Ecology examines the interactions between organisms and their environment across multiple levels. At the ecosystem level, studies look at how communities interact with their physical environment. Organism level studies focus on individuals and their physiology or behavior. A species' niche represents its unique relationship with its environment in terms of factors like temperature, salinity, and pH. Population ecology studies populations in relation to their environment and how environmental influences impact population size, density, and age structure. Species exhibit different life history strategies like semelparity where they reproduce once and then die. Interactions between populations in a community can be beneficial, negative, or involve predation, parasitism, and herbivory. Aposematic coloration warns predators while cryptic color