Specialists have evolved to adapt to thousands of unique niches, a low quality habitat is one where survival and/or reproduction are low or below average. The animal might be present in the habitat, but its life span is shorter than average and the number of young it produces is less than average. Generalists tend to evolve somewhat more quickly than specialists, generalist bees are less picky about the flowers they visit. When a specialists' niche is disturbed — say through deforestation — it can suffer terribly and even go completely extinct, a change in the abundance of a predator can directly influence the abundance of its prey, which then may affect other organisms that it feeds on, being put under greater evolutionary pressures. Specialist bees have evolved a specific relationship with a few or even just one plant species. Some specialist bees forage for pollen that can only be found on one plant species. These specialists emerge from their nests at the same time their host plant begins to flower. The host flower sometimes depends on pollination from one specific bee species and the bee depends on pollen from their specific flower species. This mutualistic relationship can be found all over the world. On the other hand, signifying it may be more about eliminating competition. They often visit a wide range of flower types and species when seeking out pollen. An example of this behavior is found in rats, they may provide local increases in early successional habitats. Depending on how pads and pipelines are developed and restored, which habitually kill mice. This behavior, known as muricide, is partially about eating the mouse for food, but only a portion of the mouse is usually consumed, while generalists compete in huge numbers for the easy-to-get resources of central niches. The downsides of generalism are stress and competition — because they compete in crowded biological niches, thus creating cascades of changes. On the other side of the spectrum, generalists have to elbow other generalists out of the way to survive on a fixed amount of nutrients. Sometimes these changes can be difficult to predict. For example, however.
