Week 2 Questions

Question 1

Define: Population, Deme, Subpopulation, Metapopulation

Answer 1

population: A collection of organisms in the same species that interbreed

deme: Individuals of the same species that have a high likelihood of interbreeding

subpopulation: or a portion of a population in a specific geographic location or as delineated by nonbiological criteria

metapopulation: when a species whose range is composed of more or less geographically isolated patches, interconnected through patterns of gene flow, extinction, and recolonization

Question 2

population viability

Answer 2

likelihood of persistence of well-distributed population > 100 years

Question 3

dispersal

Answer 3

one-way movement, typically of young away from natal area

Question 4

Migration

Answer 4

a seasonal, cyclic movement typically across latitudes or elevations:
a. to track resources or
b. to escape harsh conditions changed by season

Question 5

home range

Answer 5

movement throughout a known space over a day/week/month to locate resources

Question 6

functional response

Answer 6

refers to changes in the behaviour of organisms

Question 7

source populations

sink populations

Answer 7

Source: populations of stable reproductive populations

Sink: habitats predominated by subdominant individuals and young of the year

Question 8

ecological traps

Answer 8

poor-quality habitat appears better than it is

Question 9

native species

non-native species

Answer 9

native: a species that is located in its presumed area of evolutionary origin and nonhuman-aided dispersal,

non-native species: (of a person, plant, or animal) not indigenous or native to a particular place

Question 10

Introducing’ wildlife

re-introducing wildlife

‘augmenting’ wildlife

Answer 10

Introducing’ wildlife: Species or genotypes not known to have existed there previously are established at a site. Species may or may not be native to a broader geographic area

re-introducing wildlife: Reestablishment of species or genotypes historically present at the project site but was extirpated.

‘augmenting’ wildlife: Individuals of a species are added to a site where the species occurs presently—also called restocking

Question 11

resident wildlife

translocated wildlife

Answer 11

resident wildlife: Species, populations, or genotypes native to a local site. These can be extracted from a local site for onsite restoration or augmentation

translocated wildlife: Genotypes are collected offsite for planting or release at a project site within the species’ natural range.

Question 12

genetic drift

Answer 12

the change in frequency of an existing gene variant in the population due to random chance

Question 13

hard release

soft release

Answer 13

hard release: animals are released into the wild without any conditioning at the release site

soft release: captured animals are held in captivity for an extended period

Question 14

minimum viable population

Answer 14

smallest size population (typically measured in absolute number of organisms rather than density or distribution of organisms) that can sustain itself over time

Question 15

numerical response

Answer 15

numerical response: refers to absolute changes in the abundance of individuals through changes in recruitment.

Question 16

Explain the concept of metapopulation. How does it relate specifically to restoring wildlife populations (factoring in dispersal ability)?

Answer 16

• when a species whose range is composed of more or less geographically isolated patches, interconnected through patterns of gene flow, extinction, and recolonization
• occur when environmental conditions or species characteristics retard the complete interchange of reproductive individuals
• there is greater demographic and reproductive interaction among individuals within, rather than among, subpopulations
• Identifying formerly occupied locations is a first step in prioritizing restoration efforts, need to identify:
• the metapopulation structure, and
• estimate of the abundance of individuals within each subpopulation,
• one goal - identify the metapopulation structure and then locate restoration sites to enhance this structure

Question 17

50-500 rule, and 10-50 generation rule

Answer 17

50–500 rule:
- populations of at least 50 breeding individuals are needed for short-term viability (factoring in environmental and demographic variability) and
- 500 individuals are needed for long-term viability (genetics)

10-50 rule:
- populations persist for 10 generations for environmental / demographic variability (population demography/dynamics*), or
- 50 generations for enhancing genetic variability

Question 18

Why is density a misleading indicator of habitat quality?

Answer 18

Does not provide information on:
- Reproduction, survival, dispersal rates, etc

Question 19

How does varying habitat quality affect metapopulation structure?

Answer 19

Because of the metapopulation structure, not all suitable habitats will be occupied at any one time:
o thus, unoccupied habitats must be monitored and conserved for many years,
o monitoring needs an adequate sample size to avoid concluding ‘absence,’
o this can be avoided with adequate sample size and monitoring duration,
o designing a restoration plan depends upon the size and fragility of the population and its habitats, and on project objectives,
o thus, identifying the structure of the population(s) of interest is critical if a restoration project is to be successful.

