The youth group from First Unitarian spent Friday night visiting the youth group at the Nantucket Unitarian Universalist church. It’s a two-hour ferry ride out to Nantucket Island, and I spent most of the time on the upper deck, binoculars glued to my eyes, looking for birds. I saw dozens of Common Loons spread out over Nantucket Sound, looking very beautiful in their summer plumage; the ferry passed close enough to three of them that I could hear them calling to one another with that weird ululating sound they make. I watched Common Terns catching fish: cruising along until they spotted something; hovering for a moment; then plunging suddenly into the water, thrashing around, and more often than not flying up again with something clamped in their bill.

Then out of nowhere, a fast, dark bird flew at one of the terns, swooping up on the tern from underneath. It was a Parasitic Jaeger (Stercorarius parasiticus), a bird that eats fish it can steal from terns and gulls. The jaeger attacked the tern again; I didn’t see what happened, but there was another birder on the boat who said that it looked like the tern gave up, dropped the fish so the jaeger couldn’t get it, and thus avoided being harassed any further.

I was tempted to think ill of the Parasitic Jaeger for being parasitic. From my moral frame of reference, I didn’t like the fact that one bird was stealing food from another bird. Yet when I thought a little more, I realized that I am quite happy to eat other mammals, and I don’t worry too much about the way my human needs destroy the habitat of other mammals — surely what I do to other mammals is more reprehensible, morally speaking, than the jaeger stealing an occasional meal from another bird. Nor am I entirely sure how to apply moral judgements across species boundaries — is swatting a mosquito the same, morally speaking, as killing another human being?

Even after thinking about it in this way, I still didn’t much like the Parasitic Jaeger; clearly my human morality lacks logical consistency. Whatever my moral feelings, it was quite something to watch the jaeger swoop up and harass the tern; it was, in its own way, spectacular and even beautiful.