Swirling a Vortex of Numbers to see animal populations’ futures

David Thompson (Bayard Middle School) & Diana Cheng (Towson University)http://tinyurl.com/p673fr7

Common Core State Standards for Mathematical Practice

• Modeling with Mathematics: how the biological phenomenon of population change can be modeled graphically – Experiment which mimics species’ changes in

population– Hypothesize & test ways to increase the population by

changing relevant parameters • Using appropriate tools strategically: Computer software

& spreadsheets, graphing calculators

Total # of Species & Threatened Species

Source: IUCN Red List

Quantities considered for classifications

% population reduction in 10 years Mature

population size

Reduction in geographic range

Tiger: Endangered since 1986

IUCN Red List Categories (2001)

Criteria for Threatened Levels(IUCN, 2001)

Table 1: IUCN Classifications

Examine Table 1 and answer the following questions regarding classifications of species’ threatened levels:• a. An animal’s population table is presented below. How

should this species be classified?Year Population size2000 10002010 700

• b. Suppose an animal’s population is 750 mature individuals and there is a 50% population reduction over a 10 year period. How would this species be classified?

• c. Provide a scenario in which an animal’s population is increasing, yet the species is still classified as endangered (EN).

A Technology-Enhanced Experiment

Vortex 10 software– Developed by the IUCN

Conservation Breeding Specialist Group & the Chicago Zoological Society

– Provided at no cost– http://vortex10.org/

Vortex10.aspx

• Some parameters:– Initial population size– Carrying capacity– % of adult females /

males breeding– Mortality rates– # of offspring per female

Small Group Workdthomp9@students.towson.edu

• Exploration A– A1 & A2– A3 & A4

• Exploration B– B1 & B2– B3 & B4