Animal migration involves regular movement between locations. It is found in many animal groups and is usually seasonal. Migration ensures access to adequate food supplies and allows animals to reproduce. Prerequisites for migration include sustained movement, energy storage, and designated food sources along migration routes. Animals use both internal cues like hormones and external cues like temperature, daylight hours, and food scarcity to determine when and where to migrate. Migration allows animals to access resources in different habitats and environments.

1. Migration is the regular movement of animals from one
location to another.
What is migration?
•Animal migration is the relatively long-distance
movement of individuals, usually on a seasonal basis.
•It is found in all major animal groups.
•It can be also defined as :-
•A movement leading to the redistribution of
individuals within a population.
MIGRATION OF ANIMALS

2. Prerequisites for migration:
1. Sustained movement
2. Physical stamina
3. Mechanisms for storing energy
4. Designated food sources on the migration route
Migration ensures animals will have adequate food supplies & will be
able to reproduce.
The study of periodic phenomena (such as migration) in animals in relation
to changes ,climatic and other ecological factors are called phenology

3. Evolutionary model of migration (baker 1978)
•Animal tend to assess the utility of their present habitat (h1) relative to that of another potential habitat (h2).
•They migrate only when the utility of h1 drops below that of h2 multiplied by a migration factor (m)
(ie., h1 is less than that of h2m)
migration
Species
migration
Individual
migration
accidental Non-accidental
Non-calculated calculated
dispersal exploratory removal periodic seasonal

4.  Migration may occur:
As a voyage with no return
As a return migration
Corresponds with the seasons
 Some require a lifetime to complete:
Ex: Pacific salmon
Born in freshwater streams
Travel to the ocean
Return to the stream where they were born
•Spawn and then die
Types of Migration

5.  How do animals know when it is time to
migrate?
Internal signals
Hormones trigger an overwhelming urge
to…
•eat, mate & reproduce
External signals (clues)
Temperature change
Daylight hours
Scarce food supply
Knowing When to Migrate

6.  How do animals know where to go?
 Specialized abilities to navigate
 External forces
 Ex.: wind & water currents
 Landmarks:
 Ex.: coastlines, mountain ranges, river valleys & distinctive odors
 Sun:
 Track the passage of days and months
 Track their position in relationship to the sun
Migration Destinations

7.  Internal Clues
 Are sensitive to a mineral known as magnetite
 Found in many animals,
Allows animals to use the earth’s magnetic field as a guide.
 Ex.: Gray whales
 Large amount of magnetite in their retinas
• Helps them navigate their 10,000 mile journey
Migration: Behavior or Instinct?
Migration is instinctive
Fly without guidance or previous experience
Use little or no directional clues
Learning migration behaviors for most animals is critical to their survival.

8.  Older members of the group teach
the younger animals:
The route traveled
Valuable strategies and/or behaviors
 Most animals must learn their migratory routes.
Animals who are not taught these behaviors
will not likely survive.
Migration Behaviors
1. Shortage of food supply on the breeding ground
2. Environmental factors
3. Internal factors
4. Photoperiodism
5. Fat deposition

9. Pattern of migration?
 3 types
1. Diurnal and tidal movements
2. Seasonal movements between habitats
3. long distance migration
1.DIURNAL AND TIDAL MOVEMENTS
 Many species move from one habitat to another and back again repeatedly during
their life
 time scale involved may be hours ,days, month or years
 Eg : crabs on shoreline (tidal movement)
 Diurnal migration involve moving between two habitats,each of which can supply
limited resources
 Eg : planktonic algae both in sea and fresh water lakes move depth @ night but move
to surface during day.

10. 2.SEASONAL MOVEMENT BETWEEN HABITAT
 Seasonal movement between habitat
 The path of environment in which the resources are available change with seasons and
population move one patch to another
 eg : altitudinal migration of mule deer and american elk (move to high mountain during
summer &down to valleys in winter)
3.LONG DISTANCE MIGRATION
 Travells long distance
 Eg: terrestrial bird in northern hemisphere move north in the spring when the food
supplies will become abundant during summer period
 Move to south savannahs in the autumn when food become abundant only after the
rainy season
 so long distant migration seems to involve transit between area that have supply of
abudant food but only for a limited period
 Eg: swallows

11. Which animals migrate?
1. birds
2. fishes
3. mammals
4. reptiles
5. amhibians
6. invertebrates
o It is the seasonal movement from one habitat to another and back again ,to get the advantages of favorable
conditions
o Usually , birds migrate to northern hemisphere in spring to breed and return to southern hemisphere in autumn to
pass the winter

12.  Over 5 billion land birds of 187 species migrate between Europe and
Asia to Africa
 Over 5 billion land birds of over 200 species migrate between North
America and the New World tropics
 75% of 650 bird species that nest in N. America migrate

