Mystery on Haight Street

The following is a bizarre bit of city life not for the faint of heart. It dates to this past spring, while I was still living in Upper Haight:

I was walking to Haight (at my usual double-time) and unconsciously stepped over something (like a seasoned San Fransican). Out of the corner of my eye, I noted that it wasn't the usual pee stain, turd or bar puke. Indeed, it was about a two foot long strip of ambiguous brown goo, and right next to it was a dead baby bird. I've passed this apparition a few more times in the course of the last couple days, and a certain morbid curiosity has gnawed at the back of my mind. What could have possibly made such a singular assemblage? Perhaps Sherlock Holmes has finally gone to my head.

In any case, when passing it this evening something clicked and I think I finally have an explanation for it. I'd assumed the strip to be diarrhea and couldn't place the bird into any kind of narrative and certainly I couldn't think of a plausible way that diarrhea could be laid out so evenly and in such a straight line. The bird did suggest one of the crusties' dogs was somehow involved, though.The bird was at the age that it probably had fallen out of the nest while testing its wings. My epiphany was that the goo wasn't diarrhea-- it was vomit!

One of the crusties' dogs must have swallowed the marooned baby bird whole in its eagerness. Then, the bird, whether through struggling or just because it was pointy and feathery, caused the dog to vomit. But not just any vomit-- projectile vomit. The unusually dark color and smooth consistency of the vomit can be explained by an atypical, homeless-person's-dog diet. I'm not sure what would cause this though, maybe pure meat? Or kale, perhaps?