Hi Rich- This is a female Red-winged Blackbird. Did you notice it was quite a bit bigger than the average sparrow. The bill is blackbird-like. I'll admit it does have the overall colouration and patterning of a sparrow.
Thanks John. I never would have looked at the red-winged blackbird although the Eagle Lakes preserve I was at in Naples was full of male red-winged blackbirds. I notice many pictures of the female red- winged blackbird appear to have more pronounced black stripes than what appears to be darker brown stripes in the image I captured. Maybe its a function of age, lighting or just the angle I captured.
The nesting story of this bird is interesting. Some come early and others late to stake out territory (applies to other species too). The early ones get the best selection but too early and they can struggle with food supply. I read an interesting article on how they cooperate with each other when the territory becomes crowded. John can elaborate on this more I am sure.
Red-winged Blackbirds do have an interesting mating system and the species is heavily studied. Males hold harems of a few to many females in his territory and they nest there. He mates more or less exclusively with the females in his harem and defends them from other males. However, like most birds, I'm sure there is some "sneaky mating" going on from other males. Studies have shown that the sex ratio is often biased towards females but it's likely that even with this bias, some males in the population cannot hold a harem and do not breed in a particular year. This mating system is called polygynous (one male mates with several females), and contrasts with monogamy (one male mates with one female). By far the majority of bird species are monogamous, which contrasts markedly with the rest of the animal kingdom where polygyny is the norm. Having said this, modern genetic methods are showing that monogamy in birds is not as perfect as it seems. In many monogamous species, it has been found that chicks in a nest might be fathered by more than one male.