The given blank can be filled with Consumer.
In an ecosystem, the producers are the members, who are make their own food by using sunlight. Mainly the green plants are the producers, they produce their own food by the process of photosynthesis.
The consumers are the organisms, who consume the food made by the producers. The source of energy for these organisms are the producers. The energy from producers is transferred to the consumers. So, energy always flows from producers to consumers.
The form of animal behavior that this prairie dog on guard duty exhibits is altruistic behavior.
This means that the dog isn't only thinking about itself, but rather about the others as well. Since it escaped danger, it alarmed other dogs as well, so that they could also be safe and not injured by the golden eagle. It seems that not only humans, but also animals are capable of showing such a behavior.
The process is called Peer-Reviewing. In Peer-Reviewing, scientists/academic peers "peer review" the work of a scientist to check for accuracy or any false information that might reduce the legitimacy of their study or change "how realistic/real" their study is.
p.s. This is also common sense because scientists make up an entire scientific community who base their scientific studies on consistency and accuracy.
