Habitat is a fundamental niche which refers to the multidimensional space with proximate factors. Habitat provides shelter, food, protection, mates, space for breeding, feeding, resting, roosting, courtship, grooming, sleeping etc.

1. T Y B Sc. Zoology Notes: Paper IV –Animal BEhavior
To live in a habitat an animal must first have access to the habitat. Once the animal has access to the
habitat it must be able to tolerate the conditions of the habitat and find the resources that it needs to
survive in that habitat. Animals must be able to tolerate at least two kinds of factors in the habitat.
These factors are abiotic factors and biotic factors. Abiotic factors are non-biological factors such as
temperature, humidity, salinity and pH to name a few. Biotic factors are biological factors such as
competition, predation, and disease. If both abiotic and biotic factors can be tolerated the animal must
also be able to find the resources that it needs to survive. Habitat is a fundamental niche which refers to
the multidimensional space with proximate factors. Habitat provides shelter, food, protection, mates,
space for breeding, feeding, resting, roosting, courtship, grooming, sleeping etc. Birds are nearly ideal
subjects for studies of habitat selection, because they are highly mobile, often migrating thousands of
miles (and in the process passing over an enormous range of environments), and yet ordinarily forage,
breed, and winter in very specific habitats. The small migrant songbirds are well known for habitat
choices -- where to feed, where to seek a mate, where to build a nest, where to stop to replenish
depleted stores of fat when migrating, and so on. Choices can be so finely tuned that often the two
sexes of a species use habitats differently. In grassland, male Henslow's Sparrows forage farther from
the nest than females; in woodlands, female Red-eyed Vireos seek their food closer to the height of
their nest (10-30 feet), and males forage closer to the height of their song perches (20-60 feet).
Animals live in competitive world. Two species or more occur in a single habitat, in which they strive for
survival, shelter, food; space etc. there may be considerable competition, predation, diseases,
allelopathic agents (antibiosis/ poisoning) in the existing habitat.
Every available space cannot play a role of habitat for all species at a time due to certain antagonistic
factors. Therefore the animals select the habitat which fulfils its niche and keeps it away from other
antagonistic factors.
I. Effect of different factors on habitat selection:
Factors like behavior of organisms, physicochemical factors, genetics, phylogeny etc. are responsible
for the habitat selection.
a. Behavior of organisms-
Different behavioral pattern of organisms make them to select a definite habitat. A species
finalizes the suitable habitat after vigorous interaction amongst other organisms.
By Prof. S D Rathod
Dept. of Zoology
B N Bandodkar College of Science, Thane, India

2. T Y B Sc. Zoology Notes: Paper IV –Animal BEhavior
i. Prey species: The predators are confined to the habitat where their prey population is
available in abundance. E.g. predatory birds are seen near the insect population.
Kingfisher prefers the habitat near ponds or lakes where fishes are abundant.
ii. Competitors: Many species having similar niche are competitors. They avoid the
competition by sharing the habitat e.g. tree pipit prefers the dense trees whereas
meadow pipit lives in the bushes of grassy areas.
iii. Allelopathic agents: Certain organisms repel
others by secreting harmful or unpleasant
chemicals to occupy the area. The intolerant
species more other places and select other
habitats. E.g. Noctiluca sp. Secret toxic chemicals
hence other zooplankton are not found in this
area. Fungi secret antibiotic keeping other micro-
organisms away from the habitat.
iv. Predators: Excessive pressure of predation may make prey species to move to other
comparatively more safe habitats. Or the prey species is eradicated due to the high
predation pressure from the areas and flourish in the other less sever habitat.
b. Physical and chemical factors- Organisms are very sensitive to the physic-chemical factors,
predominantly the temperature and moisture. The factors like temperature, moisture, light, pH,
humidity, soil texture, fire, oxygen, soil fertility, salts etc. will decide the species to be living in a
habitat. The compatible species to the existing factors will survive in a habitat. Animals select
By Prof. S D Rathod
Dept. of Zoology
B N Bandodkar College of Science, Thane, India

3. T Y B Sc. Zoology Notes: Paper IV –Animal BEhavior
the habitat of their physiological tolerance e.g. woodland deer mice select forest rather than
crop fields, because they cannot tolerate the high temperature in the field. Within the forest
they may prefer to live in large trees like oak or beech where they get more food as acorns and
beechnuts in addition to better shelter and more nest sites. Phytoplankton flourish at surface
near shore of the oceans where the ample sunlight for photosynthesis and nutrients for their
growth occur.
c. Genetic relationship- Living beings have evolved with the available environment, thus have
phylogenetic relationship. Sometimes the different species although having capacity to live in
variety of habitats they are typically confined to one of those. E.g. coal tits select only pine trees
where as blue tits select oak trees.
d. Early experience- Organisms having experience in different habitats, select the one out of
many which is best secured for their survival. This knowledge they gain from experience.
e. Microhabitats- Some small organisms like
flies, ants, termites, aphids have to select
certain microhabitat which provides them the
life commodities. E.g. Drosophila selects
habitat of high humidity. Aphids select broad
leaves on cotton wood tree where their
reproductive success is high. O’Neil (1967)
found seven spp. of millipedes in a maple
forest. All were detritivores and living in same
habitat. But detailed research revealed that
each species dominated in its own specific microhabitat, which was different from the others.
The microhabitat of each species was comprised of a particular gradient of detritus which they
preferred as compared to other species.
By Prof. S D Rathod
Dept. of Zoology
B N Bandodkar College of Science, Thane, India

4. T Y B Sc. Zoology Notes: Paper IV –Animal BEhavior
II. Model example:
No two species living in the same general habitat can occupy identically the same ecological niche.
Other example is dependent on the tradition of their behavior. Three similar species of ungulates
live in different habitats in a forest. ‘Sambar’ (dancing deer) prefers the hilly terrain and ‘chital’
(spotted deer) prefers the dense forest with large trees whereas the ‘Kalwit’ (blackbuck) selects the
open savanna in Indian forest.
Dancing Deer (Sambar) Spotted Deer (Chital)
By Prof. S D Rathod
Dept. of Zoology
B N Bandodkar College of Science, Thane, India