Summary
Graphs of the proportion of a cohort surviving by age, classified as type I, II or III.
In depth
Type I (humans, large mammals) shows low early mortality and high late mortality; type II (some birds and lizards) shows constant mortality; type III (oysters, many fish and plants) shows high early mortality.
Life tables supply the data.
Curves plotted on log scale: type I is convex, II straight, III concave. Real species may combine types at different life stages.
Example: trees produce many seeds but few reach maturity (type III).
Frequently asked questions
What is Survivorship Curves?
Graphs of the proportion of a cohort surviving by age, classified as type I, II or III.
Which area of biology covers Survivorship Curves, and how advanced is it?
Survivorship Curves is one of the 54 topics in Ecology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include r and K Strategies, Ecological Succession, Niche Partitioning.
Can you give an example of Survivorship Curves?
A sea turtle lays many eggs but few hatchlings survive to adulthood.
What should I learn before Survivorship Curves?
Work through the Beginner topics in Ecology first, such as Ecology, Ecosystem, Biotic and Abiotic Factors, then return to Survivorship Curves. Intermediate topics assume the Beginner vocabulary.
What topics are related to Survivorship Curves?
The closest topics to Survivorship Curves are r and K Strategies, Ecological Succession, Niche Partitioning, Competition. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Survivorship Curves?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Survivorship Curves. To practise the whole of Ecology, use the Ecology quiz.
How is Survivorship Curves different from r and K Strategies?
Survivorship Curves: Graphs of the proportion of a cohort surviving by age, classified as type I, II or III. r and K Strategies: r-strategists reproduce quickly with many offspring; K-strategists have few offspring and invest heavily in each. Read both side by side and note what each one explains.
How should I study Survivorship Curves step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with r and K Strategies and explain the difference aloud. Finally, take the Ecology quiz and come back to this page for any question you miss.