Zoogeographers formulate theories to explain the distribution, based on information about geography, physiography, climate, and geologic history, as well as knowledge of the evolutionary history and relationships of the animals involved

1. ZOOGEOGRAPHY
Sharanabasappa M. G.
2018-21-046
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2. Contents
• Introduction
• What is zoogeography?
• Wallace’s line
• Hypothesis of distribution
• Continental Drift hypothesis
• Centre of Origin hypothesis
• Distribution of animals in space and time
• Zoogeographic regions
• Means of dispersal
• Barriers of distribution
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3. Introduction
• What is zoogeography?
Zoogeography, the branch of the science of
biogeography that is concerned with the geographic distribution
of animal species
or
Zoogeography is the study of distribution of animals on
our planet, which occur in different regions of the world in a
distinct pattern
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4. ……Introduction
• Zoogeographers formulate theories to explain the
distribution, based on information about geography,
physiography, climate, and geologic history, as well as
knowledge of the evolutionary history and relationships
of the animals involved
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5. Wallace’s line
• Wallace was the first to realize
that distribution of related
species is fundamentally linked
to geologic history of places the
species inhabit
Alfred Russel Wallace
(1823-1913)
father of biogeography
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6. Hypothesis of distribution
Basically four theories explain the spreading of animals all
over the globe:
1. Continental Drift hypothesis
2. Centre of Origin hypothesis
3. Dispersal
4. Vicariance
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7. Continental Drift hypothesis
Plate tectonics and continental drift
• Plate tectonics is a scientific theory describing the large-
scale motion of seven large plates began on Earth
between 3 and 3.5 billion years ago.
• The concept of continental drift, an idea begins in the
20th century.
• The geoscientific community accepted this theory in the
late 1950s and early 1960s.
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8. ……Continental Drift hypothesis
Continental drift theory
• Wegener thought all the continents were once joined together
in a “Super continent" before breaking up
• He has published the book “The Origin of Continents and
Oceans” in 1915, But geologists not accepted Wegener's
theory of continental drift
Alfred Wegener
(1924–1930)
Super continent
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9. ……..Continental drift theory
• He had noted that fossil remains of the same extinct
animal or plant can be found across several continents
that are not now adjacent to one another
• This suggests that in the distant past, the configuration
of continents was different than it is today, a theory
Wegener called “continental drift.”
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11. Centre of Origin hypothesis
• According to this theory the individuals of a species
spread out from the center of their origin because of their
high reproductive capacity.
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12. Dispersal
Start with one continuous
population. Then, a colonist
floats to an island on a raft.
Finish with two populations
isolated from one another.
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13. Vicariance
1. Start with one continuous
population. Then a chance
event occurs that changes
the landscape (river
changes course).
2. Finish with two populations
isolated from one another.
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14. Distribution of animals in space and time
Distribution in space: Distribution
of animals including land and
water
1) Limnobiotic Distribution: It is
distribution of animals in
fresh water.
2) Holobiotic Distribution:
Distribution of animals in
sea.
3) Geobiotic Distribution:
Distribution of animal on
land.
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15. …...Distribution of animals in space and time
Distribution in Time: The distribution of animal species in
different historic time period of earth is known as distribution in
time.
1. Bipolar Distribution
2. Tropical Distribution
3. Continuous Distribution
4. Discontinuous Distribution
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16. …..Distribution of animals in space and time
1. Bipolar distribution: Number of species which are found
in arctic or Antarctic region
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17. …..Distribution of animals in space and time
2. Tropical Distribution: The distribution of animals in
between the landmass of tropic of cancer and tropic of
Capricorn is called tropical distribution
• This region has maximum bio diversity.
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18. …..Distribution of animals in space and time
3. Continuous Distribution/cosmopolitan distribution: They
have adapted to a wide variety of environmental conditions
and are not specific to any particular environment
conditions
Examples: Rats, Bats, Hawks, cockroaches, flies,
mosquitoes, lizards, snakes and man
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19. …..Distribution of animals in space and time
4. Discontinuous Distribution: When different species of
same genus or different animals of same species are
distributed in different part of earth is called discontinuous
distribution
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20. …….Discontinuous Distribution
1. Animals reach distant areas (insects, snails and rats by
rafting, turtles by floating and swimming and birds blown by
storms)
2. The species was earlier distributed continuously but the
land masses in the intermediate areas submerged,
breaking the species into widely separated populations.
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21. …….Discontinuous Distribution
3. A widely distributed species can become extinct in the
intermediate areas due to change in the climate to which
the species is unable to adapt.
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22. Zoogeographic regions
Philip Sclater (1858) and Alfred Wallace (1876) identified
the main zoogeographic regions of the world used today-
1. Palearctic region
2. Nearctic region
3. Neotropical region
4. Ethiopian region
5. Oriental region
6. Australian region
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23. Palearctic region
• It includes whole of Europe, Russia, China, Japan, North
Sahara, Siberia, Mediterranean Sea zone of North Africa
and Manchuria, south-west Asia, North of Himalayas and
the north of Arabia
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24. ……Palearctic region
• It includes both wet and dry climate
• This region possesses a total of 135 families of terrestrial
vertebrates (33 families of mammals, 68 birds, 24 reptiles, 10
amphibian , 13 freshwater fishes.)
Subdivided into –
1. European sub region
2. Mediterranean sub region
3. Siberian sub region
4. Manchurian sub region
Red panda
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25. ……Palearctic region
Llama
Moose
European salamander
Chinese alligator Heron
Red fox Giant panda Hedge sparrow
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26. Nearctic region
• Includes North America above tropics, Greenland, Iceland and
Mexican plateau.
• Exhibits extreme variations in temperature and varied climatic
conditions.
• Has extensive mountain ranges in the west running from north to
south.
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27. ……..Nearctic region
• This region possesses a total of 120 families of vertebrates (26
families of mammals, 4 birds, 21 reptiles, 14 amphibian , 24 fishes.)
Subdivided into-
1. Californian sub region
2. Rocky Mountain sub region
3. Alleghany sub region
4. Canadian sub region
Red deer
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28. ……..Nearctic region
Pronghorn Turkey Axolotl American salamander
Gila monster Flying squirrel Beaver
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29. Neotropical region
• Includes South America, Central America, tropical lowland of South
Mexico and West Indies.
• Extensive rain forests or evergreen forests are found in Amazon
valley, tracts of dry forests or grassy plains in Savannah and
Argentina, and sub-desert areas are present in western South
America.
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30. …….Neotropical region
• West has long range of Andes which has high mountains.
• Rich in endemic families of all classes.
• The region has 155 families of terrestrial vertebrates, out of which
33 are endemic.
Subdivided into –
1. Chilean sub region
2. Brazilian sub region
3. Mexican sub region
4. Antillean sub region
Anteater
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31. …….Neotropical region
Tapir Armadillo Sloth Marmoset
Tree porcupine Opossums Curassows Cock-of-the-rock
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32. Ethiopian region
• Includes Africa south of Sahara, Madagascar and South
Arabia.
• The Sahara desert acts as an effective barrier between
the Ethiopian region and Palearctic region
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33. ……..Ethiopian region
• There are 161 families of terrestrial vertebrates in this
region.
Subdivided into-
1. East African sub region
2. West African sub region
3. South African sub region
4. Malagasy sub region
Gorilla
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34. ……..Ethiopian region
Slender loris Baboon Ostrich African elephant
Hippopotamus
Giraffe Black bear
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35. ……..Ethiopian region
Golden mole Xenopus sp.
Turacos sp.
Aardvark
African lungfish
Typhlops sp. 35

