Class Notes (836,201)
Canada (509,690)
BIOL 3542 (32)

Lec 7.doc

2 Pages
Unlock Document

Biological Sciences
BIOL 3542
Jason Leboe- Mcgowan

How Do Ecologists Study Populations? • Population consists of the individuals of a species within a given area • any given time, an individual organism occupies only one spot in space- particular age and size • members are distributed over space, differ in age and size • age distribution of individuals in a pop’n and the way they are spread over the environment describe its population structure • population density: number of individuals of a pop’n per unit of area • structure of a pop’n changes continually b/c of demographic events- births, deaths, immigration, emigration • study of birth death and movement rates that create population dynamics changes in pop’n structure and density) is known as demography • ecologists determine how many individuals are found in an area and where they are located • individuals change their locations by migrating or dispersing • investigators need to be able to recognize and track individual animals • field studies of animals pop’ns require tagging or marking individuals in some way • birds are marked by coloured bands on legs; butterflies coloured spots on wings; bees-numbered tags on bodies; mammals-tags or dye on fur; plants- tags on branch or nearby ground • microchips and other forms of electronic tagging are used on organism of all sizes • molecular markers used to determine movement of individuals over long distances • one way – analyze the chemical composition of feathers that the birds molt as they migrate south-can determine where they molted by evaluating hydrogen isotopes in feathers b/c there is a strong latitudinal gradient in stable hydrogen isotopes in precipitation • Most individuals molted their feathers close to the breeding ground POPULATION DENSITIES • Ecologists usually measure the densities of organism in terrestr
More Less

Related notes for BIOL 3542

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.