Also, I was checking them out just now (that's when I noticed the absence of one baby) and the male put his head down and hissed at me as they do. I didn't approach any closer, just stood and watched. They crossed over the little roadway next to my place to another grassy area where there were another pair of adult birds. The father put his head down, extended neck and chased of after them. He spent a good twenty or thirty seconds driving the other birds off. my question is why would he bother doing that, what threat would those other two Woodies pose?