Spencer Island

Being that it was the first time that I have ever visited Spencer Island, I was lucky enough to witness the interaction of a flock of birds which seemed to be "dancing" in order to find a mate. After everyone left, Amber and I headed South of Spencer Island and we walking across a bridge. I then notice that a flock of swallows were flying around the bridge in a specific way. Amber thought that they were trying to catch bugs to eat, but after observing their patterns and their interactions with each other, I notice that certain couples were flying with each other in a way that it looked like they were dancing. Amber and I also noticed that there were swallows that had a bluish back which I assumed to be the males and some that had light brownish back which I assumed to be the females. I think that these birds ecological roles is to manage the population of insects by feeding of them and help with plants pollination. I also notice that since Spencer Island is a bigger marsh than Edmonds Marsh, there were more varieties of diversity of plants and birds. Also, with the location of Spencer Island being that the weather seems to be well balanced between sun and rain, Spencer Island seem to be more clean and clear than Edmonds marsh. One question I would ask would be: is the population of certain plants that compete over an area is the cause of some plants to be more dry and dead than other plants that are green and look healthy?