Update 2023-06-19: There are now many more Bird bikes than last week, so it seems to be part of a major deployment. I’m not on Bird’s email list, perhaps they have provide some info through email. I rode a Bird bike twice. They handle differently from the Lime/JUMP bikes, so as with any bike that is new to you, start out slowly until you get accustomed to it. The bikes have a digital speedometer, and they are the 15 mph limit that the city agreement enforces. They have swappable batteries, similar to but not the same at the Lime bikes. I did not ride through any of the slow or no parking zones, so don’t know if Bird has the same as Lime.

I noticed this morning that Bird Bikeshare bikes have shown up in Sacramento. The ones I saw and show up in the Bird app are in midtown, though there may be ones elsewhere. Bird devices are primarily in the central city of Sacramento, with some further out and in West Sacramento. After selecting a device, the use boundary shows up, a light blue background outlined with a blue line. Though it is more detailed, it is generally east to Power Inn Rd/Howe Ave, south to Fruitridge Rd, west to ship channel in West Sacramento, and north to El Camino Ave.
The app does not seem to have the ability that the Lime app does of selecting for just bikes or just scooters. Since the scooters are far more common, they may cover up the bike icons, and you will have to scroll around and zoom in to find bikes.
Bird has a community pricing membership for low income riders in Sacramento, 50% off rides. The access program with a low cost membership and limited free rides is not yet available in Sacramento. Bird bikes and scooters are $1 to rent and $0.49 per minute. There also seems to be a promotional 25% off.
Lime bikes, after a period of being better maintained, seem to have declined again. I rented five bikes today, and only one of them was in decent shape. All the bikes have been crashed, once to multiple times. Bent wheels, bent handlebars, loose seat posts, single gears (the old red Lime/JUMP bikes are supposed to have three gears, where as the newer white/green bikes have variable responsive gearing). I know riders are crashing bikes, mostly when drunk, but I also wonder if Lime is dumping damaged bikes into Sacramento.