MIGRATION OF ANIMALS

BY,

SASNA.P.S

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.

Prerequisites for migration:

1.Sustained movement

2.Physical endurance

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

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

accidential

Non-accidential

Non-calculated

calculated

dispersal exploratory

removal periodic

seasonal

Migration may occur: As a round trip As a return migration

Corresponds with the seasons

Some require a lifetime to complete:

Ex: Pacific salmon Born in freshwater streamsTravel to the ocean Return to the stream where they were born

• Spawn and then die

Types of Migration

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

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

Internal Clues Are sensitive to a mineral known as magnetite Found in many animals, including humans

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.

Older members of the group teach the younger animals:

The route traveled Valuable strategies

and/or behaviorsHumans teach younger animals, too.

Ultra-light aircraft Taught various species of cranes their migration routes

Most animals must learn their migratory routes.

Animals who are not taught these behaviors will not likely survive.

Migration Behaviors

Causes of migration

1. Shortage of food supply on the breeding ground2. Environmental factors3. Internal factors4. Photoperiodism5. Fat deposition

Pattern of migration? 3 types1. Diurnal and tidal movements2. Seasonal movements between habitats3. 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 to 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.

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

Which animals migrate?

1. birds2. fishes3. mammals4. reptiles5. amhibians6. invertebrates

BIRD MIGRATIONo It is the seasonal movement from one habitat to another and back again ,to get the advantages of favorable conditions

o Traditional, hereditary ( instinctive), regular occurrence at definite intervals every year

o Usually , birds migrate from northern hemisphere in spring to breed and return to southern hemisphere in autumn to pass the winter

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

Migratory statusMigrating 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

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 thet again stop over @ bharat pur

Gargany teals

4.Permanent resident

these birds found in a particular area through out the year and do not migratefrom 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

Types Of Migration1.Daily migrationMany 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 &hotReturn to that area when crisis is overFlowering of certain plants and ripening of fruits also cause local migration

3.Seasonal migration Response to change in the season

tropical & sub tropical countries area, this occurs in the beggining or end 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

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 individualsEg: finch,titmouse7.Irregular migration Sometimes some birds disperse for a short or long distance for the sake of food and safetyThe birds can also swept away by powerful wind and hurricanes to very long distance

8.Altitudinal or vertical migrationThe birds living @ high altitude descends @ lower altitude in winter to save them selves from intense cold of high altitudeThey return again to high altitude with advent of summerEg: blue grouse

9.Latitudinal or equatorial migration The most familiar migration are those from north to south and vice versaEg; california gull,golden plover

10.Longitudinal migration east to west.Eg: gross beaks,starling

DIURNAL AND NOCTURNAL MIGRATION

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 birdsIt 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 flightsEg: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

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

RANGE OF MIGRATIONThe distance travelled by migratory bird depends on the local conditions.

The longest distance of about 17600kms is covered by artic tern (north to edge of antartica).

Golder plover migrate from artic tundra to the pampus of argentina.

The pectoral sand piper migrates from artic tundra to south america

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

Altitude of migrationIt 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

Flying speed during migration

Flying speed is measured by doppler radarSpeed ranged from 32-64 kmph in small song birdsLarger birds ,such as cranes 40-96 kmphPerching birds can fly 32-59 kmphFalcons, ducks, geese fly @ speed of 77-96kmphHumming bird fly 32 kmph

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

Advantages of migration

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 diifferent 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

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 so succum@sea

Man-made hazards:• Barriers (fences, dams, & skyscrapers) • Water, aircraft, & fishing practices• Telegraphic wires,towers,light houses

Hazards of Migration

Fish migration1. 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

Migration :based on duration

1. Daily : mainly for food gathering2. Annual :mainly for reproduction3. Generational : parent migrate to

release egg & die.Then there young once migrate to the home

SHOALING & SCHOOLINGWhen a large number of fishes come together and move socially it is called shoaling

Sometimes migrating fishes exhibit high degree of coordination in their movements and carry out synchronized manoeuvres to produce different type of shapes is called schooling , as seen in tunas and sardines

Types of migration

Diadromous fishes

Potamodromous fishes

Oceanodromous fishes

1.Anadromous fishes

• 2.Catadromous fishes

3.Amphidromous fishes• 4. semi-migratory

fishes

A.DIADROMOUS FISHESMigrate between fresh water & sea water

1.ANADROMOUS FISHES•These fishes migrate from sea to fresh water for spawning•Eg: pacific salmon ,sturgeon

2.CATADROMOUS FISHES•These fishes migrate from fresh water to sea for spawning•Eg : anguila

3.AMPHIDROMOUS FISHES•Migrate from fresh water to sea water vice versa•It occur some definite stage of life cycle•Eg :gobis

4.SEMI MIGRATORY FISHES• migrate from sea water to estuaries and are not marked by migratory changes• eg : roaches,white fish, milk fish

•b.Potamodromous fishes•These fishes live & migrate only in fresh waters•Eg: carp,trout

c.Oceanodromous fishes•the fishes only migrate with in the sea•Eg : herring, sardine,mackeral

BASED ON PURPOSE(MIGRATION)

alimental

Gametic /Spawning

/breeding

Climatic or

wintering

Osmoregulatory /

protective

Search of food Eg:chanos

Proper survival & development of eggs & larvaeEg: hilsa

Secure more suitable climatic cinditionEg: atlantic salmons

Maintaining osmoregulation

During the monsoon and consequent flooding of all the rivers, Hilsa shad starts its spawning migration upstream.

Hilsha migrates at least 1,200 km up in some river system in Indian sub-continent. Distances of 50-100 km are more typical in Bangladesh.

A mature Hilsa shad lays 0.1-2.0 million eggs in fresh water.

Hatching takes place in about 23 to 26 hours at an average temperature of 23 C.

Hilsha : Bengali delicacy

Migration of mammalsAmong 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

Few migrant animals die of starvation

•The blue wildebeest migrates annually from Kenya to northern South Africa.

•About 250000 wildebeests die each year when they cross the Grameti River.

•They become the chief source of food for Nile crocodiles.

•The crocodiles feed only once a year, when blue wildebeests arrive during their annual migration.

Migrating Wildebeest

• 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.

•Those living on Victoria Island during the summer, migrate to the mainland in the fall after the sea ice has formed.

Caribou : The Reindeer

Massive Migration The Mali Elephant takes

on the longest elephant migration on earth.

• Largest predator found on land.

•The polar bears of Hudson Bay, Canada, arrive on land early in the summer and leave later in the autumn.

•Each October, the Canadian town of Churchill in Manitoba plays host to a thousand hungry polar bears.

Polar Bears: The iconic symbol of Svalbard

Migration of reptiles

Migratory reptiles include leather back turtle Green sea turtle(chelonia)

The leatherback turtle is the record holder, traveling an astounding 10,000 miles. Crosses the entire Pacific Ocean from Asia to the West Coast of US .

Green sea turtles migrate 2000 miles to reach their spawning grounds. Mature turtles often return to the exact beach from which they hatched.

Sea Turtle Migration

Migration of amphibiansAmphibians also show long distance migration California newt,breeds in pools in mountain streams in spring and spend in summer months underground In the rain fall and winter ,the newts wander widely over the forest floor in search of insect food.In spring adult migrate back to the stream.

Migration of invertebratesAtlantic lobsters

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.

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.

Monarch butterfly : Born To Move

Lets allow Them to Continue

their Journey a little Longer..

Thank you