Rodent on every continent except Antarctica. They are the only terrestrial placental mammals to have colonized Australia and New Guinea without human intervention. Humans have also allowed the animals to spread to many remote oceanic islands (e.g., the Polynesian rat). Rodents have adapted to almost every terrestrial habitat, from cold tundra (where they can live under snow) to hot deserts. Some species such as tree squirrels and New World porcupines are arboreal, while some, such as gophers, tuco-tucos, and mole rats, live almost completely underground, where they build complex burrow systems. Others dwell on the surface of the ground, but may
Introduced trout in lake ecosystems suitable food resources, are all factors that interact with fish introductions to influence impacts. Amphibian declines have become a worldwide issue that is most commonly attributed to chemical pollution, acid rain, ozone depletion, habitat destruction, as well as introductions of exotic species Recent studies have shown correlations of decline among amphibians to a chytrid fungus, which causes chytridiomycosis. The pathogen is one of many emerging infectious diseases that largely threaten amphibian populations, especially salamanders. Primarily spread through the import/export of live animals the threat lies when infected animals escape or are released into the wild. Copepods are diaptomids, or crustaceous