We are not sure what this particular hawk is, but we think it is a red-tailed hawk. There were actually two of them initially, but as soon as I walked outside, though I was perhaps 150' away, one of them flew away. This hawk appears to be approximately 2.5' from the top of its head to the tip of its tail and when it finally flew off, the wingspan appeared to be 4-5'. For perspective, the limb that it is perched on is about 4" in diameter. Due to the distance and the gloomy, gray skies, the picture does not do justice. Red-tailed hawks mate for life, so the two would have been mated. Perhaps they had their eye on the numerous squirrels in the neighborhood.