Animal migration


Animal migration
Wildebeest Connochaetes taurinus crossing a river in East Africa.

Animal migration is the relatively long-distance movement of individuals, usually on a seasonal basis. It is a ubiquitous phenomenon, found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans.[1] The trigger for the migration may be local climate, local availability of food, the season of the year or for mating reasons.[2] To be counted as a true migration, and not just a local dispersal or irruption, the movement of the animals should be an annual or seasonal occurrence, such as birds migrating south for the winter, or a major habitat change as part of their life, such as young Atlantic salmon leaving the river of their birth when they have reached a few inches in size.[3]

Contents

Definition

Migration can take very different forms in different species and as such, there is no simple accepted definition of migration. One of the most commonly used definitions, proposed by Kennedy[4] is

“Migratory behavior is persistent and straightened out movement effected by the animal’s own locomotory exertions or by its active embarkation upon a vehicle. It depends on some temporary inhibition of station keeping responses but promotes their eventual disinhibition and recurrence.”

Migration has also been described as a term that describes the four related concepts [1]:

  1. persistent, straight, movement behavior
  2. relocation of an individual on a greater scale (both spatially and temporally) than its normal daily activities
  3. seasonal ‘to-and-fro’ movement of a population between two areas
  4. movement leading to the redistribution of individuals within a population

Migration Types

Migration can be either obligate, meaning individuals must always migrate, or facultative, meaning individuals can choose to migrate or not.

Within a migratory species or even within a single population, often not all individuals migrate. Complete migration is when all individuals migrate, partial migration is when some individuals migrate while others do not, and differential migration is when the difference between migratory and non-migratory individuals is based on age or sex (for example).[1]

While most migratory movements occur on an annual cycle, some daily movements are also referred to as migration. For example, many aquatic animals make a vertical migration (Diel vertical migration), travelling a few hundred metres up and down the water column.[5] Similarly, some jellyfish make daily horizontal migrations, traveling a few hundred metres across a lake.[6]

Multiple generation migration

A christmas island red crab on its migration.

In some insect species, such as the monarch butterfly, the whole migration is not carried out by one individual. Instead the butterflies mate and reproduce on the journey, and successive generations travel the next stage of the migration.

Human cultural responses to animal migration

Before the phenomenon of animal migration was understood, various folklore and erroneous explanations sprang up to account for the disappearance or sudden arrival of birds in an area. In Ancient Greece, Aristotle proposed that robins turned into redstarts when summer arrived.[7] The barnacle goose was explained in European Medieval bestiaries and manuscripts as either growing like fruit on trees, or developing from goose barnacles on pieces of driftwood.[8] Another example is the swallow, which at various times was suggested to hibernate either underwater, buried in muddy riverbanks, or in hollow trees.

Mexican free-tailed bats on their long journey of flight.

See also

References

  1. ^ a b c Hugh Dingle and V. Alistair Drake (2007). "What is migration?". BioScience 57: 113–121. doi:10.1641/B570206. http://www.bioone.org/doi/abs/10.1641/B570206. 
  2. ^ http://education.nationalgeographic.com/education/activity/why-animals-migrate/?ar_a=1&ar_r=999
  3. ^ David Attenborough (1990). The Trials of Life. London: Collins/BBCBooks. p. 123. ISBN 0002199408. 
  4. ^ Kennedy, J. S. (1985). "Migration: Behavioral and ecological.". In M., Rankin. Migration: Mechanisms and Adaptive Significance: Contributions in Marine Science. Marine Science Institute. pp. 5–26. 
  5. ^ I.A. McLaren (1974). "Demographic strategy of vertical migration by a marine copepod.". The American Naturalist 108 (959): 91–102. JSTOR 2459738. 
  6. ^ W.M. Hamner, I.R. Hauri (1981). "Long-distance horizontal migrations of zooplankton (Scyphomedusae: Mastigias).". Limnology and Oceanography 26 (3): 414–423. 
  7. ^ "The Earthlife Web - What is Bird Migration". http://www.earthlife.net/birds/migration1.html. 
  8. ^ "Medieval Bestiary - Barnacle Goose". http://bestiary.ca/beasts/beast1195.htm. 

Further reading

Migration, Generally

Taxon-specific Migration

  • Alerstam, T. (1990) Bird migration. Cambridge University Press.
  • Berthold, P. (2003) Avian migration. Springer Publishing.
  • Elphick, J. (1995) The atlas of bird migration: tracing the great journeys of the world's birds. Random House.
  • Greenberg, R. and Marra, P. P. (2005) Birds of Two Worlds: The Ecology and Evolution of Migration. Johns Hopkins University Press.
  • Drake, V. A. and Gatehouse, A. G. (1995) Insect migration: tracking resources through space and time. Cambridge University Press.
  • Harden Jones, F. R. (1968) Fish migration. St. Martin’s Press.
  • Lucas, M. C. and Baras, E. (2001) Migration of freshwater fishes. Blackwell Science.
  • McKeown, B. A. (1984) Fish migration. Timber Press.

External links


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Tracking animal migration — For years scientists have been tracking animals and the ways they migrate. Many have done this for research, some have done this to help animals and monitor them. Technologies for tracking In the fall of 1803, American Naturalist John James… …   Wikipedia

  • Migration — Migration, Migratory behavior, or Migratory may refer Gene migration, a process in evolution and population genetics Animal migration, the travelling of long distances in search of a new habitat Human migration, physical movement by humans from… …   Wikipedia

  • animal learning — ▪ zoology Introduction       the alternation of behaviour as a result of individual experience. When an organism can perceive and change its behaviour, it is said to learn.       That animals can learn seems to go without saying. The cat that… …   Universalium

  • Migration des insectes — Des monarques migrant par milliers vers le site d Angangueo dans le nord du Michoacán au Mexique. Des milliards d insectes migrent chaque année, certains sur de petites distances, d autres sur des distances intercontinentales, comparables à… …   Wikipédia en Français

  • Migration Des Oiseaux — La migration des oiseaux est un mouvement régulier observé chez de très nombreuses espèces d oiseaux. Ce déplacement est, par exemple, une manière pour ces espèces d échapper à un changement d habitat ou une baisse de disponibilité de nourriture… …   Wikipédia en Français

  • Migration aviaire — Migration des oiseaux La migration des oiseaux est un mouvement régulier observé chez de très nombreuses espèces d oiseaux. Ce déplacement est, par exemple, une manière pour ces espèces d échapper à un changement d habitat ou une baisse de… …   Wikipédia en Français

  • migration — [ migrasjɔ̃ ] n. f. • 1495; lat. migratio 1 ♦ Déplacement de populations qui passent d un pays dans un autre pour s y établir. ⇒ émigration, immigration. Migration provoquée par une guerre. ⇒aussi exode. Migration des barbares. ⇒ invasion. ♢… …   Encyclopédie Universelle

  • ANIMAL (RÈGNE) - Évolution animale — La notion d’histoire du règne animal est relativement récente dans la pensée scientifique. Après la Renaissance, les premiers naturalistes cherchaient seulement à mettre de l’ordre dans nos connaissances en comparant les caractères des divers… …   Encyclopédie Universelle

  • Migration Animale — Chez les animaux, la migration est un phénomène présent chez de nombreuses espèces, qui effectuent un déplacement (voire un périple), souvent sur de longues distances, à caractère périodique qui implique un retour régulier dans la région de… …   Wikipédia en Français

  • Animal style — (also known as Zoomorphic style) is a type of imagery used in Northern Europe during the ancient and medieval periods, characterized by animals or animal like forms arranged in intricate patterns or combats. Animal Style Art consists of intricate …   Wikipedia