably have said something similar to what he often suggested to his young fans — "Why don't you write some stories of your own about them?"  

There were no talking reptiles. I think being warm-blooded was a requirement. 

@courtenay 

I have heard of that organization before, and I am guessing that there are others protecting birds and other wildlife since a single group of people cannot do everything for conservation.  There are probably more conservation groups in the UK today than there were in Lewis’ time. Here in the US we have the National Wildlife Federation and American Bird Conservancy besides Audubon. They protect non talking birds and animals, which Lewis would have considered a good thing.  If Lewis were living today with the need to save wildlife habitat which is disappearing he probably would have supported conservation groups. The Narnia books show his love for nature and its creation by Aslan. Saving the wildlife habitat was very important to him.