Survivorship curves: All 3 types and their important examples

Survivorship Curve survivorship curves
Survivorship curve 3 types
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Biologywala.com By: Sachin's Biology

What is the survivorship curve?

Survivorship curves are the graphic representation of Survival chances at different ages of individuals. based on numbers of survival in log scale at pre-reproductive, reproductive, and post-reproductive phase.

Survivorship curve Types
Survivorship curves Types

As shown in the above image there are three types of survivorship curves based on their survival strategies at different stages of life.

Type I:

Survivorship curve type 1
Survivorship curve type 1

This type of survivorship curve is shown by typically ‘K’ selected species. In the type, I curve the mortality rate at juvenile (newborn) is comparatively low as maximum deaths occur at the post-reproductive phase. Because they become older and more susceptible to diseases and predation. Organisms showing type 1 survivorship curves tend to produce less number progeny and invest high energy in parental care. High parental care and less number of progeny results in a low infant (newborn) mortality rate.

It is an excellent strategy to produce fewer numbers of progeny with high parental care to increase the survival rate of offspring under predation force. This survival strategy increases the likelihood of being alive. High generation time and late reproductive are the distinct characteristics of individuals with type I survivorship curves. Such individuals generally show a shallow slope at a young age and an abrupt increase in death at later stages of life. Hence finally it became the CONVEX curve.

Examples of survivorship curve 1:

1. Humans
2. Mammals
3. Drosophila.

Type II:

Survivorship curve Type 2
Survivorship curve type 2

Organisms with a type two survivorship curve show s moderate changes with nearly uniform death rates thought out their life. This type of curve is generally shown by organisms that live under continuous predator pressure. Individuals are lost mostly due to accidents and predation. The species with type II survivorship curve includes small mammals, many birds, and some annual plants as well. The individuals in this type of curve are not born as fit as type I nor as fragile as type III survivorship curve.

The numbers of progeny produced are moderate and not as large as the type III survivorship curve showing individuals.

Examples of survivorship curve 2:

Examples of Type II survivorship curve are butterfly ( important for CSIR NET EXAM), birds, mice, rabbits, and most of the holometabolous insects (in case if you don’t know: Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago or adult.)

Type III:

Survivorship curve type 3
Survivorship curve type 3

Organisms that invest high energy to produce a high number of offspring show a type III survivorship curve. These organisms produce a large number of progeny and display a minimal decline in fecundity (ability to produce an abundance of offspring )  with age if they survive up to reproductive age. In the type III survivorship curve,e the rate of loss of juveniles is high, which is shown by the early downfall of the survival curve. Survival becomes easy for the individual which avoids early deaths, hence at the end curve becomes flattened.

Generally, this type of survival strategy is used in harsh environmental conditions where the survival chances of newborns are less. To overcome this less survival chance organisms produce a high number of offspring so that even after many deaths in the initial (juvenile) phase sufficient number of offspring will survive.

Examples of survivorship curve 3:

Fish and Marine invertebrates use this pattern. Many insects and plants also fit the type III survivorship curve because they lay many eggs and released hundred of seeds respectively and most of this die. Other examples include sea turtles, oysters, fishes, and trees.

What is the survivorship curve?

Survivorship curve Types

Survivorship curves are the graphic representation of Survival chances at different ages of individuals. based on numbers of survival in log scale at pre-reproductive, reproductive, and post-reproductive phages.

What are the examples of survivorship curve 1

1. Humans
2. Mammals
3. Drosophila.

What are the examples of survivorship curve 2

Examples of Type II survivorship curve are butterfly ( important for CSIR NET EXAM), birds, mice, rabbits, and most of the holometabolous insects (in case if you don’t know: Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago or adult.)

What are the examples of survivorship curve 3

Fish and Marine invertebrates use this pattern. Many insects and plants also fit the type III survivorship curve because they lay many eggs and released hundred of seeds respectively and most of this die. Other examples include sea turtles, oysters, fishes, and trees.

What are the differences between Survivorship curve 1, 2 and 3 ?

Survivorship curves

There are several differences between Survivorship curve 1 , 2 and 3 all have mentioned in this table image !

If you are having a problem with the clarity of the image you can  download the same survivorship curve table from here :

Download Survivalship Curve Table Notes

That’s it for the Survivorship Curve article, see you in the next article.

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Sachin Chavan

Sachin Chavan is working as Ph. D. Scholar with CSIR NET JRF AIR 21, GATE, MH-SET Online content writer and founder of Sachin's Biology and biologywala.com.

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1 Response

  1. Shweta says:

    Easy to understand..
    Great job Sachin..

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