The Red-winged Blackbird is one of the most abundant birds in North America. The male is silky black with red and yellow shoulder patches that he can either display or hide depending on his mood. Females have brown streaks, similar to a dark sparrow. Above a male doing the splits on reeds at Agua Caliente in Tucson, and below, two images of a male in mating season (March 2017) at Sweetwater Wetlands. The male is calling out to impress nearby females, and to defend his territory. He is making a lot of noise, trying to look very large and fierce!
We know that crowd estimates are tough, but below must be hundreds of blackbirds taking off from their nighttime huddle at Bosque del Apache in New Mexico in January of 2016. A Sandhill Crane is in the foreground. The three images below show progressively more detail. I suspect these are mixed male and female Red-winged Blackbirds, with some Yellow-headed Blackbirds mixed in.