Search results
Results from the WOW.Com Content Network
Sometimes, journeys are not termed "true migration" because they are irregular (nomadism, invasions, irruptions) or in only one direction (dispersal, movement of young away from natal area). Non-migratory birds are said to be resident or sedentary. Approximately 1,800 of the world's 10,000 bird species are long-distance migrants. [17] [18]
Some species such as Pacific salmon migrate to reproduce; every year, they swim upstream to mate and then return to the ocean. [7] Temperature is a driving factor of migration that is dependent on the time of year. Many species, especially birds, migrate to warmer locations during the winter to escape poor environmental conditions. [8]
Wildebeest migrating in the Serengeti. Migration, in ecology, is the large-scale movement of members of a species to a different environment.Migration is a natural behavior and component of the life cycle of many species of mobile organisms, not limited to animals, though animal migration is the best known type.
Bird flu 'ruffles feathers' of cattle in Texas, Kansas, and New Mexico. Migratory birds can have an outsized impact on the human world as well. In March, it was reported by the United States ...
While Parker birds for fun in Maine, for work he monitors two migratory bird species, the Eastern whippoorwill and the common nighthawk, one of the longest distance migratory birds in North America.
The migratory birds were also considered a delicacy, and the bird, known as the Waldrapp in German, disappeared from Europe, though a few colonies elsewhere survived.
Some species are migratory. The family contains 256 species which are divided into 12 subfamilies and 75 genera. Many well-known birds such as hawks, eagles, kites, harriers and Old World vultures are included in this group.
It's been shown that diet differs between non-migratory and migratory species in large-scale analyses and species-pair comparisons of frugivorous tropical birds. [ 15 ] While this hypothesis is supported, and has been the most accepted, it fails to explain why altitudinal migrants return to lower elevations, or if it is done in response to ...