An anti-Thoreauvian sojourn in the Canadian wilds turns eco- lyricism on its head by spurring an iconoclastic tribute to the big bad city's natural charms. Siebert, a poet and essayist whose work has appeared in the New Yorker, Esquire, and elsewhere, proves you can take the boy out of the city but you can't take the city out of the boy. Regularly lulled to sleep by gunfire and car alarms in his Brooklyn neighborhood, he spends his first night in a ramshackle wilderness cabin with lights on, ax in hand. Throughout his summer at Wickerby--the family hideaway of his ``near-wife,'' Bex, whose absence he's come north to brood upon--he remains a reluctant naturalist, not luxuriating in isolation so much as surviving it. His narrative of the season, written as a kind of extended entry in the ongoing Wickerby journal, switches back and forth between the cabin and his Crown Heights apartment, between escape and return. Both natural and man-made wonders attract Siebert's spare, descriptive prose (``the loud, waxen-winged scatter of a rooftop crow, like a broken fleck of night sky''; ``the unsprocketed flicker of subways through bridge trellises''), but it's the city that most vividly engages his intellect: He seems to have fled civilization chiefly to perceive it more clearly. Some invocations of superior urban splendor are laughable--``A city wears the changing seasons with more ardor than the country: the isolate blossoms, the thin sweetness of thawing cement''--but meditations on the senseless slaughter of polar bears at the Brooklyn Zoo, the activities of rooftop pigeon keepers, and the grand, unfulfilled vision landscape architects Olmsted and Vaux entertained for Prospect Park form a discursive but profound commentary on our conflicting impulses to connect with and subdue nature. A welcome departure from reverent naturalism, Wickerby survives its sillier moments on the strength of Siebert's fine writing and keen eye for beauty in the margins.