Endangered species will sometimes require assistance from man to survive, even though, ironically, man may have been a major reason for their decline. Breeding programs have often been successful, with animals such as the Arabian oryx being saved from extinction. Any breeding program should begin when there are signs that a species is declining alarmingly -- even if it is not near to extinction. Taking action at an early stage will also mean that there will be a bigger and healthier gene pool to choose from.
Regular studies of plants and animals that live in a sea, river or lake will determine how healthy a species and its environment is. If one species of plant or animal is in serious decline, then a study would need to be made on how the creatures that normally feed on the plant or animal are surviving. It will be important to ascertain whether these species are also declining, or have adapted to the change by feeding on a different food source to survive.
Plants are necessary for butterflies to survive. In an area where a species of butterfly is in serious decline, if the plants that they depend on are in short supply, then the cause of the decline is easy to determine. If there is no shortage of the butterfly's food source, then other reasons will need to be found as to why the butterfly population is decreasing. There can be many reasons for the decline in a species, including climate change, intense predation, disease, etc. Careful observation will help to give a reason, or reasons, for the decline of the species.
Just slight changes in a habitat can be devastating to flora and fauna. Observing the health and numbers of all animal species will be helpful in the present. But it will also help to predict what creatures will suffer in the future -- if a particular species disappears. Conserving a habitat is the most important aspect of conservation. It means that instead of concentrating on saving one species of plant or animal, habitat conservation will help save several species at the same time. Habitat conservation means that an area should be studied on a regular basis, and, consequently, any decline in the population of a species will be recognized quickly.