what is the survival of adélie penguins due to climate change: a study on population dynamics

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)

– Size range from centimeters to millions of square kilometers

Population Dynamics An area of population ecology concerned with

the factors influencing the expansion, decline, or maintenance of populations (Molles 2010, p. 222)

Why study population dynamics? – Saving endangered species – Controlling invasive species – Maintaining important populations– Growth of human population

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 at the 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

Static (vertical)

Data Collection for Life Table

Age (x) Nx Bx

0 16 02-4 8 05-7 5 28-10 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 11 186 02 58 6903 34 4654 22 3145 12 2016 5 877 2 358 0 0

Total

Age (x) Nx Bx lx mx lxmx xlxmx

0 1000 0 1 0 0 01 186 0 0.186 0 0 02 58 690 0.058 11.9 0.69 1.383 34 465 0.034 13.68 0.47 1.394 22 314 0.022 14.27 0.31 1.265 12 201 0.012 16.75 0.20 1.006 5 87 0.005 17.4 0.09 0.527 2 35 0.002 17.5 0.04 0.258 0 0 0 0 0 0

Total 1.79 5.80R0 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