Tree squirrel Tree squirrel Tree squirrels are the members of the squirrel family (Sciuridae) commonly just referred to as "squirrels". They include over a hundred arboreal species native to all continents except Antarctica and Oceania. They do not form a single natural, or monophyletic group; they are related to others in the squirrel family, including ground squirrels, flying squirrels, marmots, and chipmunks. The defining characteristic used to determine which species of Sciuridae are tree squirrels is dependent on their habitat rather than their physiology. Tree squirrels live mostly among trees, as opposed to those that live in burrows in the ground or
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