Most parrot-family birds fit into a biologically defined group that is referred to as K-selected Species. These mammals and birds have a long lifetime, mature slowly, have a large body size in comparison to other animals in their niche, and produce a limited number of offspring each year with intense parental care. They generally have a well defined and stable ecological niche and their young tend to stay in that niche. When all goes well, K-selected species compete well for nest sites, food sources, and other survival needs in their environment.
It is when there is a major upset in their ability to get these needs met that K-select species are in trouble. It is the mammals and birds that are classed as K-selected species that are experiencing serious declines in their populations as their habitats dwindle and/or are drastically changed. It is these mammals and birds that are becoming increasingly endangered and many perch on edge of extinction. Other K-selected species besides parrots include (but are not limited to) elephants, raptors, gorillas, penguins, whales, large trees, and (taa-dah) humans (the ones who are ruining the balance for everyone else).