The Anguilla Bank skink "(Spondylurus powelli)" was discovered in the Caribbean with 20 other reptile species and was immediately listed as an endangered species.
 The population of this lizard has been decreasing due to the introduction of the mongoose originally to control rats in sugarcane fields, and now is an invasive species to the Caribbean Islands.
 Many of the newly added skink species discovered along with "S. powelli" are facing extinction for the same reason.
 Skinks are unique and perhaps at a disadvantage among lizards as they produce a human-like placenta and have live birth.
 The average gestation period is suggested at one year and may be the cause for the skinks being an easy target to the mongoose, since they are larger and slower when pregnant.
 Other types of human activity, along with the deforestation in the Caribbean, are thought to have decreased overall species numbers, as well.
David Boynton (1945–2007) was a leading expert on the natural history of the Hawaiian island of Kauai, especially on the Koke'e Forest and the Alakai Swamp and its wildlife.
 He was called "a voice for the Hawaiian wilderness," a "Guardian of the Koke'e Forest," and as an educator, "the window through which thousands of Hawai'i students learned about Hawaiian birds, plants, marine creatures, climate and much more."
 Boynton photographed a bird now believed extinct, the ʻ Ōʻ ōʻ āʻ ā ("Moho braccatus").
 He recorded the mating call of the single male, whose mate presumably did not survive Hurricane Iwa at the end of 1982.
 The bird, probably the last of its species, was tending an empty nest.
An ecological cascade effect is a series of secondary extinctions that is triggered by the primary extinction of a key species in an ecosystem.
 Secondary extinctions are likely to occur when the threatened species are: dependent on a few specific food sources, mutualistic (dependent on the key species in some way), or forced to coexist with an invasive species that is introduced to the ecosystem.
 Species introductions to a foreign ecosystem can often devastate entire communities, and even entire ecosystems.
 These exotic species monopolize the ecosystem's resources, and since they have no natural predators to decrease their growth, they are able to increase indefinitely.
 Olsen et al. showed that exotic species have caused lake and estuary ecosystems to go through cascade effects due to loss of algae, crayfish, mollusks, fish, amphibians, and birds.
 However, the principal cause of cascade effects is the loss of top predators as the key species.
 As a result of this loss, a dramatic increase (ecological release) of prey species occurs.
 The prey is then able to overexploit its own food resources, until the population numbers decrease in abundance, which can lead to extinction.
 When the prey's food resources disappear, they starve and may go extinct as well.
 If the prey species is herbivorous, then their initial release and exploitation of the plants may result in a loss of plant biodiversity in the area.
 If other organisms in the ecosystem also depend upon these plants as food resources, then these species may go extinct as well.
 An example of the cascade effect caused by the loss of a top predator is apparent in tropical forests.
 When hunters cause local extinctions of top predators, the predators' prey's population numbers increase, causing an overexploitation of a food resource and a cascade effect of species loss.
 Recent studies have been performed on approaches to mitigate extinction cascades in food-web networks.
The Kauaʻ i ʻ ōʻ ō or ʻ ōʻ ōʻ āʻ ā (Moho braccatus) is a member of the extinct genus of the ʻ ōʻ ōs ("Moho") within the extinct family Mohoidae from the islands of Hawai'i.
 It was previously regarded as member of the Australo-Pacific honeyeaters ("Meliphagidae").
 This bird was endemic to the island of Kauaʻ i.
 It was common in the subtropical forests of the island until the early twentieth century, when its decline began.
 Its song was last heard in 1987 and it is now probably extinct.
 The causes of its extinction include the introduction of the Polynesian rat, domestic pig, and mosquitoes carrying avian disease (avian malaria and avian pox), as well as habitat destruction.
The Polynesian rat, or Pacific rat ("Rattus exulans"), known to the Māori as kiore, is the third most widespread species of rat in the world behind the brown rat and black rat.
 The Polynesian rat originated in Southeast Asia, and like its relatives, has become widespread, migrating to most Polynesian islands, including New Zealand, Easter Island, and Hawaii.
 It shares high adaptability with other rat species extending to many environments, from grasslands to forests.
 It is also closely associated with humans, who provide easy access to food.
