Daily life cycle to study reproduction schedules

Version 1 -- May 2017


The DAY program is an individual-based demographic model to study the risk of extinction associated with the reproduction schedule, represented by the time distribution of reproductive events: mean and standard deviation of the date of reproduction (Massot & al. 2017).

The model takes as input an annual age-classified life cycle (Caswell 2001) that is run on a one day time step. Two types of resource are available, constant or cyclic. From a set of population trajectories, the probability of extinction is estimated (Monte Carlo simulation).

The program runs under Windows.



After expanding the self-extracting archive autoday.exe, the DAY directory contains:

  • DAY program: day.exe
  • runtime library: qtintf.dll
  • reference manual: dayref.pdf
  • input data files (short and long life cycle): in_short.txt, in_long.txt
  • source files (Pascal programming language/Borland Delphi 6): source/*.pas, source/*.xfm

Running the program

The DAY program is easy to use. See the reference manual dayref.pdf.


Caswell H. 2001. Matrix Population Models: Construction, Analysis, and Interpretation. 2nd edition, Sinauer, Sunderland, Massachussets, USA.

Legendre S, J Clobert, AP Møller & G Sorci. 1999. Demographic stochasticity and the social mating system in the process of extinction of small populations: The case of passerines introduced to New Zealand. American Naturalist 153:449-463.

Massot M, S Legendre, P Frédérici & J Clobert. 2017. Climate warming: a loss of variation in populations can correlate with reproductive shifts.


Manuel Massot



Stéphane Legendre

Team of Eco-Evolutionary Mathematics

Ecole normale supérieure

46 rue d'Ulm

75005 Paris


Web site of Stéphane Legendre

Mail to Stéphane Legendre