Little to no moisture in the air and the hot temperature instantly evaporates water. Of course there is one problem I do have with both Sunlight and Harsh Sunlight weakening/nullifying Water-type moves: why aren't Ice-type move affected? Like for some moves you could just say its concentrated coldness (let's just assume that makes sense in the physics of the Pokemon world) but there are some which is frozen water.
Oh joy, I get to SCIENCE!
And my answer is thermal resistance. You see, no matter how great the difference between a really hot and a really cold object are, there's an overall limit to how fast heat can flow from one body to another, determined by the material's thermal resistance. To experiment, try putting a piece of frozen chicken on the stove. No matter what you set the burner to, let's say 200 F versus 425 F, after a minute the chicken will still be mostly frozen inside (also known as the Chef's Fallacy). That's why you are supposed to de-thaw it hours in advance.
And solid water, or ice and snow, is an insulator, so it has a higher than average thermal resistance. You might see the surface melt instantly, but the core of your Icicle Crash attack will be mostly intact after a few seconds of exposure. Ever notice how large snow piles linger days after the temperature rises, while water puddles disappear in a matter of hours? Liquid water in contrast is a heat sink, it absorbs heat really well.
The only real way to overcome thermal resistance is increase the exposed surface area, which is another reason why water attacks evaporate and ice one's don't. Most water attacks are completely exposed or lack "depth" to them, increasing thermal flow rate. Now, this would mean that attacks like Powdered Snow shouldn't work while Ice Ball and Icicle Crash would be fine, but no theory is perfect.
Gee, that thermodynamics class I took is worth it's weight in gold.
Pidgey represent pigeons yes? This means they behave like them so they like being fed. If you feed a pigeon too much they are known to get this large. I know this because I have fat pigeons in my garden so this picture reminded me of that.
It was just a little joke, but since you brought it up, that episode (
Fly Me to the Moon) was referencing an observed phenomena for some island birds that lack predators but have abundant food supplies. In some of these cases, the birds "de-volve" becoming fatter and flightless (like the Kakapo, a flightless parrot on one island off the coast of New Zealand). So basically what you said, just without any human causing it, just no predators and lots of food.
It's actually really clever of the anime to use that in a story, and in fact I really love this episode. Orville the pidgey overcoming genetic predisposition and Wilbur the human having to teach the bird how to fly himself using a hang-glider was pretty touching, and the final scene of Meowth asking Orville about space was really sweet. Just a surprisingly complex and thought provoking episode from an otherwise mediocre anime (and Johto is thought to be one of the weaker seasons!)
...plus Orville's little flight cap is really cute.
fly me to the moon, let me play among the stars...
