Topic 10

Question 1

Ecological community

Answer 1

A group of populations of different species living and interacting in the same place at the same time

Question 2

Community ecology

Answer 2

Study of how species interact with each other (interspecific) and how those interactions shape population sizes, distributions, and biodiversity

Question 3

-/- interaction

Answer 3

Competition

Question 4

+/- interaction

Answer 4

Predation, herbivory, or parasitism

Question 5

+/+ interaction

Answer 5

Mutualism

Question 6

+/0 interaction

Answer 6

Commensalism

Question 7

0/+ interaction

Answer 7

Amensalism

Question 8

Intraspecific competition

Answer 8

Same species competing, density dependent regulation, limits population growth, usually stronger than interspecific

Question 9

Interspecific competition

Answer 9

Different species competing, can affect population size of one of both species, may lead to exclusion or coexistence

Question 10

Predation

Answer 10

Predator kills and eats prey, decreases prey’s survival, can alter prey behaviour, habitat use, stress levels, and life history. Selective predation can take old/sick/young and improve prey fitness. Predator and prey have linked population cycles

Question 11

Herbivory

Answer 11

An animal consumes plant tissue. Usually small and chronic not dramatic. Light grazing can stimulate growth (compensatory growth). Herbivores regulate plant populations and transfer energy to higher trophic levels

Question 12

Parasitism

Answer 12

A symbiotic relationship where one organism benefits at the expense of their host. Not always lethal, it benefits the parasite to keep the host alive. Can be host specific or generalists which can infect many species

Question 13

Ectoparasites

Answer 13

Live on the host

Question 14

Endoparasites

Answer 14

Live in the host

Question 15

Brood parasitism

Answer 15

Some bird species lay eggs in other species nests. The host raises the chick often and the expense of their own offspring

Question 16

Parasitoid

Answer 16

Organism that live in/on a host early in life and eventually kills it. An intermediate between a parasite and a predator.

Question 17

Mutualism

Answer 17

Both organisms experience a net fitness benefit. Often increases productivity and resource availability (nutrient cycling). Builds networks of interconnected species

Question 18

Obligate mutualism

Answer 18

One or both species depend on the interaction for survival or reproduction. Tends to be more specialized and tightly linked

Question 19

Facultative mutualism

Answer 19

Beneficial but not required. Often more flexible and context dependent.

Question 20

Commensalism

Answer 20

One species benefits while the other is unaffected

Question 21

Amensalism

Answer 21

One species is harmed while the other is unaffected. Relatively uncommon

Question 22

Indirect interactions

Answer 22

Occur when individuals do not interact directly but still affect one another through shared resources, predators, or environments

Question 23

Apparent competition

Answer 23

When 2 prey species share a common predator, and increase in one population leads to a larger predator population, which then increases predation on the other. (Holt 1977)

Question 24

Coevolution

Answer 24

Reciprocal evolutionary change in 2 or more species driven by their interactions. Each species acts as a selective pressure on the other when gaining new traits (reciprocal selection)

Question 25

Evolutionary arms race

Answer 25

Cycle of co-evolutionary escalation. One species improved offence, other improves defence, repeat indefinitely.

Question 26

Red queen hypothesis

Answer 26

Organisms must keep evolving just to maintain fitness relative to co evolving partners. Creates escalating adaptions stabilized by trade offs and costs

Question 27

Common predator strategies

Answer 27

-speed and agility -camouflage -cooperative hunting -stealth and ambush -sensory specialization

Question 28

Common prey strategies

Answer 28

-speed and escape behaviours -camouflage -armour (shells, scales, etc) -group vigilance/defence -coordinated escape -visual confusion -chemical and warning defenses

Question 29

Crypsis

Answer 29

Visual anti predator strategy that avoids detection by blending into the environment

Question 30

Batesian mimicry

Answer 30

Visual anti predator strategy where a palatable species mimics the appearance of a toxic species

Question 31

Aposematism

Answer 31

Visual anti predator strategy that uses bright colours as warning colouration

Question 32

Müllerian mimicry

Answer 32

Visual anti predator strategy where two or more toxic species resemble each other (both benefit)

Question 33

Common plant defences against herbivory

Answer 33

-chemical (tannins) -structural (thorns) -Inducible defences after damage -timing/phenology -mutualisms (attract predators of their herbivore)

Question 34

Common herbivore counter adaptions

Answer 34

-detoxification mechanisms -behavioural strategies/selective feeding -morphological traits -tolerance (store toxins) -timing shifts to when defences are lower

Question 35

Low virulence

Answer 35

Host survives but lower transmission rate

Question 36

High virulence

Answer 36

High transmission rate but short infection window and host dies quickly

Question 37

Optimal virulence

Answer 37

Maximizes transmission

Question 38

Context dependent defense

Answer 38

Species only produce defences when predator cues are present to save energy

Question 39

Optimal defence theory

Answer 39

Invest in protection of your most valuable/vulnerable tissues

Question 40

Defence/energy trade offs

Answer 40

Energy spent on defence is not spent on reproduction or growth

Question 41

Competitive exclusion principle

Answer 41

Two organisms with the same needs cannot co exist in the same place forever

Question 42

The plankton paradox

Answer 42

In aquatic systems, dozens or hundreds of plankton species coexist but appear to compete for the same few limiting resources. Why doesn’t one species win?

Question 43

Ecological niche

Answer 43

The full range of conditions and resources a species uses and responds to. Its role in the ecosystem including what it eats, where it lives, when its active, and response to competition and predators

Question 44

Fundamental niche

Answer 44

Range of conditions where a species could survive and reproduce. Usually larger that what a species actually occupies

Question 45

Realized niche

Answer 45

Range of conditions where a species actually lives. Usually smaller that fundamental niche and shrunk by competition, predation, parasitism.

Question 46

Niche partitioning

Answer 46

When competing species divide up resources to reduce competition. Each specializes on a different subset of the shared resource. Reduced interspecific competition.

Question 47

Morphological partitioning

Answer 47

Body shape/size differences allow access to different resource sizes

Question 48

Spatial partitioning

Answer 48

Different micro habitats within the same area each occupied by a different species

Question 49

Dietary partitioning

Answer 49

Closely related predators eat different types of prey

Question 50

Temporal partitioning

Answer 50

Species are active at different times

Question 51

Character displacement

Answer 51

Different traits only appear when species live together. If only one is present the trait remains intermediate

Question 52

Keystone species

Answer 52

A species whose impact on its community is disproportionately large relative to its abundance. Its removal causes dramatic, often unexpected community restructuring and causes trophic cascades. Hard to identify until they’re gone