Lecture 8 community ecology

Question 1

What is preadation/carnivory?

Answer 1

Prey is killed usually
predator is larger than prey
Multiple preys per preadator

Question 2

What is grazing/ herbivory?

Answer 2

Plants being eaten, preadation on plants

Question 3

What is parasitism/disease?

Answer 3

1. Host may or may not survive
2. Host generally larger than parasite
3. Multiple parasites per host

Question 4

What are brood parasites?

Answer 4

Birds that lay eggs in other bird’s next in order to save parental costs. It also involves brood mimicry. Like warbler and cuckoo

Question 5

What behaviour does Lotka-Volterra model tends to look like?

Answer 5

Cyclic (population size on y) and time on x

Question 6

Why is Lotka-voltera population graph cyclic?

Answer 6

Because if they are more preadtors they tend to eat more prey, which declines prey population, which also declines predators population and then as prey increase, predators also increase.

Question 7

What did Huffakar’s prey and predator model show?

Answer 7

Number of prey on y, number of prdators on x, six-spotted mites were prey while predator mite was the predator.

Question 8

What is the most common lab results with predator and prey inteactions in labs?

Answer 8

predator eats all the prey and the prey goes extinct. Then the predator starves and then goes extinct. (they cannot co-exist)

Question 9

Why is lotka-voltera model for predator and prey not usual?

Answer 9

• in real life, predator eats many species of prey, so they do not run out of food.

-Other factors are not included in lotka-voltera model, as hares might go extict because of heavy browsing

-Social stresses in over crowded population

most natural cycles have complex causes

Question 10

Why is measeals outbreak cyclic?

Answer 10

Not because of lotka-voltera model for predator and prey

-Because humans can get immunity, they tend to have lower rates

-but when babies are born they are not having immunity which causes outbreak.

Question 11

What does coevolution mean?

Answer 11

Species might reciprocally adapt to each other

Question 12

What is Red Queen Hypothesis?

Answer 12

It describes antagonistic coevolution between predator and prey, as the prey adapts, the predator also adapts. Fundamentally, doesn’t change the number of predators and prey.

Question 13

What is an example of Red Queen hypothesis?

Answer 13

Gartner snake and rough skin newts

Question 14

What is a life dinner principle?

Answer 14

Prey evolves faster than the predator. (like fox can reproduce after hunting a rabbit, while rabbit cannot)

Question 15

What are inducible defences?

Answer 15

like immune system, plants secondary chemicals, prey morphology, and behaviour and

Question 16

What happened when john Paine removed the predator star fish?

Answer 16

Musscles out grew its number and eradicated algae etc.

Question 17

What is enemy release hypothesis?

Answer 17

Invader species leave their predators in their native range, hence they out grow in this new range.

Question 18

What is a direct life cycle?

Answer 18

Parasites having a single host cycle

Question 19

What is a complex life cycle?

Answer 19

Parasites that require two or more life cycles are said to have complex life cycles.

Question 20

Who are reservoirs?

Answer 20

The species in which the pathogen initially was hosted in

Question 21

What is dilution effect?

Answer 21

For the diseases that affect many hosts, the host diversity can reduce the risk to human population

Question 22

What is amplification effect?

Answer 22

More host or vector species can support larger population of disease carrying organism increasing the risk to human or animals.

Question 23

Why are there more species in Warmer region?

Answer 23

-it had more time, then poles as poles were under ice from a long time

-Maybe climate