Transcript Predation - Ning.com

What is a Community
A Community is any assemblage of populations in
an area or habitat.
Communities: Populations interacting; Population interactions
shape communities.
Communities are
characterized by the
interactions among
their component
populations.
In this scene,
vultures wait for
whatever will
remain of a lion’s
zebra kill.
Yucca community : A web of Interdependence. The mule deer and sap beetle
eat yucca flowers, while the ash-throated flycatcher picks off yucca moths. Belowground, the yucca roots release a soaplike substance that makes scarce water more
available for itself and its nitrogen-fixing neighbors.
A
B
Coevolution between the yucca moth and the yucca plant.
(A) A female yucca moth (Tegeticula yuccasella) pushing
pollen into the stigma tube of the yucca flower while
visiting the flower to deposit her eggs. (B) Yucca moth
larvae feeding on seeds in the yucca fruit.
http://www.britannica.com/ebc/art/print?id=20&articleTypeId=0
Strange Community of Aquatic Organisms Discovered in the Deep-Ocean
Abyss. In 1977, scientists discovered an entirely new ecosystem based on the heat
energy from hydrothermal vents. The living community in this physical setting
included yellow vent mussels, crabs (here, looking like ghostly white spiders), large
vent clams, and tube worms with red plumes. These plumes take in oxygen, and the
worm’s body contains chemoautotrophic bacteria, which produce fixed carbon
compounds in this ecosystem.
Characteristics of a Community
• Diversity
– species richness (total number of
different species)
– Relative Abundance of different
species.
• Prevalent form of vegetation.
• Stability – communities ability to resist
change and recover from disturbance.
• Trophic structure
Biodiversity
• Species
Richness vs.
Relative
abundance
A population is a group of organisms of the same species, which live in the
same place at the same time, and can interbreed with each other. --Interacting individuals of the same species
A community is the organisms of two or more populations of different
species occupying the same geographical area, and the interaction between
those species. Interacting populations of different species
An ecosystem is the interrelationship between organisms and the
environment in which they live. A community of species interacting with
their physical environment
A habitat is a place where an organisms lives. Home or address
The niche is a role, function, or position of an organism in a biological
community. Job – how it gets its supply of energy and materials
Fundamental niche is the potential range of all environmental conditions
under which an organism can thrive.
Realized niche is the part of the fundamental niche that a species actually
occupies in nature.
Ecological Niches
• The total of a species’ use of biotic and abiotic resources is called the
species’ ecological niche
• Ecologically similar species can coexist in a community if there are one
or more significant differences in their niches
• As a result of competition, a species’ fundamental niche may differ from
its realized niche
• An organism’s niche is its role in the environment
• 2 species cannot coexist if their niches are identical
• Resource partitioning – differentiation of niches that enable two similar
species to coexist in a community
The Ecological Niche
The sum total of a species use of the biotic
and abiotic resources in its environment
Fundamental Niche
– The theoretical maximum resources that
could be used by a population.
Realized Niche
– The actual resources that are used by a
population.
Page 712
Niche :
An Organism’s Role in the Community.
(a) The fundamental niche is the full range of
conditions under which a given organism can
operate. As depicted here, a forest warbler can
catch insects in a tree at any height and on
branches any distance from the trunk, and it can
nest any time between early June and late July.
(b) The realized niche is the part of the
fundamental niche that the organism actually
occupies. The Cape May warbler catches insects
only in the outer branches toward the top of the
tree, and it nests only in June. The bay-breasted
and myrtle warbles feed in different places and
nest at different times, and thus occupy separate
realized niches within the boundaries of the
fundamental niche.
Interspecific Interactions
Interspecific Interactions
• Competition
• Predation
• Symbiosis
– Parasitism
– Mutualism
– Commensalism
Competition between species for limited resources:
Interspecific competition – the use of the same
resources by 2 different species, --- one or both
competitors have a negative effect on the other’s
survival or reproduction
Competitive exclusion – a situation where one
species eliminates another through competition
--Two species cannot indefinitely occupy the same
ecological niche. The one that is more efficient in taking
advantage of available resources will exclude the other.
--Two species cannot coexist when they have identical
needs of a limited resource.
