Population Dynamics

Question

At the beginning of a year, there were 1923 painted turtles in a population. Over the year, 343 painted turtles were born, 176 died, 72 immigrated from other areas, and 12 emigrated.

(a) Determine the percentage population change of the painted turtle population.

(b) Do you think this information is enough to determine whether or not the growth rate of the population is a cause for concern? Explain your reasoning.

(c) While an accurate count of the turtle population is essential, what other data are important for developing a good conservation plan?

Answer 1

Initial Total Population: 1,923

Born: 343

Died: 176

Immigrate: 72

Emigrate: 12

1. Percent population change?
2. Growth rate? Concerning?
3. Other data to consider for a conservation plan?

Birth and Immigration are factors that contribute to the increase of a population.

Death and Emigration are factors that contribute to the decrease of a population.

(Birth + Immigration) - (Death + Emigration)

(343 + 72) - (176 + 12) = 415 - 188 = 227 painted turtles/year

Our outcome is positive 227; this tells us that the population increased by 227 from 1,923 to 2,150 painted turtles.

Population Percent Change:

(2150 - 1923)/1923 x 100 = 12%

Growth rate could be concerning IF SUSTAINED; that is, if growth continues to be the pattern year after year with no ebbing; the population will eventually crash due to exceeding the carrying capacity - but not immediately.

Every ecosystem requires balance. We understand the implications of uncontrolled growth. The conservation project should consider the natural predator of the turtle, along with the predator of the predator, etc. Shared resources? Shared niches? Each organismal population within the system should be kept in check. What would be the ideal keystone species for the environment? Keystone species are pivotal in maintaining balance among populations within an ecosystem.