 It has become a major pest in most areas of its distribution.
Fibricola lucida is a fluke that infects Virginia opossums ("Didelphis virginiana"), American minks ("Neovison vison"), and marsh rice rats ("Oryzomys palustris") in North America.
 In a study in Florida, "F. lucida" was the only fluke of the marsh rice rat (among 21 species recorded) that occurred in both the freshwater marsh at Paynes Prairie and the saltwater marsh at Cedar Key.
 At the former locality, it infected 11% of rice rats and the number of worms per infected rat ranged from 1 to 65, averaging 17.
 At Cedar Key, 67% of rice rats were infected and the number of worms per infected rat ranged from 1 to 1975, averaging 143.
Megalomys desmarestii, also known as the Martinique muskrat, Desmarest's pilorie, or the Martinique giant rice rat, is an extinct rice rat from Martinique in the Caribbean.
 It was among the largest species of West Indian rice rat, as big as a cat, and was one of the first Caribbean mammals to become extinct during the 20th century.
 It may have been aquatic, as it was known to escape into the sea when pursued by predators, but it never swam away from the island.
 It was common on Martinique until the end of the nineteenth century, when attempts were made to exterminate it because it was considered to be a pest in the island's coconut plantations.
 It was also hunted for food; however due to a strong musky odor cooking required people to singe off its hair, air out the body overnight and boil it in two batches of water.
 On 8 May 1902, the volcano Mount Pelée erupted, completely destroying the island's principal city of Saint-Pierre.
 It has been speculated that the rice rat became extinct then or during a later eruption in 1902, but predation by introduced mongooses is more likely to have been the primary cause of its extinction.
Maclear's rat ("Rattus macleari") was a large rat which lived on Christmas Island in the Indian Ocean.
 Abundant, unfamiliar with and seemingly unafraid of humans, large numbers of the creatures emerged and foraged in all directions at night.
 Making querulous squeaks, the rats entered the "Challenger" Expedition's tents and shelters, ran over sleepers, and upset everything in the search and fight for food.
 Maclear's rat may have been responsible for keeping the population of the Christmas Island red crab in check, as recent numbers of the crab are greater than in the past.
 It is thought that black rats inadvertently introduced by the expedition infected the Maclear's rats with a disease (possibly a trypanosome), which in turn may have contributed to the species decline.
 The last recorded sighting was in 1903, although it is possible that Maclear's rats formed hybrids with black rats.
 A hard tick, "Ixodes nitens", described as an ectoparasite of Maclear's rat is also thought to be extinct.
An earthdog trial tests the working ability and instinct of the small, often short-legged terriers or Dachshunds.
 These dogs were bred to hunt vermin and other quarry which lived in underground dens.
 Earthdog den trials involve man-made underground tunnels that the dogs must navigate, while scenting a rat, "the quarry."
 The dog must follow the scent to the quarry and then "work" the quarry.
 Depending on the sanctioning organization, “working” means barking, scratching, staring, pawing, digging; any active behavior.
 The quarry is protected at all times by wooden bars across the end of the tunnel.
 The hunting encounter is controlled, and neither the dog nor the quarry (usually two rats) are endangered by the activity.
The cloud rats are a group of arboreal and folivorous nocturnal rodents native to the forests of the Philippines.
 There are six known species of true cloud rat, and two dwarf cloud rat species.
 These animals have not been studied extensively.
 The Filipino Ecosystems Research and Development Bureau has begun breeding Northern Luzon slender-tailed cloud rats in captivity.
 Several European and North American zoos keep a breed cloud rats in captivity, such as London Zoo, Prague Zoo, Central Park Zoo and the Bronx Zoo.
 Some species of cloud rats are kept in the mini-zoo of the College of Agriculture and Forestry of the West Visayas State University in their Lambunao campus in the province of Iloilo.
 Cloud rats are slow-moving herbivores and are thought to be preyed upon by large birds such as the Philippine eagle.
 The rats are quite large, and they have been hunted by people in the Philippines for their meat, driving the rodents to near extinction.

Question: The cause of the Moho braccatus extinction include the introduction of the third most widespread species of rat in the world behind what other two rats?
Answer: brown rat and black rat