The peace garden at Lake Harriet is just that: a trickle of waterfall and stones etched with one-word philosophies that offer solace and refuge. The rose garden is just that: a cornucopia of quiet, explosive beauty. And the 13-acre bird sanctuary that sits tucked behind the two is just that: a haven where we go to see warblers, vireos, woodpeckers, soras, and great blue herons, not to mention all the binocular-wielding humans they attract, like monks to a flame. Now, shush. What's that up in that fir tree, by the branch that looks like a slingshot?