Burrowing Owl Update: See below
This Great Blue perched on a rock at the water’s edge opposite the hotel. It just stood there, looking around now and then, not hunting. Then it hopped off its little island rock and began an elaborate multi-stage exit. First it climbed ever so slowly and deliberately up the slope to the dirt path. In the early morning hour no people, pets, or bicycles passed to disturb it. After standing quietly and looking around, the big bird ejected a poop — an uncommon sight — and croaked a couple of times, for no obvious reason. Then it took wing across the street and perched in one of the cedar trees at the edge of the hotel parking lot. There it fought off a pair of annoying crows, and that done, took wing and flew off across the hotel lot to the south.
The heron’s route resembled that of the bird I posted on October 13, “Blue v. Crow.” Unfortunately I did not get any closeup shots of the earlier heron for comparison. They vary quite a bit in the head, particularly in the beak. It’s possible to make credible guesses about individual identification.
Note that the heron’s poop is a jet of white liquid. Unlike mammals, the avian digestive system does not process solid and liquid matter in separate streams. Digestible solid matter, like rodent or fish bones, gets ground up in the gizzard and processed with digestive acids into a liquid that the bird ejects via its cloaca, the analog of the mammalian rectum. The main digestive fluid is uric acid, which is white. Hence the white tracks that birds leave behind in their perching sites. Indigestible solid matter, such as animal hair, gets compacted into a pellet that the bird coughs up or regurgitates via its throat. This is what the heron does. So do many other species. You can see an example with a Burrowing Owl and its pellet in the movie “The Owls Came Back.” Read more about bird digestive systems in Wikipedia.
Burrowing Owl Update
The Burrowing Owl that I posted yesterday evening was still present this morning. Its perch is extremely difficult to spot. By raising my tripod to its full extension I was able to get this headshot. The owl disappears from view completely if it moves even a few inches to either side.