The Bilby, before European settlement where widely spread over around 70% of the Australian mainland than reduced to extinction in some states of Australia due to habitat loss and competition and predation from many introduced species. Through many reintroduction programs across Australia there population has now raised. The Greater Bilby is a nocturnal bandicoot, the largest of the family of marsupials. They have an excellent sense of smell and sharp hearing which they rely on as they have poor vision. Bilbies are omnivores, they eat things such as seeds, spiders, insects and their larvae, bulbs, fruit, fungi and small animals.
“Over 200 fish species have been introduced to the United States following importation, many of which threaten ecosystems and infrastructure” (103). When exotic animals are introduced to habitats they did not evolve with, they are without many of the environmental stressors that are placed on native animals, such as predation. When that characteristic is coupled with the fact that some exotic animals may be larger and more aggressive than its ecological counterpart, it becomes easy to see how non-native species out-compete native
Other invasive species may not destroy the habitat, but it can have an impact by killing large numbers of other species. Burmese pythons, for example, are top predators in the Everglades. As such, they have local mammal and bird populations. They are capable of consuming deer and even alligators, these creatures eat virtually any animal they encounter in the Everglades. A number of threatened and endangered bird species have also been found in the digestive tracts of pythons, prompting concern that they could drive some species toward extinction Lampreys in the Great Lake parasitize native fish.
The weight average of rainbow trout is about 3kg while individuals of rainbow trout can reach much heavier weights. Feeding habits: Rainbow trout are predators with varied diets depending on their life stages and availability of their natural diets. When they are young, rainbow trout will feed on small organisms such as zooplankton, and as they grow they feed on larval, pupal and adult forms of aquatic insects. They also eat fish eggs, small fish, crustaceans, mollusks, and insects. In vegetated habitats, rainbow trout often have the opportunity to eat terrestrial insects that fall into the water such as ants, beetles, and crickets.
Lionfish are damaging the communities that live in coral reefs. If lionfish overtake a coral reef, they can consume over one-hundred types of species of fish. Also, the fish that lionfish consume are necessary for habitat health because they regulate algae. Lionfish have been known to exist in various new areas including Gulf of Mexico, the Caribbean, and the Atlantic Ocean (Morris, J.A., Jr., and P.E. Whitfield).
Annual tolls because of sharks are much less than deaths resulted in meetings with crocodiles, tigers or elephants. Last two representatives of the huge terrestrial fauna kill around 100 people each year, while sharks have around five victims on their account. Meanwhile, tigers and elephants already had law protection, when the documentary was created, while sharks were treated as a source of valuable product (their fins) and a monster that should be killed before it would get an opportunity to attack. Numbers, mentioned by the film, created the impression the situation is totally unfair. As if officials today will forget about their efforts against the ivory black-market
If the abundance of the kelp forest changes it will also affect the amount of fish. Overfishing has led to an increase in sea urchins, which led to a deterioration of kelp forests. Other aspects that affect the kelp forest are diseases, harvesting for kelp, and pollution. When the top of the food chain is removed such as a starfish, barnacles and snails begin to rise. A lot of these animals are herbivores, which also eat kelp.
The cause for the bottleneck in the orca population was too old and widespread to be credited to human disturbance so it must have been caused by the last glacial maximum. The populations of orcas that recovered after the glacial period evolved to change. Some remained predators to fish and birds, others evolved to a different niche of marine mammals and sharks. These populations diverged due to geographic differentiation and this also could have affected the intraspecific evolution of these orcas. However even though the killer whales at different locations have similar genetic variation this variation is enough to separate them, partially because the kinship genetic variation within a specific population is even smaller.
The Negative Effects Captivity has on Orcas Orcas, also known as killer whales, have been captured and placed in captivity beginning in 1961. Not only were orcas captured and brought into captivity, many were born into captivity. An increasing amount of Orcas in captivity has started a serious conversation on whether Orcas are benefiting or suffering from being held in captivity. There are differing opinions about captivity having a positive or negative effect on the Orcas well-being. There are numerous amounts of negative effects resulting from orcas being captured and kept in captivity including: separation from pods, aggression towards other whales, aggression towards humans, a shortened lifespan, lack of exercise, tooth decay, lack of natural enrichment, unnatural reproduction, food deprivation, and the drugging of orcas.
As they usually hunt old, weak or sick prey, they help to keep the prey population in good condition, healthy and strong, enabling these more naturally fit animals to reproduce and pass on their genes. The effects of removing sharks from ocean ecosystems, although complex and rather unpredictable, are very likely to be ecologically and economically damaging. Here are some reason why killing sharks is very bad: 1)Sharks are being fished at a rate faster than they can recover. Due to overexploitation and lack of proper management, many shark species are under considerable risk of unrecoverable decline with some species having declined to near extinction in recent years. According to reports, sharks are being killed at an alarming rate of up to 273 million worldwide per year.
Natural Selection Introduction: Natural Selection is the ability to survive and reproduce in a given environment. It is known due to evolution that has occurred over time and how mutation, migration, and genetic drift have changed. There is a variation in traits in animals, for example some birds have bigger beaks that can be used to feed on worms and bugs that are way underneath the river and lakes. Also there is a differential reproduction that occurs because not all animals can reproduce the same amount and there is a limit that the environment can support over time. Some bugs due to their color can be an easy target for birds to eat and makes it harder for them to keep reproducing the same trait.