What is the Survival of Adélie Penguins due to Climate

Change: A Study on Population Dynamics

By: Jessica Caton

Introduction to Population Ecology • What is a population?

– A group of individuals of a single species inhabiting a specific area (Molles 2010, p. 202)

• Why study populations? – Saving endangered species – Controlling pest populations– Clues to understanding/controlling disease – Growth of human population

Population Dynamics

An area of population ecology concerned with the factors influencing the expansion, decline, or maintenance of populations (Molles 2010, p. 222)

Populations dynamics are important due to key to understanding: - decline of threatened/endangered species- control invasive species- maintain culturally/economically important populations

Antarctic Species of Interest:Adélie Penguin

(Pygoscelis adeliae) • Physical appearance:

– Medium-sized (2 feet tall), black and white – Angular head and tiny bill– White eyering – Longest feather on body is the tail

• Smallest penguin in Antarctica

• One of the pack ice Antarctic penguins

• Most numerous bird in Antarctica

Adélie Penguins and Climate Change

• One of the best studied birds

• Changing population of species: numbers dropped a third

• Sea-ice decline, Adélie penguin populations decline

• Evolution of environmental instability?

Life Tables

A table that uses age specific information to estimate important population dynamic traits on a population

Types of Life Tables

• Cohort Life Tables(horizontal)

• Static Life Tables(vertical)

After reviewing both concepts click HERE

Cohort Life Table Time

Cohort (horizontal)

A table based on individuals born (or beginning

life in some other way) at same time (Molles 2010, p. 230)

Static Life Table

•A life table constructed by recording the age at death of a large number of individuals•A snapshot of survival within a population during a short interval of time (Molles 2010, p. 231)

Time

Data Collection for Life Table

Age (x) Nx Bx

0 16 0

2-4 8 0

5-7 5 2

8-10 2 4

Age (x) Nx Bx

0 1000 0

1 186 0

2 58 690

3 34 465

4 22 314

5 12 201

6 5 87

7 2 35

8 0 0

Age (x) Nx Bx lx mx lxmx xlxmx

0 1000 0 1

1 186 0

2 58 690

3 34 465

4 22 314

5 12 201

6 5 87

7 2 35

8 0 0

Total

Age (x) Nx Bx lx mx lxmx xlxmx

0 1000 0 1 0 0 0

1 186 0 0.186 0 0 0

2 58 690 0.058 11.9 0.69 1.38

3 34 465 0.034 13.68 0.47 1.39

4 22 314 0.022 14.27 0.31 1.26

5 12 201 0.012 16.75 0.20 1.00

6 5 87 0.005 17.4 0.09 0.52

7 2 35 0.002 17.5 0.04 0.25

8 0 0 0 0 0 0

Total 1.79 5.80

R0 3.24

T

Variables

• X = Age• N = Population

size• B = Birth rate• l =

Survivorship• m = Average

offspring

• T= generation time

• r = per capita rate of increase

• R0 = Net reproductive rate

Calculations

Interpreting

• Age structure = NX

• Generation time = T (am I in your generation)

• Per capita rate of increase = r (-, 0, +)

• Net reproductive rate = R0 (0, <1, >1)

Survival and Mortality in a Population of Adélie Penguins

(Ainley & DeMaster 1980)

Survivorship Curve

• A graphical summary of patterns of survival in a population (Molles 2010, p. 231)

• Three types:– Type 1 = High mortality in

older individuals– Type 2 =Constant mortality rate– Type 3 =High mortality in juveniles

Type 1

Survivorship Curve Home

Type 2

Survivorship Curve Home

Type 3

Survivorship Curve Home