, are unique among lizards in that they produce a human-like placenta, which is an organ that directly connects the growing offspring to the maternal tissues that provide nutrients. "While there are other lizards that give live birth, only a fraction of the lizards known as skinks make a placenta and gestate offspring for up to one year," Hedges said. He also speculated that the lengthy gestational period may have given predators a competitive edge over skinks, since pregnant females are slower and more vulnerable. "The mongoose is the predator we believe is responsible for many of the species' close-to-extinction status in the Caribbean," Hedges said. "Our data show that the mongoose, which was introduced from India in 1872 and spread around the islands over the next three decades, has nearly exterminated this entire reptile fauna, which had gone largely unnoticed by scientists and conservationists until now."
According to Hedges, the "smoking gun" is a graph included in the scientific paper showing a sharp decline in skink populations that occurred soon after the introduction of the mongoose. Hedges explained that the mongoose originally was brought to the New World to control rats, which had become pests in the sugarcane fields in Cuba, Hispaniola, Puerto Rico, Jamaica, and the Lesser Antilles. While this strategy did help to control infestations of some pests; for example, the Norway rat, it also had the unintended consequence of reducing almost all skink populations. "By 1900, less than 50 percent of those mongoose islands still had their skinks, and the loss has continued to this day," Hedges said.
This newly discovered skink fauna will increase dramatically the number of reptiles categorized as "critically endangered" by the International Union for Conservation of Nature in their "Red List of Threatened Species," which is recognized as the most comprehensive database evaluating the endangerment status of various plant and animal species. "AcPage: 1 2 3 4 Related biology news :1
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