56.2 Demography

• By the mid-19th century, annual plants produced more seeds than trees, which had been hunted and trapped to near extinction.
• A lot of energy is needed for maintenance.
• When the environment becomes stressed, annuals run the risk of their seeds being recovered in many areas and growing to what some considered to be not germinating.
• They need to rely on some seeds to be a nuisance.
• Legislation in Newfoundland supports germinating after environmental stress has ended.

• mandibles from 1964 to 1971 were provided by trappers.

• Only females produce offspring, so give and differentiate among type I, II, and III survivorship curves.
• The age examples of organisms that exhibit curves are included in the table.

• In this section, we will look at how individuals are categorized in a population.
• Ecologists can use survivorship curves for two reasons.
• There is a specific fertility data that can be used to predict population sizes.

• The information about the survival patterns of different species is lost if an age class begins with 100 individuals and 50 are lost.

• 50% of the individuals have been lost and the rates of change have not changed in absolute numbers.
• The use of a log scale makes it easier to plot a wide range of popula ent, even though the absolute numbers are different.

• The slope of the curve allows ecologists to compare populations that are different in size.
• If compared with another curve.

Which type of curve would you expect to see decline through time?

• Most individuals are lost later in life, as an example, once they find a suitable rock face on which to attach them they become older and more prone to sickness and predators.
• Organisms that lay many eggs or relatively few offspring but invest a lot of time and resources in raising their release hundreds of seeds fit the type III survivorship curve.

• Many large mammals, including humans, have type I curves.

• There is a type III curve at the other end of the scale.
• Many birds, small mammals, reptiles, and some annual plants have type II survivorship curves.
• The organisms that avoided early death are flattened out.
• There is a survivorship curve in the North American beaver population.

• Most of the juvenile are aware that these are generalized curves and that few die or are eaten, but a few reach a favorable habitat and thrive.
• Populations fit them exactly.

• Murie collected sheep skulls to determine the sheep's age in the 1930s.

• The way to increase the number of sheep was by collecting 608 skulls.
• Ameri parison was enlisted by the Park Service because meaningful data on Deevey was not available.
• Deevey used the data to create a can Biologist to determine if the wolves killed the survivorship curve.
• There is enough sheep to justify controlling the wolf population.

• The wolf population is harmful to reproductively active adults in the mountain sheep population.

• The park was formerly known as Mt.
• There is a wolf population in McKinley National Park.

• Only skulls with horns are found here.

• Annual growth rings are used to estimate an animal's age.

• The wolf population is harmful to reproductively active adults in the mountain sheep population.

• The park was formerly known as Mt.
• There is a wolf population in McKinley National Park.

• Only skulls with horns are found here.

• Annual growth rings are used to estimate an animal's age.

• Reducing the wolf population would not increase sheep survival.

• As they aged, the number of sheep declined rapidly.

How did Murie's data and Deevey's analysis affect the decision of the Park Service regarding the control of the wolf because the reproductively active adults were not being taken?

• The Park Service ended its wolf-control program.

• We have focused on survivorship so far.

• Table 56.1 shows a common trend in mammals.