In an ecology sense, a pandemic species is one that is widely distributed throughout a country or continent. Its opposite is endemic, meaning species only found in a particular region.
Most environments do not have sufficient resources to support unlimited populations of all the species present. Different species that have the same requirements for habitats and food will attempt to...
Yes, there is one that i know of. The Cuckoo bird lays its eggs in the nest of a host bird of another species, usually one with similar looking eggs to its own. The host bird then looks after the egg...