Portland’s Tom McCall Waterfront Park erupted Tuesday when Gerald, a 300-year-old oak who learned to walk last month, squared off against Brutus, a towering azure waterfowl claiming kinship with Big Bird. The three-hour standoff over prime bird feeder frontage drew hundreds. “I’ve been rooted here since before Lewis and Clark, and this oversized parakeet wants my squirrels?” Gerald bellowed, bark legs creaking. Brutus answered with honks described as “a fog horn having an existential crisis,” then pecked Gerald’s lower branches as the tree fired acorns with sniper precision. Park rangers, whose manuals lack a “mobile flora” chapter, tried a megaphone, then retreated. A attempted “root slam” by Gerald was foiled by Brutus’s nimble aerial dodges. “Classic ambulatory territorial syndrome,” panted botanist Dr. Evelyn Marsh. Ornithologist Dr. James Fletcher cited “waterfowl displacement anxiety, at unusual magnitude.” City Hall mediation began Wednesday. Gerald barely fit through the doors; Brutus perched on a reinforced chair. The sticking point is exclusive squirrel-watching rights. Officials posted “Interspecies Territorial Dispute Zone” signs as vendors sold “Team Gerald” and “Team Brutus” shirts. “Inclusive of all residents, root system or wingspan,” vowed the mayor.