# Function: ageAtFirstReproduction()

[**lifecycle-kit**](https://jonbogaty.com/lifecycle-kit/api/readme/index.md)

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[lifecycle-kit](https://jonbogaty.com/lifecycle-kit/api/readme/index.md) / [bio-laws](https://jonbogaty.com/lifecycle-kit/api/bio-laws/readme/index.md) / ageAtFirstReproduction


# Function: ageAtFirstReproduction() {#function-ageatfirstreproduction}


> **ageAtFirstReproduction**(`maxLifespan`): `number`

Defined in: [bio-laws/lifeHistory.ts:87](https://github.com/jbcom/lifecycle-kit/blob/074e4e7b8038d3e2de9eb44c4b5b5aee0ef02b48/src/bio-laws/lifeHistory.ts#L87)

Age at first reproduction, as a fraction of maximum lifespan.

Source: Charnov & Ernest (2006), as above.

Invariant across an enormous range of body sizes: organisms begin
reproducing at roughly a quarter of their potential lifespan.


## Parameters {#parameters}



### maxLifespan {#maxlifespan}


`number`


## Returns {#returns}


`number`