Bird Population Analysis: Calculating Adult Males
This problem requires calculating the number of adult males in a bird population based on the given sex ratio, reproductive success, and total population size.
Understanding the Given Data
- Initial adult sex ratio (Male:Female) = 3:2
- Eggs produced per female = 8
- Juveniles surviving per female = 4
- Total population at the end of the season = 1300 individuals
- Assumption: No deaths occurred.
Step-by-Step Calculation
Let M be the number of adult males and F be the number of adult females.
From the sex ratio, we know that M / F = 3 / 2. This implies M = (3/2) * F.
The total number of adults is A = M + F.
Substituting M: A = (3/2) * F + F = (5/2) * F. Therefore, F = (2/5) * A.
And M = (3/5) * A.
The total population (P) consists of adult males, adult females, and juveniles produced.
Number of juveniles produced = Number of females (F) × Juveniles surviving per female.
Number of juveniles = F × 4.
Total population P = M + F + (F × 4).
Since A = M + F, we can write:
P = A + (F × 4).
Substitute F = (2/5) * A:
1300 = A + ((2/5) * A × 4)
1300 = A + (8/5) * A
Combine the terms for A:
1300 = A * (1 + 8/5)
1300 = A * (5/5 + 8/5)
1300 = A * (13/5)
Solve for the total number of adults (A):
A = 1300 × (5/13)
A = 100 × 5
A = 500 adults.
Now, calculate the number of adult males (M) using the ratio:
M = (3/5) * A
M = (3/5) * 500
M = 3 × 100
M = 300 individuals.
Important Questions from Population characteristics
- Consider the following strains of an influenza virus and their basic reproduction numbers ($R_0$). Assuming that they are all equally virulent, which one of the following strains would be most concerning for a completely vulnerable population of humans?
- Which one of the following sets of characteristics is most likely to cause population extinction via demographic stochasticity?
- What is the relationship between effective population size ($N_e$) and total population size ($N$) of any naturally occurring eukaryotic population?
- The effective population size of a sexually reproducing, diploid, animal species will be highest when the sex ratio (number of reproducing males / number of reproducing females) is
- Which of the following plots describes the expected relationship between population size (y-axis) and generation time (x-axis) in vertebrates? Here, each data point represents a different vertebrate species and the generation time is defined as the average interval between two generations.
