Mfcttrf

There are a lot of interesting things in nature, but of all land vertebrates, birding has highly disproportionate attention. People (perhaps including birding enthusiasts) may note and appreciate mammals they see, and reptiles, but birding stands on its own as a hobby.

Why, about birds and about us, are we so interested in birding?

I can imagine a partial answer in that birds are more interestingly likely to fly in and out of an area one is observing, and that birds are often brightly colored, but this is a guess on my part, and I would give them only a guess's degree of probability.

Why emphasize birding?

This is rather speculative, but draws on a few birding/wildlife books I've read and it's too much for a comment. It also has a little UK bias, but I've visited 4 continents on wildlife trips, and much of this seems universal.

First, to get them out of the way: invertebrates may be interesting but in the general population there's a bit of a "yuck factor". Only butterflies (and maybe bees) really have much general appeal. I do know a couple of people who are as keen on their lepidoptera as birders are on their aves.

Mammals are broadly interesting. They're what people with only a passing interest in wildlife go on safari, or to the zoo, to see (along with the largest reptiles). But for many people, especially city dwellers, sightings of wild mammals are rare. The creatures themselves are, and they're often nocturnal. I'm in a village and cycle at dawn and dusk, so see more than most, but still only see (introduced) grey squirrels and rabbits regularly, with deer and foxes occasionally, and badgers/weasels almost never. Rats have the yuck factor again for many people, and are to be avoided, while most people will only see smaller rodents if they've got a cat to bring them in. So to see interesting mammals takes effort. Much of this applies to reptiles/amphibians too.

Birds on the other hand are visible, audible, and common. Having a few different attractive species visible from your own home is normal. Some (e.g. European Robins in the UK) approach close enough that you can really appreciate them, while others draw attention to themselves at a distance by singing - and birdsong is generally pleasant. If you have the beginnings of an interest in wildlife, it's most likely to be revealed by garden or local birds. Then we have a self fulfilling effect - people are interested in birds, so they go to bird reserves, which means there are facilities for people to go to.

It's also a case of accessibility, birding really doesn't take any special equipment beyond say a pair of binoculars and birds will visit peoples backyards and bird feeders. While mammals can be shy or limited in area requiring trips to see them. Fish take special equipment to catch and mammals especially the biggers ones can often be dangerous to humans.

The next thing is there are tons of diversity among the birds you can see while there is a much smaller number of mammals compared to birds, compare this list of birds to this list of mammals.

This also may depend on where you are, it is faily common in national parks in the U.S. to have massive elk/moose/buffalo/bear traffic jams and I doubt that you would ever see that for a bird.