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The drinking bird is a heat engine that exploits a temperature difference to convert heat energy to a pressure difference within the device, and performs mechanical work. Like all heat engines, the drinking bird works through a thermodynamic cycle. The initial state of the system is a bird with a wet head oriented vertically.
A freshwater aquatic food web. The blue arrows show a complete food chain (algae → daphnia → gizzard shad → largemouth bass → great blue heron). A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community.
Food chain in a Swedish lake. Osprey feed on northern pike, which in turn feed on perch which eat bleak which eat crustaceans.. A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as earthworms and woodlice ...
Human uses of birds have, for thousands of years, included both economic uses such as food, and symbolic uses such as art, music, and religion. In terms of economic uses, birds have been hunted for food since Palaeolithic times. They have been captured and bred as poultry to provide meat and eggs since at least the time of ancient Egypt.
The mean trophic level is calculated by assigning each fish or invertebrate species a number based on its trophic level.The trophic level is a measure of the position of an organism in a food web, starting at level 1 with primary producers, such as phytoplankton and seaweed, then moving through the primary consumers at level 2 that eat the primary producers to the secondary consumers at level ...
The pelagic food web, showing the central involvement of marine microorganisms in how the ocean imports nutrients from and then exports them back to the atmosphere and ocean floor. A marine food web is a food web of marine life. At the base of the ocean food web are single-celled algae and other plant-like organisms known as phytoplankton.
Providing birds with a safe and warm space is just as vital as extra food at this time of year. "Robins often use nest boxes as roosting sites during the winter, so putting up a suitable nest box ...
The term also includes waterfowls of the family Anatidae (ducks and geese) but does not include wild birds hunted for food known as game or quarry. Recent genomic studies involving the four extant junglefowl species reveals that the domestication of chicken, the most populous poultry species, occurred around 8,000 years ago in Southeast Asia ...