Page 713 - 714
Interactions between Organisms
Competition results when organisms require the same
limited resource.
Competitive exclusion
The theory that populations of two species competing for
a limited resource can not coexist indefinitely in the same
habitat.
Example: Lemna polyrhiza grew individually faster than L. gibba.
When the two were grown together L. polyrhiza was always
replaced by L. gibba. L. gibba – airsacs to float over L polyrhiza,
cutting off the light.
Competition between species for limited resources:
Competitive exclusion
G. F. Gause, Russian biologist, 1934 – designed a laboratory experiment,
Competition between Paramecium species for the same resources (bacterial
cells) in the same culture.
Competition between species for limited resources:
Competitive exclusion
P. caudatum – large celled sp (lcs) and
P. aurelia – small celled sp (scs)
-- grew each sp in its own container –
population growth reflected the
standard S-shaped curve
-- grew them in the same container – interspecific competition
occurred and the smaller celled sp drove the larger celled sp to
extinction
Reasons: scs 1 was more resistant to bacterial waste products than lcs
2 reproduced more rapidly than lcs
Natural causes of Competitive Exclusion
1. Resource (Exploitation) competition = Occurs when use of a
resource by one individual/population/species reduces the
availability of that resource to other individuals/populations.
(Two sp. exploit and have equal access to identical
resources)
2. Interference competition = Competition between two
individuals/populations/species in which one physically or
chemically excludes the other from a portion of habitat and
hence from the resources that could be exploited there. (The
use of aggressive behavior to keep competitors from a
resources)
Page 714
How have some species reduced or
avoided competition
• Resource partitioning - dividing up the
scarce resources so that species with
similar requirements use them at different
times, in different ways, or in different
places.
• Ex. If lions and leopard live in the same
area the lions take the bigger prey while the
leopards take the smaller
Page 715, and Fig. 35.6
A. insolitus
usually perches
on shady branches.
A. ricordii
A. distichus
perches on
fence posts
and other
sunny
surfaces.
A. insolitus
A. aliniger
A. distichus
A. christophei
A. cybotes
A. etheridgei
Seven species of Anolis lizards live in close
proximity at La Palma in the Dominican
Republic.
Character Displacement
Character displacement is a tendency for characteristics to
be more divergent in sympatric populations of two
species than in allopatric populations of the same two
species
Ex. Anolis lizards split up the territory and occupy a
different niche as their hereditary changes in physical
and behavior characteristic. Such change is called
character displacement.
Character displacement is an example of coevolution,
heredity changes in two or more species as a
consequence of their interactions within a community.
Character displacement brings about a partitioning of
resources by competing species.
Resource Partitioning
Interspecific Interactions
• Competition
• Predation - page 716
• Symbiosis
– Parasitism
– Mutualism
– Commensalism
Predation
• Animals eating animals
• Animals eating Plants - herbivory
• Parasitism - parasite feeding on body
fluids of host.
Interactions between Organisms
Predation refers to interaction where one species, the
predator, kills and eats the other, the prey.
Some feeding adaptations of predators are claws,
teeth, fangs, stingers, and poison
Predators that pursue their prey are selected for speed and
intelligence.
Carnivores store information about the prey’s escape
strategies and must make quick choice while in pursuit
Predation and parasitism directly benefit one species (the
predator or parasite) and directly harm the other (the prey or host).
Predator Adaptations
• Acute Senses - Smell, Eyesight, Hearing.
Interactions between organisms
Predation:
Predator and Prey
Genetic changes in response to natural selection
resulting in a grand co-evolution race, with predators
evolving more efficient ways to catch prey and prey
evolving ways to escape.
Predator needs a way to catch its food – pursuit and ambush
Predator-Prey and Parasite-Host Coevolution:
The relationships between predator and prey, and parasites and
hosts, have coevolved over long periods of time.
Predation
Predation- when an organism captures and feeds on another organism.
Predators tend to be larger than their prey, and consume many prey
during their lifetimes.
Predator- hunter; Prey- hunted
Prey and Defense (page 719)
Prey species have various forms of
protection. They can run, jump, swim or
fly. Some have developed keen eyesight or
sense of smell that alerts them to the
presence of predators
Prey display various defensive adaptations
Behavioral defenses include hiding, fleeing, selfdefense, and alarm calls
Animals also have morphological and physiological
defense adaptations
Plant Defenses Against Herbivores
• Chemicals, Crystals, Thorns.
