Fauna::ReproductionLogistic Class Reference

Reproduction model following Illius & O’Connor (2000) More...

#include <reproduction_models.h>

Public Member Functions
	ReproductionLogistic (BreedingSeason breeding_season, const double max_annual_increase, const double growth_rate, const double midpoint)
	Constructor. More...
double	get_offspring_density (const int day_of_year, const double body_condition) const
	Get the amount of offspring for one day in the year. More...

Private Attributes
const BreedingSeason	breeding_season
const double	max_annual_increase
double	growth_rate
double	midpoint

Detailed Description

Reproduction model following Illius & O’Connor (2000)

The formula is derived from the model by Illius & O’Connor (2000) [35]. Their variable names are used here:

• B_annual: offspring count per year for one mature female
• k: maximum annual offspring count of one female
• F: current fat mass
• F_max: maximum fat mass
• b and c are parameters controlling the effect of body condition (F/F_max) on the reproductive rate and are set in Illius and O’Connor (2000) to b=15 and c=0.3 (unfortunately without explanation). c is called the midpoint, and b is called the growth rate a generalized logistic function.
• 50% of adults will breed when F/F_max=0.3
• 95% will breed when F/F_max=0.5

The annual rate is then converted to a daily rate over the breeding season length:

• L: length of breeding season [days]

Note

This reproduction model principle also used by Pachzelt et al. (2013) [49] and Pachzelt et al. (2015) [50]

See also

Fauna::ReproductionModel

Hft::reproduction_model

Hft::reproduction_logistic

Todo:

How does I&O determine the month?

Constructor & Destructor Documentation

ReproductionLogistic()

ReproductionLogistic::ReproductionLogistic	(	BreedingSeason	breeding_season,
		const double	max_annual_increase,
		const double	growth_rate,
		const double	midpoint
	)

Constructor.

Parameters

max_annual_increase	Highest possible (i.e. under optimal nutrition) offspring count of one female on average. A value of 1.0 means, a female begets one child every year.
breeding_season	When parturition occurs.
growth_rate	Parameter b in the equation, defining the slope of the sigmoid curve.
midpoint	Parameter c in the equation, defining the turning point (threshold) of the sigmoid curve.

Exceptions

std::invalid_argument	If max_annual_increase is negative.
std::invalid_argument	If midpoint is not in interval (0,1).
std::invalid_argument	If growth_rate is <=0.

Member Function Documentation

get_offspring_density()

double ReproductionLogistic::get_offspring_density	(	const int	day_of_year,
		const double	body_condition
	)		const

Get the amount of offspring for one day in the year.

Parameters

day_of_year	Day of year (0=Jan 1st).
body_condition	Fat mass divided by potential maximum fat mass [kg/kg].

Returns

The average number of children a female gives birth to at given day.

Exceptions

std::invalid_argument

If day_of_year not in [0,364] or body_condition not in [0,1].

Member Data Documentation

breeding_season

const BreedingSeason Fauna::ReproductionLogistic::breeding_season

private

growth_rate

double Fauna::ReproductionLogistic::growth_rate

private

max_annual_increase

const double Fauna::ReproductionLogistic::max_annual_increase

private

midpoint

double Fauna::ReproductionLogistic::midpoint

private

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The documentation for this class was generated from the following files:

• /home/docs/checkouts/readthedocs.org/user_builds/modular-megafauna-model/checkouts/latest/src/Fauna/reproduction_models.h
• /home/docs/checkouts/readthedocs.org/user_builds/modular-megafauna-model/checkouts/latest/src/Fauna/reproduction_models.cpp