36. Oriental region
• Includes India, south of Himalayas, Myanmar, Thailand,
Malaysia, Sumatra, Java, Philippines and South China.
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37. …….Oriental region
• Fauna exhibits considerable resemblance with that of
Ethiopian region.
Subdivided into-
1. Indian sub region
2. Indo- China sub region
3. Ceylonese sub region
4. Indo-malayan sub region Pangolin
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38. …….Oriental region
Big-headed turtle
Orangutan Gibbons
Colugo
One horned rhinoceros Shield tail
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39. …….Oriental region
Peacock
Indian elephant
Tarsier
Spiny dormouse
Tree shrew 39

40. Australian region
• Includes Australia, New Zealand, New Guinea,
Tasmania, Moluccas and neighboring islands.
• Region is partly tropical and partly temperate.
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41. …….Australian region
Subdivided into-
1. Austro-malayan sub region
2. Australian sub region
3. Polynesian sub region
4. New Zealand
Kangaroo
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42. …….Australian region
Flying phalanger Spiny anteater
Tiger snake
Australian lungfish
Marsupial mole
Loris
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43. Means of dispersal
1. Land bridges: Land connections between two large land
masses which are separated by sea
• Discontinuous distribution of animals in continents
• It having two types, Corridor bridges and Filter bridges.
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44. ………..Means of dispersal
A. Corridor bridges: land connections of continent size
stretching across oceans and connected two continents
Ex: Gondwanaland existed in Mesozoic, all southern
continents connected by huge corridors across which
animals could freely migrate
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45. ………..Means of dispersal
Corridor bridges:
a. South Atlantic Corridor: This bridge connected with
South America, Africa and also included some islands
(St. Helena, Tristan da Cunha and Ascension)
Ex: It has facilitated spread of lungfish, ostriches,
porcupines and monkeys which are common in both the
continents today
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46. ………..Means of dispersal
b. Lemuria Corridor: The continent of Lemuria is believed to
have existed till early Coenozoic and connected Africa,
Madagascar and India
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47. ………..Means of dispersal
c. Antarctica Corridor: It was largest land bridge that
connected South America with Australia through Antarctica
during Mesozoic
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48. ………..Means of dispersal
d. Panama Corridor: During end Cretaceous North America
and South America were connected by a narrow corridor,
• Through which migrated to the south marsupials and
ancestors of modern ungulates.
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49. ………..Means of dispersal
e. Arctic Corridor: During Mesozoic, Nearctic and
Palaearctic Regions were connected by a broad corridor,
allowing free exchange of marsupials and insectivores
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50. ………..Means of dispersal
B. Filter bridges: Filter bridges are series of islands
between two land masses that allow some animals to
spread across by crossing through swimming, flying, rafting
or through wind
Such a filter bridge now exists between the Oriental and
Australian Regions through Wallacea.
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51. Barriers to dispersal
• Barriers are the factors which hinder in the normal
distribution of animals.
• Barriers can be categorized into 2 categories-
1. Physical barriers
2. Climatic barriers
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52. ……..Barriers to dispersal
Physical barriers
1. Topographical barriers
2. Large water bodies and land masses
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53. ……..Barriers to dispersal
Climatic or Ecological barriers
1. Temperature
2. Moisture
3. Amount of light
4. Vegetation: Giant panda feeds on bamboo shoots in
China and Koala can live only on eucalyptus leaves in
Australia.
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54. Reference
• Philip, D. 1957. Zoogeography: The Geographical
Distribution of Animals. New York: John Wiley & Sons.
• Holt, B. G., Lessard, J. P., Borregaard, M. K. 2012. “An
Update of Wallace’s Zoogeographic Regions of the
World.” Science, 339: 74–78. DOI:10.1126/
science.1228282.
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