13. Migrating bird is called migrant
1.Winter visitors ( N S)
 Include those species move from their breeding ground to spent
their winter in a suitable place ,food is also plenty
 Field fare, snow bunting, red wing
 grey lag goose, pintail, common teal, gadwal, european starling
are the winters visitors (migrants) visiting keoladeo national
park,bharatpur
Field fare
Snow bunting

14. 2. Summer visitors(S N)
 Spring onwards ,south start getting hot
 the birds of south leave it in spring for north to spend the
summer ,breed & return to south in autumn ,
 eg: swifts swallows,nightingales,cuckoo
swift
3.Transient visitors or passage migrants
 These are summer and winter visitors while migrating from
south to north and vice versa
 Stop at some places for the sake of rest only
 Eg: gargany teals migrate from mangolia or siberia to bharatpur
to go south india which is their actual breeding ground,while
returning that again stop over @ bharat pur Gargany teals

15. 4.Permanent resident
 these birds found in a particular area through out the year and
do not migrate from one place to another
Eg: cotton teal, spotbill duck, whistling teal, barheaded goose,
mallard, comb duck
 these birds are permanent residents of keoladeo national park
,bhartpur
mallard

16. 1.Daily migration
Many birds make daily movements from their nest in response to environmental forces
such as light,darkness temperature,humidity etc.
Daily migration from their resting site to feeding area.
Eg: crows , sparrows, starling
2.Local migration
Local migration occurs because of heavy rain, flood, excessive cold & hot
Return to that area when crisis is over
Flowering of certain plants and ripening of fruits also cause local
migration

17. 3.Seasonal migration
 Response to change in the season
 tropical & sub tropical countries area, this occurs in the beggining of the warm season
Temperate area ,the movement is triggered by onset of winters.
4.Moult migration
 Most ducks, males and juveniles birds migrate short distances northward
for moulting leaving behind the females and young birds in breeding ground

18. 5.Cyclic migration
 Migration of birds are seasonal, but do not occur at regular intervals.
 Eg: snowy owl in search of lemming in U.S in winter is occurs in 3 – 5 years
6.Partial migration
 All the birds of migratory bird do not leave the native land and hence
are always represented by certain individuals
Eg: finch, titmouse
7.Irregular migration
 Sometimes some birds disperse for a short or long distance for the sake of food and
safety
The birds can also swept away by powerful wind and hurricanes to very long distance

19. 8.Altitudinal or vertical migration
The birds living @ high altitude descends @ lower
altitude in winter to save them selves from intense cold
of high altitude
They return again to high altitude with advent of
summer
Eg: blue grouse
9.Latitudinal or equatorial migration
 The most familiar migration are those from north to south
and vice versa
Eg; california gull,golden plover
10.Longitudinal migration
 east to west.
Eg: gross beaks,starling

20. Based on wing power and method of getting food william brewster divided birds in to three categories
1.Night filters
 usually small birds
 night filters are usually prefer darkness provides them protection from large predatory birds
It also gives birds opportunity of using all the day light hours for feeding ,enabling them to build up
sufficient energy resources for sustaining long distance flights
Eg:sparrows, titmice, wood peckers
2.Day filters
 birds prefer day light
Eg: hawks, pigeons, swalllows and robbins
3.Few birds such as geese and ducks ,migrate both by night and day

21. Emperor Penguin follows a long migration path to Antarctica away from their home
by the edge of the sea.
They do so because during the fall Emperor Penguins mate and the female lays an
egg.
They migrate inland away from water as the egg hatches.
So that there is more ice under the newborn penguin's feet and much less chance of it
falling through into the ocean.
Emperor Penguin : The largest migratory penguin species

22. The distance travelled by migratory bird depends on the local conditions.
The longest distance of about 17600kms is covered by arctic tern
Makes the longest migration ever recorded on earth.
Flies from its Arctic breeding grounds to the Antarctic and back again each year.
The annual round trip of this small seabird is approximately 71000 kilometers.
Thus in its whole lifetime, it makes a journey equivalent to 3 return journeys to the Moon!
Bird of the Sun : Arctic Tern

23. It thought that the birds are travelled very high & very fast speed
 Recent knowledge obtained by
Telescope
Radar
Radiotelemetry
 pointed out that some birds fly @ sea level
 Some fly very close to the height of mount everest,
most birds fly less than 7400 feet above sea level

24. Flying speed is measured by doppler radar
Speed ranged from 32-64 kmph in small song birds
Larger birds ,such as cranes 40-96 kmph
Perching birds can fly 32-59 kmph
Falcons, ducks, geese fly @ speed of 77-96kmph
Humming bird fly 32 kmph

25. Makes the longest migration among the cranes.
Travels nearly half of the globe to the Keoladeo National park in India to
spend the winter months.
Their migration route stretches for 4000 miles.
Siberian Cranes

