Deck 11: Competition and Coexistence

Question 1

Invasive Grey squirrels are outcompeting red squirrels in Britain because...

A) they spread disease to red squirrels
B) they are more efficient at exploiting acorns.
C) they pilfer red squirrels acorn caches.
D) there is extensive habitat loss.
E) they physically intimidate red squirrels.

Answer 1

they pilfer red squirrels acorn caches.

Question 2

Parasites of one species of fly which makes galls on the seaside plant sea-oxeye daisy, can spill over and reduce the densities of galls on a neighboring plant, Jesuit's bark. This is an example of:

A) apparent competition
B) competition
C) associational susceptibility
D) mutualism
E) commensalism

Answer 2

associational susceptibility

Question 3

In competition experiments between the flour beetles T. castaneum , T. confusum and T. castaneum won mostly in_______, ________conditions.

A) Hot, dry
B) Hot, wet
C) Cold, dry
D) Cold, wet

Answer 3

Hot, wet

Question 4

Park's experiments showed the results of competition could vary as a function of

A) Temperature and salinity
B) Moisture and pH
C) Temperature and mutualists
D) Temperature, moisture and parasites
E) Temperature, moisture, parasites and predators

Question 5

Chthamalus stellatus and Semibalanus balanoides do not coexist in the same tidal zones because

A) S. balanoides outcompetes C. stellatus in the lower tidal zone
B) C. stellatus outcompetes S. balanoides in the lower tidal zone
C) C. stellatus outcompetes S. balanoides in the upper tidal zone
D) S. balanoides outcompetes C. stellatus in the upper tidal zone
E) The two species require different resources

Question 6

Two species of lizards, the canyon lizard, Sceloporus merriarni, and the tree lizard, Urosaurus ornatus both hunt for insect prey on rock surfaces. In 1976, an experimenter established removal plots, where one species of lizard was removed. Here are the resultant densities of lizards: Urosaurus with Sceloporus 55, Urosaurus alone 80, Sceloporus with Urosaurus 130, Sceloporus alone 129. What can you conclude?

A) There is no interspecific competition.
B) Intraspecific competition is not important.
C) Sceloporus is a better competitor than Urosaurus.
D) Urosaurus is a better competitor than Sceloporus.

Question 7

A group of species that feed on the same resource, in the same way, is known as a

A) Group
B) Guild
C) Fundamental niche
D) Fundamental group
E) Fundamental guild

Question 8

On Anticosti island, black bears have been outcompeted by

A) Elk
B) White tailed deer
C) Moose
D) Grizzly bears
E) Dingoes

Question 9

What organism appeared in the Mobile area of the U.S. in 1918 and has since spread throughout the U.S. South?

A) Thylacine
B) Goats
C) Garlic mustard
D) Brazilian pepper
E) Fire ants

Question 10

Which is NOT a recognized hypothesis to account for the strong competitive ability of invasives?

A) Enemy release
B) Superior competitor
C) Lack of environmental constraints
D) Propagule pressure
E) Climate pre-adaptation

Question 11

In a plant competition experiment between two closely related species Desmodium glutinosum and D. nudiflorum, average growth of individuals in given in parentheses: Desmodium glutinosum grown alone (130 cm), grown within in 10 cm of large D. glutinosum individuals (25 cm), or within 10 cm of large D.nudiflorum individuals (45 cm). Desmodium nudiflorum grown alone (25 cm), within in 10 cm of large D. nudiflorum (15 cm) or within 10 cm of D. glutinosum (5 cm). What can you conclude?

A) There is no competition.
B) The growth of D. nudiflorum is depressed more by interspecific competition than by intraspecific competition.
C) The growth of D. nudiflorum is depressed more by intraspecific competition than by interspecific competition.
D) The growth of D. glutinosum is depressed more by interspecific competition than by intraspecific competition.
E) Competition between species is equal.

Question 12

If K₂>K₁/ $\alpha$ 1F10 and K₂ / $\beta$ > K₁, then

A) Species 2 is eliminated
B) Species 1 is eliminated
C) Either species 1 or species 2 is eliminated depending on starting conditions
D) Both species coexist

Question 13

In competition between P. caudatum and P. bursaria, neither species goes extinct. This is because they don't utilize the same resource. This conclusion is generalized as the

A) Coexistence theory
B) Competitive exclusion theory
C) Character displacement theory
D) Fundamental niche hypothesis
E) Gause hypothesis

Question 14

Using Tilman's R* competition models and given the R* values for the species of diatoms listed below, which species is likely to lose all possible pairs of competitive interactions?

A) Synedra, R* = 1.33
B) Asterionella, R* = 0.80
C) Cyclotella, R* = 0.72
D) Tabellaria, R* =9.7
E) Impossible to determine from the information provided.

Question 15

Richard Southwood and others suggested species cannot coexist if d/w is

A) <1
B) >1
C) >1<3
D) >3<1
E) >3

Question 16

The tendency for two species to diverge in size of body parts associated with feeding is called

A) Competitive displacement
B) Resource partitioning
C) Divergent mutualism
D) Character displacement
E) Interspecific competition

Question 17

Resource partitioning ___________ interspecific competition.

A) Eliminates
B) Reduces
C) Increases
D) Delays

Question 18

Allelopathy involves interference competition.

Question 19

Theoretically, for one limiting resource, the species with the highest R* should displace all the others from the habitat.

Question 20

In competition between the freshwater diatoms Asterionella and Synedra, Synedra reduces the silicate concentration to lower levels than Asterionella and thus outcompetes it.

Question 21

Proportional similarity values of <0.70 have been taken to indicate possible coexistence.

Question 22

Tilman's R* models predict the outcome of competition based on resource use; whereas Lotka-Volterra models do not.