This document discusses ecological niches and the relationships between organisms and their environments. It defines key terms like ecology, biotic and abiotic factors, and ecological niche. An ecological niche refers to an organism's role and position in its environment, including what it eats, habitat requirements, and tolerance of environmental conditions. The document contrasts fundamental and realized niches, and explains Hutchinson's niche concept and Gause's competitive exclusion principle. Examples are provided of how different species occupy different niches to avoid competition, such as various finch species on the Galapagos Islands. Habitat is defined as the actual environment an organism lives in, while niche refers more to the specific requirements that allow it to survive and reproduce.

1. Ecological Niche
Aqil Qureshi
BS (hons) Zoology

2. Ecological Niche
Ecology:
The branch of biology that deals with the relation of
organisms to one another and to their environment.

3. Environment
The surrounding or conditions in which a persons,
animals or plants live .
Factors of environment
 Biotic Factors
 Abiotic Factors

4. Difference b/w Biotic and Abiotic Factors
 Biotic Factors
• The living parts of an
ecosystem are called
biotic components
• plants, animals, birds,
fungi etc.
 Abiotic Factors
• The non-living parts of
an ecosystem are
called abiotic or non-
biotic components.
• Sunlight, temperature
Water, air, soil etc.

5. Biotic Factors
Abiotic Factors

6. Ecological Niche
The role and position of a species in its environment
 Energy
 Nutrition
 Timing of activity
 What they eat
 Nest
 Condition of temperature & moisture
Factors

7. We are also filling a niche

8. Typical Habitat

9. Temperature Factors

10. Tree
White Grubs Serpentine Leafminer

11. Red eyed tree frog

12. Discovery
Charles Elden (1917)
Plant occupy own ecological niche
Mistletoe on Eucalyptus

13. Hutchinson niche concept
A description of the ecological space occupied
by a specie .
Types of Ecological Niche
Fundamental Niche
 Realized Niche

14. Fundamental Niche Realized Niche
 Range of environmental
conditions in which each
of the species survive
and reproduce.
 It is larger.
 Elaborate various roles of
species.
 Full niches of species.
 Range of
environmental
conditions in which a
specie is really
found.
 It is smaller
 Portion of
fundamental niche
that is actually filled.

15. Competitive exclusion principle
Also called as Gause’s law because “Georgy
Gause “describe this term.
“Two species can not occupy the same niche”
a. Competition for food
b. Competition for habitat
Definition

17. Paramecium Caudatum Paramecium Aurelia

18. Habitat VS Niche
Habitat
• Actually where the organisms live including biotic and abiotic
factors.
• All of the parameters.
• Address of the organisms.
Niche
• All the factors which an organism require to live and
reproduce in a healthy way in a particular area.
• Selective parameters.
• Profession or job of the organism.

21. Galapagos Islands

22. Warbler Finch Ground Finch
Cactus Finch