Communities and Ecosystems

Nature is a mosaic of complex interactions and relationships between animals, plants, and their environment. Individual organisms belong to populations, species, communities, and ecosystems. Energy flows from one organism to another and it is through these relationships that populations influence each other and the environment. Find out more about community and ecosystems.

Communities and Ecosystems

Nature is a mosaic of complex interactions and relationships between animals, plants, and their environment. Individual organisms belong to populations, species, communities, and ecosystems. Energy flows from one organism to another and it is through these relationships that populations influence each other and the environment. Find out more about community and ecosystems.

Falcons

Falcons are a group of birds of prey that includes 37 species. Falcons fall into several general groups including the kestrels, the hobbies and their relatives, the peregrine falcon and its relatives and the hierofalcons. The fossil record for falcons is not as complete as other birds of prey.

European Badgers

The European badger is a mammal native to Europe noted for the extensive tunnels it builds. These tunnels, also known as sets or dens, are as much as six feet deep and can measure some 1000 feet in length with many chambers and openings that create a complex underground network.

Bivalves

Bivalves (Bivalvia) are a group of molluscs that include clams, scallops, oysters, mussels, razor shells, cockles, venus shells, borers, trough shells and many others (some of which have yet to be identified). Bivalves are so named for their paired shells. The shells of a bivalve are made up of two halves that are mirror images of each other and are joined at one edge by a flexible hinge. Each half is asymmetrical and rounded, so that when closed against the other half, forms a domed space near the hinged edge of the shell which accommodates the bulk of the animal's body and narrows towards the edge of the shell that opens.

The Movement Patterns of Leatherback Turtles

Leatherback turtles in the Eastern Pacific Ocean spend more energy searching for prey than the leatherback turtles that inhabit the North Atlantic ocean. A team of scientists led by Helen Bailey of the University of Maryland Center for Environmental Science discovered that turtles in the Atlantic traveled at different speeds. When foraging, the Atlantic turtles traveled at low speeds but when in transit from one foraging ground to the next they travelled at higher speeds.

In contrast, leatherback turtles of the Eastern Pacific Ocean travelled at just one speed and spent most of their time searching for good foraging areas. This means that turtles that inhabit the Atlantic may be able to recover from population declines more easily than those that live in the Pacific.

Brittle Stars and Basket Stars Echinoderms with Inflexible Arms

Like sea stars, brittle stars and basket stars have (in most species) five arms (which in some species are highly branched). But the arms of brittle stars and basket stars differ from those of star fish in that their central disk is easily distinguished from their arms (in starfish, the arms blend with the central disk such that it is difficult to see exactly where the two meet).

Brittle stars are so named because their arms can only move side to side and not up and down. If their arm is forced either up or down, it breaks. The lateral arm movements used by brittle stars and basket stars enables them to crawl across the substrate or cling to surfaces. There are about 2000 species of brittle stars and basket stars and they exhibit a range of feeding methods from filter feeding to scavenging to predation.