09/09/2013 10:08 am ET Updated Nov 09, 2013

Flying on the Umwelt

On Wednesday Allen Fish and I talk umwelt up at Hawk Hill. Fish is the director of the Golden Gate Raptor Observatory and commandante of its annual hawk watch - in which more than 300 volunteers cycle through shifts to daily count raptors commuting across the Golden Gate Bridge on their Southern migration. While Fish takes passionate exception to anyone who might characterize hawks as mystical, regal, majestic, transcendent, and so forth - "that's all about us," he says, "and thinking about the birds that way has never done them any good" - he nevertheless has quite the poetic side and it's fun to muse on life's big questions with him.

We didn't exactly use the term umwelt, which has some pretty specific connotations in the world of semiotics, but which is also colloquially useful to describe the felt thisness of the world. Fish and I discuss how every generation has a sense of what nature is based on what's there when they look at it. "Think about what this place looked like before the city was built, a couple of hundred years ago," Fish says. We don't know what's been lost because we didn't watch it go. "If we knew we'd probably weep."

I started with Fish's hawk watch last year as part of my research for a book I'm tentatively calling Citizen Scientist. (I may call it Citizen Science. Or maybe some variation of The Snake, the Seeker and the Smartphone, which Ken-Ichi Ueda came up with. Kibbitzing on this subject is most welcome.) So - although I'm watching for hawks, I'm also watching the watchers. With raptors, this gets deep, because these "birds of prey" are also constantly watching. In fact, one of my favorite sights is a gliding hawk with its head at a 90-degree angle to its body - a model of absolute focus on the ground and what little critter might be moving across it.

Hawkwatching is a crazy, cosmic, exhilarating, and exhausting activity. Wednesday we count more than 250 birds over about a six and a half hour period. Long stretches of time go by with no birds. Then someone calls out, "juvenile red-tail North," and then there are four birds and then suddenly you are choosing to keep your binoculars on just one because sun is refracting through its wings and you can really see its thisness, the fact that it is yes a juvenile red-tail and not an adult red-shouldered, for example.

All last year I watched and wondered, why hawks? There are so many gorgeous birds out there, and no lack of bird-lovers, but the group at Hawk Hill are raptor-bent. Wednesday I slap myself on the head for ever asking this ridiculous question. Hawks most beautifully dart and glide and swoop and then shudder a moment, wings gathered then extended again. Ravens and crows do a fun dance but it isn't as pretty. Hawks appear to be darning up the sky and making its fabric. That's no mystical, regal, transcendent thought - it's a biological observation. Hawks are top predators so have an outsized impact on the rest of the food chain. Most obviously, they keep rodent populations in check. They are sky-dwellers but their impact extends to the geological carbon cycle, which is created partly through food-web interactions, partly through the abiotic cycle of uplift and erosion that gives us ground. Hawks stitch earth and air together.

There's a lot to see from Hawk Hill, including the peregrinations of fog over the water. Sunlight reflecting striated on the bay momentarily assumes a pattern that looks just like the orderly mottle of the hawk's wings. "We have no trouble understanding that plants, animals, insects, birds, are all products of and reflect the environment," Fish notes. "But we keep ourselves separate from that." He laughs at the absurd disconnect. "We don't understand that we look like we do and even think like we do because we're part of the world, its evolution." That's umwelt for you.

Mary Ellen Hannibal will be giving a presentation on The Spine of the Continent at Book Passage in Corte Madera, California on Saturday, September 7 at 4 p.m. Free.