The importance of any one of these factors varies from species to species, depending on the circumstances. Population regulation may be almost entirely due to physical factors in some populations, biological interactions in others. The first point to make is that many populations are highly dynamic and vary widely, for reasons that we don't understand. Still, the following generalizations can be made. Assumes no limitations on resources.
Some species have brief periods of exponential growth, followed by population crashes.
The rate of growth is determined by the innate capacity for increase or sometimes called the biotic potential . There are very few if any species that actually show tight, clean, logistic growth in natural situations. Commercial exploitation of natural populations often relies on an understanding of logistic growth to maximize the harvest, but it may lead to overkill. The yield is often best at low population densities, but this may make the population vulnerable. This is what appears to have happened to the passenger pigeon, and may be happening to the Blue Whale.