26. 1. Securing a better climate for living by avoiding unfavorable climatic condition
(intense cold, hot, stromy conditions ) & food shortage by migrating
2. By alternately exploiting 2 different habitat for food due to migration ,more birds can
able to exist
3. Change in habitat provides greater variety in bird diet
4. Long summer days provide birds with long working hours to gather food to feed
young ones

27. 5. Predation pressure is less because it arrives in large numbers in breeding ground ,so it help in their
survival
6. Migration provide certain evolutionary benefits
7. Migration promotes the geographical dispersal of birds (isolating mechanism)
 Two categories:
 Natural hazards:
• Climate changes
• Drought
• Food Supply
• Predators
• Physical demands of migration
• Journey is tiresome
Hazards of Migration
 Man-made hazards:
• Barriers (fences, dams, & skyscrapers)
• Water, aircraft, & fishing practices
• Telegraphic wires,towers,light houses

28. 1. Movement of fishes from one habitat to another for the purpose of feeding, spawning
or shelter is called fish migration
2. Many type of fish migrate on a regular basis ,on time scale ranging from daily to annually
or longer
3. They travel over distances ranging from
Few meters to thousands of kilometers
1. Daily : mainly for food gathering
2. Annual :mainly for reproduction
3. Generational : parent migrate to release egg & die.Then there young
once migrate to the home

29. According to cohen(1970),about 8000 fresh water,12000 marine spps
are migratory.
Approx. 70% found in warm waters
Examples are; Hilsa, Salmon, Eel, Tuna, Herring, Mackerel, Sword fish,
Cod Fish, Plaice, Barracudas.

30. On the basis of cause, fish migration is of following types
Feeding or alimental migration:- It takes place in fishes for feeding.
Examples:- Salmons, cods and sword fish migrate for food.
Spawning migration :- It takes place in breeding season in those fishes which
have spawning grounds far away from the feeding places.
Examples:- Eels, salmons and a large no. of riverine fishes.
Juvenile migration:- It involves larval stages of fishes which hatch in spawning
grounds and migrate long distances to reach the feeding habits of their parents.
Recruitment migration:- It takes place when large no. of larvae move from
nursery habitat to the habitat of adults.
Seasonal migration:- It takes place in fishes that inhabit arctic areas where in
summer climate is conducive and food abundant but as winter approaches
temperature fall below zero and food becomes scarce. Hence, fishes must
migrate towards subtropical and tropical areas to escape extremes of weather
conditions.

31. Different types of fish migration on the basis of
habitat
Potamodromous Migration:-When fishes migrate from one freshwater
habitat to another in search of food or spawning, it is called as
potamodromous migration.
Fishes also migrate to lay eggs in places where oxygen concentration in
water is more and where there is abundance of food for juveniles when
they hatch from eggs.
Example:- Common Asian Carps

32. Cont….
Oceanodromous Migration:- This migration is from sea water to sea
water.
Example:-There are about 12,000 marine species that regularly migrate
within sea like herrings, sardines, mackerels, cods, roaches and tunas.
Diadromous migration:- When fishes can migrate from fresh water to sea
water or from sea water to fresh water, it is called diadromous migration.
It involves 120 species of fishes that are capable of overcoming osmotic
barriers and migrate in these habitats.

33. Types of diadromous migration
• 1.Catadromous Migration
• 2.Anadromous Migration
• 3. Amphidromous migration

34. Catadromous Migration
• This type of migration involves movement of large number of fishes from
fresh water to sea water, generally for spawning
• as happens in the case of Anguilla(eels).

35. Anadromous Migration
It involves migration of fishes from sea water to fresh water.
Example:- Salmon and trout

36. Amphidromous migration
• Migration from sea to river and vice versa but not for reproduction, but
for food or for change of enviroment.
• Occur only in Gobies

37. Among the mammals wildebeest, caribou, zebra, gazelle, bison, seals
perform arduous journeys each year
Different species move round is determined by specific food requirement
The most morality factor in the migrant zebra, wilde beest, and gazelle
population is predation
Some migrant animals may die of starvation

38. •The blue wildebeest migrates annually from Kenya to northern South Africa.
•About 250000 wildebeests die each year when they cross the Grumeti River.
•They become the chief source of food for Nile crocodiles.
•The crocodiles feed, when blue wildebeests arrive during their annual migration.
Migrating Wildebeest

39. • The animals may move in smaller groups (not more than 50)
on the mainland of Canada.
• They travel 1,200 km (746 mi) in a season.
Caribou : The Reindeer

40. Massive Migration
The Mali Elephant takes on the longest elephant migration on earth.

41. Migratory reptiles include leather back
turtle
Green sea turtle(chelonia)

42. 1.Living in continental shelf of united states.
2.They apparently move back and forth from deep water to coastal areas.
3.It is a one way trip frequently exceeding 80 km.
Monarch butterfly : Born To Move

43. Known for its extraordinary long migrations.
The longest recorded flight for a tagged adult is 2,900 km
Their annual migration takes four generations to complete.
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