Movement and Metapopulations

Question 1

Three phases of movement…

Answer 1

Emigration, Transfer, Immigration

Question 2

What are four broad aspects of studying movement?

Answer 2

Why move, nature of the movement, environmental drivers of movement and evoloutionary consequences

Question 3

What are the two categories of dispersal?

Answer 3

Natal and Breeding

Question 4

Examples of migration patterns…

Answer 4

Resource Patterns - Monarch butterflies south overwinter then four generations migrating north, tracing milk weed
Mule deer and American Elk into high mountain areas in summers, maybe seasonal or food supply
NH terrestial birds move north in spring, breeding with abundant food supplies, then south to savannas when foods abundant after rainy season

Question 5

Seasonal Migrations

Answer 5

Most common, caused by external seasonal phenomenon, preceded by physiological canges like body fat

Question 6

Example of migratory conservation…

Answer 6

Alewife fish in freshwater as young, migrating to ocean, blocked by dammming
Managing discharge based on migration patterns.

Question 7

Example of abstract Active-Passive continuum…

Answer 7

Spiders climb to high place, release gossamer carrying them on winds

Question 8

Active-Passive continuum seed dispersal…

Answer 8

Passive, however moved by an agent, spikes on herb seeds increase passive carrying on animal coats, or resistance to digestion

Question 9

Mutalisitc dispersal…

Answer 9

Mites cling to beetles to traverse dung whilst elimintating eggs of flies

Question 10

Types of Dispersion…

Answer 10

Random
Regular
Aggregated

Question 11

What are the proximal causes of dispersion?

Answer 11

Evolotuionary triggers favoured by NS and consequences being individuals locations in habitats and interactions

Question 12

Patchiness

Answer 12

All ecosystems patchy, created abiotically or biotically, grazing or water/moneral depletion

Question 13

Ecological Grain

Answer 13

Describes the smallest scales at which an ecosystem can respond

Question 14

Example of ecological grain

Answer 14

Bird view a hickory-oak mixture as a fine grain if they indiscriminately predate, whilst an insect coarse grained if preferentially predating

Question 15

Turnover Dispersal

Answer 15

Local organism movement into a gap from occupied habitat surrounding it

Question 16

Why may aggregation dispersal occur?

Answer 16

Conglomerate to favourable habitat, selfishness to decrease predation

Question 17

Philopatry

Answer 17

Tendency to return to the site of birth for breeding

Question 18

Philopatry and aggregation dispersal…

Answer 18

High gene proportion and habitat familiarity

Question 19

What acts against aggregation?

Answer 19

Intensive competition or limitation of resources

Question 20

Inbreeding as an evolutionary driver of dispersal…

Answer 20

The closer born individuals are, the morel ikely they are related and the more inbed their offspring

Question 21

Outbreeding Depression

Answer 21

Dispersal where gene combinatiosn break up

Question 22

Polymorphic Dispersal example…

Answer 22

Some plants produce seeds for both local and wide-range, some performing self pollitnation whislt others germinate underground

Question 23

Example of sex related diserpsal…

Answer 23

Females more dispersive when males establish and defend territorites or males in polygynandrous as males defend access to groups to females

Question 24

Example of dispersal affecting population dynamics?

Answer 24

Resources such as seeds for birds can determine where the birds may inhabit:

Question 25

Dispersal considertion in conservation…

Answer 25

Flying squirrels in Finland due to habitat loss/fragmentation, being a highly dispersive species, with patches for breeding, so physical connectivity important.

Question 26

Implication for dispersal peturbation on invasion…

Answer 26

North America great lakes invaded by 170 alien species, derived from freight ships mostly and discharge of many containing plants and animals

Question 27

How may invasvieness be controlled?

Answer 27

Political enforcement of compulsory open ocean discharge or filtration systems

Question 28

Case study of invasion…

Answer 28

Zebra mussles have massive economic implications: depletion of food and O2 availability, clogging of water intake pipes in hydroelectric plants and water filtration system

Question 29

Metapopulations

Answer 29

These are dynamically determined by extinction of subpopulatiosn and colonisation rate of new ones by dispersal, thus the role of extinction and colonisation in dynamics

Question 30

Species Distribution Modelling

Answer 30

A form of model of relationship between environment and species, based on variety of envrionmental variables, allowing spatial predictions

Question 31

How is SDM performed?

Answer 31

Information collected on where species found, extrapolated against locations they are not, potential habtiatiability

Question 32

What might limit species colonisation?

Answer 32

Dispersal effectiveness, so information gathered on environmentally variables predicting survivability

Question 33

Levins Model

Answer 33

Describes temporal changes in regional abundance by extinction and colonisation of metapopulations

Question 34

Derive dp/dt = cp(1-p)-ep

Answer 34

e is local extinction rate of patches
c is colonisation rate of empty patches
(1-p) depicts empty patches prone to recolonisation

Question 35

What does dp/dt = cp(1-p)-ep say?

Answer 35

Recolonisation rate increases with (1-0) and with fraction of occupied patches that can provide colonisers, with extinction rate increasing with fraction of patches prone to extinction

Question 36

What are necessary features of a MP?

Answer 36

Chance of extinction/recolonisation of subpopulation, and independent dynamics of the subpopulations

Question 37

Example of MP dynamics?

Answer 37

Glenville fritillary butterfly inhabits dry meadows supporting one of its two larval hosts, fragmented 4,500 patches, covering only 1% of total area, split into 125 semi-independent networks