Post on 30-Nov-2014
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Principles of Ecologybio 271
dr.Abdulhadi Aloufi
8th lecturewww.draloufi.com
The law of tolerance states that “For each abiotic factor, an organism has a range of tolerances within which it can survive.”
Law of Tolerance
Tolerance range
Optimum range
Unavailable niche
Marginal niche
Num
ber of organism
s
Preferred niche
Marginal niche
Unavailable niche
An organism’s habitat is the physical place or
environment in which it lives.
Habitat
Lichens are found on rocks, trees, and bare ground.
Most frogs, like this leopard frog, live in or near fresh water, but a few can survive in arid habitats.
The habitat provides organisms
with the following resources:
—Food and water sources
—Mating sites
—Nesting sites
—Predator avoidance
—Shelter from climatic extremes
Resources in a Habitat
An adaptation is an inherited
feature of an organism that enables
it to survive and reproduce in its
habitat.
Adaptations
Osprey: a diurnal bird of prey
Spotted owl: a nocturnal bird of prey
1. Structural adaptations: physical features of an organism, e.g. presence of
wings for flight.
2. Behavioral adaptations:the way an organism acts, e.g. mantid behavior when seeking, capturing, and manipulating prey.
3. Functional (physiological) adaptations:those involving physiological processes, e.g. the female mantid produces a frothy liquid to surround and protect the groups of eggs she lays.
Types of Adaptations
Structural Adaptations in Rabbits
Structural adaptations
Widely spaced eyes gives a wide field of vision for surveillance of the habitat and
detection of danger.
Long, mobile ears enable acute detection of sounds from many angles for predator
detection.
Long, strong hind legs andlarge feet enable rapid movement
and are well suited to digging.
Cryptic coloration provideseffective camouflage in
grassland habitat.
Functional Adaptations in Rabbits
Functional adaptations
High reproductive rate enables rapid population increases when food is available.
Keen sense of smell allows detection of potential threats from predators and from rabbits from
other warrens.
Microbial digestion of vegetation in the hindgut enables more efficient digestion of cellulose.
High metabolic rate and fast response times enables rapid response to dangers.
Hawks are major predators of rabbits
Behavioral Adaptations in Rabbits
Behavioral adaptationsFreeze behavior when startled reduces the
possibility of detection by wandering predators.
Thumps the ground with hind legs to warn others in the warren of impending danger.
Lives in groups with a well organized social structure that facilitates cooperative defense.
Burrowing activity provides extensive underground habitat as refuge from
predators.
Freezing is a typical behavior when threatened
The home range is the physical area of an organism’s normal activity. It provides all of the resources required for the organism’s survival.
Home Range=Territory
Marking a Home Range
The boundaries of a home range may be marked by:
1. calls and displays
2. scent marking, urination, defecation
3. scratching, biting, or rubbing on vegetation.
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