This document discusses four main types of population interactions: predator-prey, herbivory, competition, and symbiosis. It also defines four special species types: dominant species, nonnative species, keystone species, and ecosystem engineers. Examples are provided for each type of population interaction and special species. Key concepts are underlined and vocabulary defined in green.

1. 12-6-16
Advanced Biology
Species Types and Interactions

2. 1. Distinguish between the 4 main
types of population interactions
2. Distinguish between the 4 main
types of special species
• Objective

3. AS ALWAYS DEAR STUDENTS…
KEY CONCEPTS ARE UNDERLINED
VOCABULARY IN GREEN

4. • Niche – an organisms role in a
community; what it eats, what
eats it, what interactions it has
with other populations
• Habitat – where an organism
lives

7. Population interactions 1. Predator-prey:
a relationship
where one
organism (the
predator) eats the
other (prey)
• +/-

8. – Predator-prey interactions have resulted in unique
adaptations
• camouflage
• warning colors
• mimicry

9. 2 rules about coloration
• Small + beautiful = poisonous
• Beautiful + easy to catch = deadly

10. Aposematic coloration-
poison arrow frog
Batesian mimicry Mullerian mimicry

11. 2. Herbivory: +/- interaction; an herbivore eats a
plant or algae
– many plants possess adaptations that help them
avoid herbivory
Strychnos toxifera is a vine that produces strychnine

12. Population interactions
3. Competition – when
two or more
organisms need the
same resource at the
same time
• -/-

13. • Intraspecific competition – same species fight
to win a resource

14. • Interspecific competition – different species,
usually no fighting

15. Population Interactions
4. Symbiosis – when two or more different
species live in close physical contact with each
other

16. 4a)
Parasitism
• A form of symbiosis in
which one organism
benefits and the other is
hurt

17. 4b)
Mutualism
• A form of
symbiosis in
which both
organisms benefit

18. 4c)
Commensalism
• A form of symbiosis
in which one
organism benefits
and the other is not
harmed or helped

19. You try
What type(s) of population
interaction(s) are at work here?
• Herds of zebra and
flocks of ostriches
often feed and move
together across
grasslands. Zebras can
fight off predators
more effectively that
an ostrich and
ostriches can stand
taller and see farther
across the plains.

20. You try
What type(s) of population interaction(s) are at work here?
• Honey badgers eat a
wide variety of foods
including honey from
beehives when they can
find one. Honeyguides
eat honeybees and their
larvae. When a
honeyguide finds a hive it
seeks out a badger and
makes a loud call. As the
badger rips into the hive,
then bird eats the bees.

21. You try
What type(s) of population interaction(s) are at work here?
• False scorpions
are very tiny and
feed on small
insects
• They have no
means of travel
except their very
short legs, so
sometimes they
hitch rides on
other animals,
like this beetle

22. You try
What type(s) of population interaction(s) are at work here?
• Sooty shearwaters are
seabirds that dig burrows
in soft soil to lay their
eggs. Both parents take
turns caring for the egg.
Sometimes, a tuatara will
take over the burrow
while the parents are out
feeding. They may eat the
egg or chick, and keep the
parents from getting back
in the burrow.

23. Special Species Types – species that
affect the biodiversity of the
ecosystem

24. 1. Dominant species –the most abundant or highest biomass species in
an ecosystem

25. 2. Nonnative species
• Aka alien, invasive, exotic
• Accidentally or deliberately introduced species

26. • Often the non-native species has no natural
predators and takes over the ecosystem

27. 3. Keystone species
• Have a large effect on the number and type of
other species in the ecosystem

28. Examples:
• Top predators - feed on and help regulate the
size of other populations
• Pollinators - control the size of plant
populations

29. Effects of losing a keystone species
• When a keystone species is lost - it leads to
population crashes and extinctions of other
species

30. 4. ecosystem engineers
• Aka foundation species
• Play a major role in creating the
ecosystems in which they live

31. Examples:
• Elephants pull out or break small trees in
the African savannah
• This allows grass to grow and benefits other
grazers and open plains predators

32. Examples:
• Beavers - build dams to create ponds that
other species benefit from

33. What species type(s) is this an example of?
• Sea stars are the
main predator of
mussels. When sea
star populations
decrease, mussel
populations expand
rapidly and take
over most of the
rock surfaces,
crowding out other
species like urchins,
crabs, and limpets

34. What species type is this an example of?
• In the forests of Patagoinia, the Firecrown
Hummingbird is the sole pollinator for nearly
20% of the local plant species

35. What species type is this an example of?
• Kudzu vine was brought
from Asia to the United
States in the late 1800s. It
was uses as cattle fodder
and as a way to control soil
erosion. The plant grows
very quickly (~1 foot/day)
and is able to outcompete
other plant species. It can
kill trees by growing over
and completely covering
them. The USA spends $6
millions every year fighting
kudzu with pesticides and
removal

36. What species type is this an example of?
• The Indian Crested
Porcupine digs for
roots and tubers in
the ground, creating
large pits that remain
for a long time.
These pits fill with
dead organic matter
and make small
patches of fertilizer
that help more trees
grow in the area

37. What species type is this an example of?
• Mangrove forests grow
in tropical and
subtropical area and are
made up mostly of
mangrove trees. The
tree roots act as shelter
for small organisms
hiding from predators.
Many aquatic animals
have their babies or lay
their eggs here so the
young can be protected
by hiding among the
tree roots