Tuesday, April 28, 2009

A Goose with a View

While poking around in the woods next to the C & O Canal towpath for a good photo of Virginia Bluebells, I disturbed this Canada Goose (branta canadensis). He was immediately on the alert, honking in a threatening way, and eyeing me with suspicion. Movement above by his mate drew my eye to the top of the old railway support.

The female goose peered over the edge of the concrete to see what the ruckus was about but didn't move from her spot. I guessed she was nesting on the top of the structure.

The goslings are going to have quite a drop when they are ready to venture forth. But you have to admire this mama's ambitious choice of site. The eggs should be well protected from skunks or raccoons. However, crows and ravens also consider goose eggs a tasty tidbit--might the eggs be more exposed in this spot? Once the goslings leave the nest, (if they survive the drop) the Potomac is a short stumble down a bank and they will be waterborne.

Typically the female Canada goose chooses the nesting site, builds the nest and lays the eggs, while the male defends the territory from other animals including other geese. Isolated spots with good visibility are preferred. Despite being trailside, this pair's nest is over 10 miles down the towpath from Williamsport, with a grand view of the river and any cyclists or nosy amateur naturalists approaching from either direction.

Canada goose nests are not elaborate and are rather quickly thrown together: weeds, twigs, pine needles, grass or moss are assembled in a mound then rounded out and molded into shape by the goose's body as she nestles in. The average clutch has five eggs but might include up to nine. It would have been fun to watch the nest building process at this spot.

Canada geese are monogamous and most pairs mate for life. Life spans can range to over twenty years. I wonder if this pair has successfully nested here before. If so, do the other geese recognize that they have "dibs" on this site? Or perhaps they are upwardly mobile newly-weds producing their first brood. They remind me of the red-tailed hawks who famously nested high above New York's Central Park adjacent to Woody Allen's penthouse--with their very own 'deluxe apartment in the sky.'

Saturday, April 4, 2009

Up Close and Personal with a Jumping Spider

Nature is everywhere if you only look. I took a brief walk in the city park at lunch. This spider was hanging out on the garden gate next to the museum. A baby spider was rappeling down from the lock on a strand of silk. The spider here was perhaps the doting mama.

Jumping spiders (Family Salticidae) are easily distinguished from other spiders by their four big eyes on the face and four smaller eyes on top of the head. Around the world there are probably more than 5000 species of jumping spiders.
I leaned in close for a better look. Instead of trying to hide, the spider turned to look directly up at me. I could see its eyes and furry whiskers. It appeared as interested in me as I was in it. Our eyes locked. Here is what I saw.

I had never felt "seen" by a spider before. I felt disoriented as if the tiny world of the spider had suddenly expanded and I had shrunk to the spider's size. It seemed some sort of communication passed between us.

The spider's behavior made sense when I later learned that jumping spiders have much better eyesight than other spiders and most, if not all, insects. Jumping spiders' large pair of eyes in the center front give them excellent color vision and a high degree of resolution. Even more amazing, the shape of their retinae indicates they may have telephoto vision. I was looking at a hunter with some high tech equipment!

Jumping spiders can spot and stalk insects from long distances. Their excellent vision is also an important part of their 'interspecies' communication, particularly in courtship. Males dance before females, displaying contrasting or brightly colored markings on their bodies.

The caption for the photo of one jumping spider that I found on the 'web' said that it lived in the space between the photographer's gate and fence post in his back yard. And here was "my" spider frequenting the same "habitat." Imagine all the humans who walk through this gate, oblivious to the ferocious sentry on watch!

When I returned to my office and sat down at my desk, a baby jumping spider about a third the size of mom appeared in my lap. It must have hitched a ride on my pants' leg while I was transfixed by its parent's gaze. Somehow even a spider baby is cute. I attempted to slide it onto a post-it note but it sprang onto my thumb. I released the baby out of my window to fall onto the grass below. It had traveled in my car with me and was now several blocks away from the park. Happy hunting, little spidey!