Question 20

How does the distribution pattern influence the approach to restoration?

Answer 20

• Many species have a bull’s-eye distribution:
• the greatest areas of abundance are toward the middle of their overall ranges and peripheral portions of the range in marginal conditions

Question 21

How does an understanding of dispersal influence restoration planning?

Answer 21

• provides information on where to prioritize the restoration
• e.g., breeding locations and natal areas

Question 22

How does an understanding of migration influence restoration planning?

Answer 22

• animals need food, water, cover, and space, and some animals will travel significant distances to obtain these resources.

Question 23

How does an understanding of home range influence restoration planning?

Answer 23

• detailed information on what animals use must be gathered to specify the vegetation and special habitat features needed
• Temporal aspect

Question 24

Why is knowing whether your measured population response is a ‘functional’ or ‘numerical’ response
essential?

Question 25

Explain the source-sink dynamics of populations and their impact on restorations

Answer 25

• Individuals in sink habitats are maintained by continuous immigration from source habitats.
• the metapopulation dynamic reflects frequent movements due to changing source-sink conditions among the individual populations.

Question 26

Describe how exotic species can impact restoration activities

Answer 26

• Exotics can quickly negate efforts to enhance native species following restoration
• sometimes native species rely on exotics….

Question 27

Why would you initiate ‘conservation breeding? (3 goals)

Answer 27

• to provide demographic and genetic support for wild populations,
• to establish sources for founding new populations in the wild,
• to prevent species extinction with no immediate chance of survival in the wild.

Question 28

What are the main concerns about captive breeding and restoring rare populations (3). Include concerns around genetic bottlenecks

Answer 28

1) Captive breeding is expensive, and translocation is problematic
2) the captive breeding program can induce additional mortality in the already-rare species, BC’s spotted owl
3) it is complex

Genetic bottlenecks:
- genetic manipulation could be required to restore/maintain evolutionary potential
- captive breeding can lead to loss of genetic variation through random drift

Question 29

What are the five key considerations to consider before augmenting a population?

Answer 29

1) are there two lines of evidence (e.g., genetic, demographic, and behavioural) that support the hypothesis that a severe population bottleneck has occurred?

2) would adding additional animals degrade resource conditions, driving the wild animals to a more rapid extinction?

3) was the population bottleneck due to a disease outbreak (or other specific and known occurrence), and can the source of the problem be eliminated?
4) are there habitat patches nearby to establish a larger population (or metapopulation) rather than a single, isolated population?
5) how should the sex and age composition of an augmentation be structured?

Question 30

13. Why is genetic variability in a population good?

How does conservation breeding compromise this variability?

Answer 30

• genetic variation largely determines the ability of populations to persist through changing environments
• captive breeding selection can eliminate alleles that are maladaptive (faulty adaptations) in the captive situation yet important for survival in the wild,
• random genetic drift can cause the cumulative loss of both adaptive and maladaptive alleles

Question 31

How does metapopulation structure enhance genetic variability?

Answer 31

Increasesit
- retain greater gene diversity (expected heterozygosity)
- greater allelic diversity than would a single, large (panmictic1) population

Question 32

Successful reintroduction: characteristics of the source population (3)

Answer 32

i. they may come from a captive population or an existing wild population

ii. given that mortality is high among reintroduced animals
- remove individuals only if the source population is not compromise
- only animals descending from the most prolific lineages

iii. the source population should have high genetic diversity, genetic similarity, and environmental similarity compared to the new population

Question 33

Successful reintroduction: b. evaluation of the reintroduction site (2)

Answer 33

• reintroduction programs must use high-quality habitat
• you must identify critical factors and their status in the release location

Question 34

Successful reintroduction: size of the reintroduction population

Answer 34

• For native game species, 20–40 founding animals have been sufficient for success.
• Some recommended that at least 30–50 individuals be released if possible.

Question 35

The success of any restoration program—rests fundamentally on

Answer 35

the habitat condition and niche of the species in question.

Question 36

What is the primary cause of failure in reintroductions?

Answer 36

Mortality due to predation is a primary cause of failure in reintroductions