BeetleBeetles are insects that form the order Coleoptera (koʊliː'Qpt@r@), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species.
BearBears are carnivoran mammals of the family Ursidae (ˈɜɹsɪdiː,_-d aɪ). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, and Eurasia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails.
OtterOtters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes weasels, badgers, mink, and wolverines, among other animals. The word otter derives from the Old English word otor or oter. This, and cognate words in other Indo-European languages, ultimately stem from the Proto-Indo-European language root , which also gave rise to the English word "water".
River ecosystemRiver ecosystems are flowing waters that drain the landscape, and include the biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts. River ecosystems are part of larger watershed networks or catchments, where smaller headwater streams drain into mid-size streams, which progressively drain into larger river networks. The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current.
Pioneer speciesPioneer species are hardy species that are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by wildfire. Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants. Since some uninhabited land may have thin, poor quality soils with few nutrients, pioneer species are often hardy plants with adaptations such as long roots, root nodes containing nitrogen-fixing bacteria, and leaves that employ transpiration.
Niche differentiationIn ecology, niche differentiation (also known as niche segregation, niche separation and niche partitioning) refers to the process by which competing species use the environment differently in a way that helps them to coexist. The competitive exclusion principle states that if two species with identical niches (ecological roles) compete, then one will inevitably drive the other to extinction. This rule also states that two species cannot occupy the same exact niche in a habitat and coexist together, at least in a stable manner.
Lake ecosystemA lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems (lentic refers to stationary or relatively still freshwater, from the Latin lentus, which means "sluggish"), which include ponds, lakes and wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams.
Haida peopleHaida (pron'haɪdə, X̱aayda, X̱aadas, X̱aad, X̱aat) are an indigenous group who have traditionally occupied Haida Gwaii, an archipelago just off the coast of British Columbia, Canada, for at least 12,500 years. The Haida are known for their craftsmanship, trading skills, and seamanship. They are known to have frequently carried out raids and to have practised slavery. The Haida have been compared to the Vikings of Scandinavia by Diamond Jenness, an early anthropologist at the Canadian Museum of Civilization.
NutriaThe nutria (Myocastor coypus), also known as the coypu, is a large, herbivorous, semiaquatic rodent. Classified for a long time as the only member of the family Myocastoridae, Myocastor is now included within Echimyidae, the family of the spiny rats. The nutria lives in burrows alongside stretches of water and feeds on river plant stems. Originally native to subtropical and temperate South America, it has since been introduced to North America, Europe, Asia, and Africa, primarily by fur farmers.
Virginia opossumThe Virginia opossum (Didelphis virginiana), also known as the North American opossum, is the only opossum living north of Mexico, its range extending south into Central America. It is the northernmost marsupial in the world. In the United States and Canada, it is typically called a possum, 'possum, or opossum. It is a solitary nocturnal animal about the size of a domestic cat, and a successful opportunist. Opossums are familiar to many North Americans as they frequently inhabit settled areas near food sources like trash cans, pet food, compost piles, gardens or housemice.
