We visited the Sweetwater Wetlands this weekend and had fun watching the flocks of Yellow-headed and Red-winged Blackbirds flying at dusk.
The Sweetwater Wetlands is part of Tucson's water treatment facilities and the odor can be bit daunting at first. You will probably forget about the smell since the birding is fun and the habitat is different from many other Tucson area birding locations - highly recommended.