Animal Adaptations against Predators
• Passive defenses - hiding
• Active defenses - running away
Insect Camouflage and Mimicry are adaptations
Self - Protection: Camouflage and Mimicry
Avoiding Predation -- minimize the risk of being preyed upon
Camouflage comes from the French word camouflager which
means to "blind or veil".
Camouflage, called cryptic coloration – an outcome of an
organism’s form, patterning, color or behavior that helps it
blend with its surroundings and escape detection.
An animal that uses camouflage looks like things in its
environment. It might look like a leaf, a twig, or a rock.
Mimicry – the evolution of similar appearance in two or
more species, which often gives one or all protection.
Animals that use mimicry use colors and markings to look
like another animal.
WARNING AND MIMICRY
• Predator deterrent evolves
• Warning
– color of bees & wasps
– coral snakes
– monarch butterflies
• Convergence in warning – Mullerian Mimicry
• Copy the warning without the deterrent Batesian Mimicry
– moths & flies
– king snakes
– viceroy butterfly
Defensive Mechanisms
• Batesian Mimicry - Harmless species evolve characteristics that mimic
unpalatable, dangerous or poisonous species
– Viceroy and Monarch butterfly
• Mullerian Mimicry - Two unpalatable species evolve to look alike
– Bees and Wasps
• Camouflage
• Advertising and warning (coral snake)
• Attracting prey, pollinators, mates, etc.
Cryptic Coloration
(camouflage)
Occurrence of shapes, colors, patterns or even behaviors that
enable organisms to blend in with their background.
One defense strategy avoids confrontation through camouflage.
Cryptic Coloration, making a potential prey difficult to spot against its background.
Cryptic Katydids: Katydids camouflage to a wide variety of environments.
Can you find the katydid in each picture?
http://www.thewildones.org/Animals/camo.html
The motionless twig caterpillar complete
with "buds" and "lenticels" escapes detection
by birds (but pays for its cleverness by
occasionally having some other insect lay
Walking sticks have adapted to
eggs on it by mistake).
resemble their surroundings. Most
of the time, their predators pass
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mimicry.html
them by as they would a real twig.
Aretaon asperrimus. This
appears to be a moss and lichen
mimic, and blends in well, if you
don't already know something is
there
Phyllium bioculatum
http://www.bugsincyberspace.com/mimicry_and_camouflage.html
http://www.bugsincyberspace.com/mimicry_and_camouflage.html
Deceptive coloration
Another form of adaptive coloration, large fake eye or false head
can apparently deceive predators momentarily, allowing the prey
to escape.
Large eye spots that make them look like scary animals and frighten
predators away.
Eyespots: Io Moth (Automeris io)
http://www.fieldmuseum.org/butterfly/thumb10.htm
Eyespots: Common Buckeye
Junonia coenia
Sometimes harmless insects look ferocious, frightening
their enemies.
Hickory horned devil, large caterpillar scares away its
enemies by its appearance
Aposematic Coloration, Warning colors
Animals with effective physical or chemical defense often exhibit
bright warning coloration, called aposematic coloration.
Poisonous prey species
usually evolve brightly
colored patterns, enabling
the experienced predator to
recognize and avoid them.
Mimicry is a different type of camouflage. Animals do not
try to blend in with their surroundings, but instead mimic a
different type of animal.
Many nonpoisonous prey species masquerade as poisonous
species.
Ex. A number of harmless snakes have evolved very similar
coloration to highly poisonous snakes. Many types of harmless,
stingless flies have evolved a very similar appearance to bees
and wasps.
Aposematic coloration
Monarch butterfly
Danaus plexippus
Bright warning coloration and mimicry occur in many
groups of butterflies. The monarch caterpillar feeds on
milkweed, which makes the adult butterfly bitter and
poisonous to birds. Birds learn quickly to avoid its bright
orange and black pattern.
Batesian mimicry
• Monarch Butterfly – Toxic
model
•
•
•
•
•
•
• Viceroy Butterfly –
Harmless mimic.
