Visit the Civic Center here in Malibu for, say, another speeding ticket a trip to the library, and you can't help notice the very busy birds making food runs between the ingenious mud nests they've built high up on the walls, and the buggy paradise of the surrounding gardens. Look closer and you'll see a mama bird clinging to the outer edge of the upper nest, feeding her brood and, no doubt, negotiating a 15 percent tip.