The tendency to watch one's environment and others in it for cues as to how to act in particular situations is called self - monitoring.
Answer :
The theme of "A Complication or Two" is that chance results in greater fortune than careful planning.
The narrator carefully constructs this theme throughout the story. The narrator had made a grand ten year plan for his future education, starting from an Ivy League School of choice to a Law School. However, fate had other plans for him and the role of fate started when he received his rejection letter from his preferred Ivy League School. He opted for some more volunteer service at Tri-Valley Hospital where he met his future university mate and wife, Alma . Coincidentally, he also landed a residency at Tri-Valley Hospital after clearing medical school. If he had received an acceptance letter from his parents' alma mater he would not have opted for more volunteering service and would not have met his wife of thirty years or landed the residency at Tri-Valley Hospital.
The following lines from "A Complication or Two" describe the role chance or fate plays in life :
"Looking back, I suppose my life started with that letter. I don’t think everything necessarily happens for a reason—there’s too much tragedy in the world for that. But there’s no doubt that some misfortunes turn into pivotal moments that can alter the course of a person’s life for the better. Alma and I have been together for 30 years now, and I still wonder what that other life—the one in which my letter said “congratulations”—might look like. I expect it would have been pretty grand, full of its own triumphs and pitfalls. "
A few would be maybe a change in mating? Like if the animal isn't leaving it's habitat to go and get nutrition and mate then something might be off with the animal, or the seasons are messing them up due to weather.
Another would be possibly be animals who usually don't go into competition, going into it with animals that are usually in a good zone, most likely due to food dropping or habitat population increase.
And then there's invasive species, they come in and kill off animal species causing a whole environmental habitat of animals to die off, eat their food and take in all the nutrients, and then possibly animals having to go off and find a new habitat causing them to become invasive species.