Batesian mimicry, a palatable species mimics an
unpalatable model.
Monarch Danaus plexippus
Viceroy Limenitis archippus
The viceroy butterfly, on the other hand, is better tasting, but
still unpleasant. Because its orange color and black stripes are
like the colors of the monarch, birds learn to avoid both at once
-- butterflies of both species and the birds benefit!
http://www.fieldmuseum.org/butterfly/thumb5.htm
Batesian mimicry
Many animals that
eat spiders find ants
distasteful. The antmimic spider is more
likely to survive
because it resembles
its two less-edible
ant companions.
Batesian Mimicry
A palatable or harmless species mimics an unpalatable or
harmful model.
Hawk Moth Mimicry: This moth caterpillar defends itself by mimicing a snake.
The back of the hawk moth caterpillar actually looks like a
snake head, a frightening visage for most predators the moth
would come across.
Mullerian Mimicry
• Two or more unpalatable species resemble
each other
Aggressive Mimicry
Some carnivores have evolved devices with which they mimic the prey (or potential
mate) of other (usually smaller) predators. They use these devices as lures.
The angler fish (Antennarius)
displays a lure resembling a small
fish. The lure is a development of
the spine of the first dorsal fin. This
species of anglerfish, which was
found in the Philippines, is 9.5 cm
long. Note its use of camouflage: its
texture (and color) closely resemble
the sponge- and algae-encrusted
rocks found in its habitat.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mimicry.html
Chemical warfare
Bombardier beetle
http://www.talkorigins.org/faqs/bombardier.html
The beetle emits an evil-smelling fluid
from its abdomen, as a defence
mechanism. This fluid rapidly evaporates
into a gas, which appears like a minute jet
of smoke when in contact with air, and
blinds the predator about to attack.
Classification
Bombardier beetles in genus Brachinus,
family Carabidae, order Coleoptera, class
Insecta, phylum Arthropoda.
Page 721
http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0063590.html
the African Stenaptinus insignis
Eisner and Aneshansley (1999), Spray
aiming in the bombardier beetle:
Photographic evidence, Proc. Natl. Acad.
Sci. (96).
Jakobs and Renner (1988), Biologie und
Okologie der insecten: Ein Taschelexikon
http://www.math.canterbury.ac.nz/~afj15/BEETLES/beetles.html
Interspecific Interactions
• Competition
• Predation
• Symbiosis – (page 721), any relationship where two
species live closely together. (3 types)
– Parasitism
– Mutualism
– Commensalism
Interactions between organisms
Parasitism
Parasites: the intimate predators
Ectoparasites and Endoparasites
Sometimes, parasites -- less harmful to the host
Ex. Native antelope in Africa -- tolerance to trypanosomes
which cause lethal cases of sleeping sickness in domestic
cattle.
Parasitism
• In parasitism, one organism, the parasite,
derives nourishment from another organism,
its host, which is harmed in the process
• Parasitism exerts substantial influence on
populations and the structure of communities
Parasites and Pathogens as Predators
• Parasitism is a symbiotic interaction in with
one organism, the parasite, derives
nourishment from the other organism, the
host.
Interactions between organisms
Parasites: the intimate predators
Cuckoos – social parasitism– one sp exploits the social
behavior of another sp during a critical phase of its life cycle.
Lay an egg in the nest of other bird sp and leave the
foster parents hatch the egg and nurture the young cuckoo baby
Cowbirds – lay their eggs in the nest of oropendolas or large
black birds. Oropendola already accepted the cowbird eggs. The young
cowbirds snapped at adult botflies and picked maggots from the skin of
oropendola nestling. This explain how they would evolve alleles that favor
the acceptance of cowbird egg despite the added cost of an extra mouth to
feed
Parasitic plants.
Tapping phloem sap with an aphid. Aphids feeding on rosebuds. HERBIVORE
A parasitoid is an organism that spends a
significant portion of its life history attached to or
within a single host organism which it ultimately
kills (and often consumes) in the process. Thus
Parasitoids hunt their
prey like predators,
but lay their eggs
within the body of a
host, where they
develop like parasites.
