Rays In The Creek

That's not a euphemism for anything ... it's something that I saw this weekend with my wife and kid, off of the bike path in Corte Madera. For those who don't know the area, while it's connected to the San Francisco bay, it's definitely inland, and any access to the bay itself is nowhere close. So, to see a MANTA RAY - and we actually saw two of them - was beyond weird.

My wife said, "If I hadn't been here with you, there's no way I'd believe it." And I felt much the same way. (Our kid? She thought it was cool. Also? She's four.) So, I hit up the internet and lo and behold, YouTube to the rescue:

[youtube https://www.youtube.com/watch?v=9RKTnoUumJ4?rel=0]

So, here's my question -- why is it there? I asked friends at a party the next day, and there was quite a lot of thought, perhaps, that the rays had come in there to lay eggs (and then, all of us adults with multiple degrees wondered if rays actually laid eggs to give birth). Um, nope. They have live births. Thanks, Wikipedia! And actually, that link is for a manta ray because yet again, none of us seemed to realize that manta rays only exist in warmer climates. This is likely a bat ray. Shame on us, over-educated adults!)

But still, perhaps they came here to give birth and either can't get out or don't want to?

I'm fairly sure this isn't normal, so I'm wondering ... what's going on?