From all population or living creature, extinct is the ecological process. For increasing the humanity process, quantitative theory is important. It expects reliable effect from the theory. Multiple problems related to ecology are applied to influence the risk related to extinct and associated principles which informs the conservation of endangered and threatened species, habitat restoration, reserve development and design and biological control. Basic understanding of meta-population and meta-community dynamics helps in improving the understanding of extinction population.
Small animals and mammals struggles complex difficulties when compared with the big one. These species develop large body sizes over time. There are researchers who created computer models to identify the change in the process of body size of mammals. After the great efforts, they found that when the size of new species appears or produced, is larger than the size of their ancestors.
The functions an pattern of natural ecosystem in a forests, oceans, grasslands and rivers s are changed. We know very less about the size of the animal body which correlates with other species by providing the tool assessment used for extinction risk. A research is conducted which suggest that more than 27,000 vertebrate animal species are threatened with extinction.
Most of the researchers evaluate reptiles, birds, amphibians, mammals and bony fishes. It is also found that the larger species are consumed and killed by the human species. Also, on an average of 90% of threatened species are threatened by harvesting due to their large sizes. Variety of forms are taken into consideration for harvesting of large animals which include regulated and unregulated hunting, fishing and trapping for the consumption of their food i.e. meat. They also make use of their body parts for medicine and kill them for by catch which is unintentional.
Apart from all this, small animals face less threat. There are variety of small species which consists vertebrate animals with low body weight and high extinction risk. This leads to loss and modification of our habitat. Also, those small species which requires freshwater habitats are in going to the way of endangered species. It has been said that, “To address threat to both smallest and largest animals requires variety of different conservation strategies”. Large body species except mammals requires conservation attention by targeting various protection programmes.
Many ecological communities have been fundamentally re-structured due to human created activities of size and distribution related to hand and tail of the species. The previous studies say that the effects of big animals are true especially for mammals. Large species contains very good advantage of creating difficulties for the attacker to empower. It requires resources which are scarce, as large body stores more reserves. They also acquire a special ability to travel at far distances by covering a widest range for the search of the resources.it is also found that they are better heat retainers due to their travelling distance. So size is the biggest issue for the extinction of animals.