Interactions between organisms
Some organisms produce chemicals that inhibit the
growth of the others – Allelopathy
Example: effect of black walnuts (Juglans nigra) on
other plants – tomato (Solanum lycopersicum) and alfafa
(Medicago sativa) wilt when grown near the black
walnuts and the seedlings die if their roots contact walnut
roots.
Interactions between organisms
Plants produce toxic chemicals in response to
herbivores – “chemical warfare”. They are
chemical metabolites.
Helanin by Helenium sp. – a powerful repellent
Pyrethrum by Chrysanthemum – a natural insecticide
Phytoalexins– stimulated by carbohydrate molecule
elicitors from fungi and bacteria
Tannins – gypsy moths and oak trees
Resins – snowshoe hares and paper birch
Interactions between Organisms
Mutualism is an interaction in which both species benefit.
Mycorrhizae are associations between roots and fungi.
Fungi – Zygomycetes, endomycorrhizae
Basdiomycetes, ectomycorrhizae
Plants – vascular plants
Role of fungi – absorption of phosphorus and other nutrients
required by plants
Ectomycorrhizae
Endomycorrhizae
Arbuscular mycorrhizal (AM)
colonization in
Crassocephalum crepidioides
(Benth.) S. Moore (Asteraceae)
from Kra chai dam field:
vesicle and arbuscules
Facultative vs. Obligate Mutualisms
• Facultative Mutualisms are not essential
for the survival of either species.
Individuals of each species engage in
mutualism when the other species is
present.
• Obligate mutualisms are essential for the
survival of one or both species.
CASE STUDY CORALS/ZOOXANTHELLAE
• Corals & anemones (Cnidarians)
have obligate relationship with
dinoflagellates
• If dinoflagellates leave, Cnidarian
dies
• Dinoflagellates get byproducts from
metabolism of cnidarians
• Cnidarians get food from
metabolism of dinoflagellaltes
•
Giant Clam
Tridacna squamosa
•
The mantle (soft tissue) within the
shell is brightly coloured brown,
blue and/or green. This is due to
the microscopic algae known as
zooxanthellae living inside the
tissues which photosynthesise
(manufacture food) from sunlight
and the waste metabolic products
of the clam. They are then
"harvested" by the clam as
supplementary food.
Despite being "farmed" this way,
the algae are assured of a safe
"residence" and a continued
supply of nutrients.
•
Mutualism
Interactions between Organisms
Mutualism is an interaction in which both species benefit.
Acacia trees and ants interact in a mutually beneficial way:
Bull’s acacias, Acacia cornigera
Ants, Pseudomyrmex ferruginea
Mutualistic relationship
Ants and acacias: Pseudomyrmex ferruginea and Acacia
cornigera, Beltian bodies at the tips of acacia leaflets are rich in
protein and oils which are food source for adult and larval ants.
Ant protects the acacia from other insects
Mutualism
• An interspecific
interaction that
benefits both
species
Coevolutionary Partners : The Yucca Moth and Yucca Flowers.
Yucca whipplei, also called Our
Lord’s Candle, grows in the
Mojave Desert and has an intimate
relationship with the yucca moth
(inset). The moth lays its eggs in
the ovary at the base of a yucca
flower and then pollinates the same
flower. Moths depend on the plant
for food and reproduction; the
plant depends on the moth for
pollination. This mutually
beneficial relationship is called
mutualism.
To fix nitrogen:
Nitrogenase catalyses the
conversion of nitrogen
gas to ammonium ion, to
do this, it needs a supply
of hydrogen, ATP and
anaerobic condition.
-Hydrogen from reduced
NADP
-ATP from sucrose by
photosynthesis
-protein by plant called
leghaemoglobin which
has high affinity for
oxygen – mops up
oxygen
Root nodules on a legume. The nodules of this pea root contain
symbiotic bacteria that fix nitrogen and obtain photosynthetic products
supplied from the plant.
Lichens
Association of fungi
and algae in which both
the organisms interwine
to form a single thallus
http://www.nhm.ac.uk/botany/lichen/air/poster.html
Figs have a symbiotic
relationship with
particular species of
wasps. These wasps lay
their eggs in the flowers
of the fruit and in the
process pollinate the
flower for the fig. The
ripening fig then provides
a food source for the
larva of the wasp.
