College of Du Page Evolution and Ecology Offspring Worksheet

Q 1. After you graduate from UIC, you get a great job as a conservation biologist for the state of Illinois. Your first project is to develop a conservation management plan for Bobolinks (Dolichonyx oryzivorus), a threatened bird species in Illinois. You decide to monitor the population at the Bobolink Meadow Land and Water Reserve in Tinley Park. You visit the reserve every year during the Bobolink breeding season and capture adult Bobolinks and mark them using colored metal leg bands. You return one month later and capture the Bobolinks again. You obtain the data in Table 1.

Homework 3 Table 1.docx

Homework 3 Table 1.pdf

Based on your results, estimate the number of individuals (Nx) in the population for each year (complete last column of the table). Show your work for the first two rows.

Based on your findings, what findings and recommendations would you include in your report on the conservation status of the Bobolink?

Q2 (5 POINTS)

You enjoyed working with the Bobolink so much that you decide to return to UIC to study Bobolinks for your PhD dissertation. For your doctoral research you follow a cohort of Bobolinks through their lives. Each summer, before Bobolinks migrate to South America to overwinter, you collect life history information. During the first breeding season, you find 86 nesting pairs of Bobolinks and, before their nestlings fledge, you band them. You return every year, capture the banded Bobolinks, and determine how many have survived. Based on this, complete Table 2.

Homework 3 Table 2.docx

Homework 3 Table 2.pdf

Q3 (5 POINTS)

What type of survivorship curve does this population have? Include a graph of lx vs. age (remember to graph lx on a log scale) to answer this question. Explain what this tells us about the life history of these birds. What would you recommend to conservation managers to help increase the population size of Bobolinks in the future? (Answer in 2-3 complete sentences.)

Q4 (5 POINTS)

The Bobolink Foundation is conducting a captive breeding program of Bobolinks to supplement the wild population. They share their demographic data, and you determine that, in the captive population of 63 Bobolinks, the females produce an average of 22 surviving chicks per year. On average, 19 Bobolinks in the captive population die each year. Given unlimited space and resources, how many Bobolinks would be in your captive population in 5 years? In 10 years? In 20 years? Show all your work.

Q5 (5 POINTS)

Briefly describe Bobolinks, including some information on about topics we’ve learned about in class (eg. range, mating system, life history). What is their conservation status? State a fact that you find interesting about Bobolinks.

type answers out and please use excel for graphs and fill out tables