Neither can exist without
the other.
Coevolution
Pseudomyrmex ants have a mutualistic relationship with
certain species of Acacia. The ant protects the plant
against herbivory and the plant provides the ants with
protein, carbohydrate and a place to live
Fig wasps pollinate flowers of the fig plant and in return
the fig provides food and shelter for the larval stage of
the wasps
Protozoa live in the gut of termites and wood roaches
and obtain food from the foraging activities of the
insects. In return, the protozoa use their specialized
enzymes to break down cellulose, a polymer of glucose,
for the insects.
Flower - pollinator relationships
Insect Mimics
http://www.evowiki.org/wiki.phtml?title=Orchid_flowers
Protocooperation
A hermit crab and
the sea anemone
Symbiosis
•
Commensalism – One
member of a symbiotic
relationship benefits and the
other is neither helped or
harmed
•
Ex. Holes used by bluebirds
in a tree were chiseled out by
woodpeckers after it has been
abandoned .
Commensalism
Shark and Remora fish
Caribbean Reef Shark With Remora
Commensalism; One species benefits, the other
doesn't but is not harmed.
Sea anemone and Cartoon Fish
Commensalism: Epiphytes:
Neutralism
Neutralism the most common type of
interspecific interaction. Neither population
affects the other. Any interactions that do
occur are indirect or incidental.
Example: the tarantulas living in a desert and
the cacti living in a desert
Amensalism
Amensalism is when one member harmed but other
unaffected.
Amensalism is a biological interaction between two species in
which one impedes or restricts the success of the other without
being affected positively or negatively by its presence. It is a type
of symbiosis.
Usually this occurs when one organism exudes a chemical
compound as part of its normal metabolism that is detrimental to
another organism.
The bread mold Penicillium is a common example of
this; penicillium secrete penicillin, a chemical that
kills bacteria.
Amensalism
Antibiosis
Epicoccum nigrum and
Sclerotinia sclerotiorum
Antibiosis test of bacteria
Interspecific relations
Relation
Species A
Species B
Neutralism
0
0
Commensalism
+
0
Protocooperation
+
+
Free relation
Mutualism (symbiosis)
+
+
Closed relation
Amensalism
0
–
Sp. A produces compounds
harmful for Sp. B
Parasitism
+
–
Predation
+
–
Competition
+
–
Neither effects the other
Keystone Species
What Is a Keystone Species?
A keystone species is a species that has a major influence on
the structure of an ecosystem. Its presence impacts many
other members of the ecosystem, and if its population
dwindles or disappears, there can be far-reaching
consequences for the ecosystem.
Keystone species help to support
the ecosystem (entire community of
life) of which they are a part.
For instance, removal of a certain
species of starfish caused a rapid
growth in the numbers and biomass
of mussel upon which the starfish
fed.
Figs are an important food source for a variety of birds,
mammals and insects consequently they are generally
classified as being 'key stone' species.
www.anhs.com.au/cluster%20fig.htm
Predation, Parasitism, Herbivory
• Predators, parasites, parasitoids, and herbivores obtain food at the
expense of their hosts or prey.
Ecological
Succession
• Primary
Succession lifeless area
where no soil
has formed
What is "ecological succession"?
"Ecological succession" is the observed process
of change in the species structure of an ecological
community over time.
Why does "ecological succession" occur?
Every species has a set of environmental conditions
under which it will grow and reproduce most
optimally.
Does ecological succession ever stop?
There is a concept in ecological succession called the
"climax" community. The climax community
represents a stable end product of the successional
sequence.
Disturbance
• Stability? Tendency of a community to
reach and maintain an equilibrium.
Nonequilibrium Model ? Communities are
constantly changing after being disturbed.
Secondary Succession
• Occurs where an existing community has been
cleared by some disturbance
Succession of plant species on abandoned fields in North Carolina. Pioneer
species consist of a variety of annual plants. This successional stage is then
followed by communities of perennials and grasses, shrubs, softwood trees
and shrubs, and finally hardwood trees and shrubs. This succession takes
about 120 years to go from the pioneer stage to the climax community.
http://www.physicalgeography.net/fundamentals/9i.html