Produce cumulative histograms with error bars, then fit a few common relevant distributions using fitdistr in R. The one with the lowest AIC is most suitable :)

That seems pretty slick. Have you seen that method done in other studies? Thanks for the suggestion!

Are you programing in R? I may help ya if it is the case...

Hello Jorge- yes I am working in R!

I´d rather start creating or defining a logistic function:

LogGrowth = function(Day, A, Ti, K){ (A)/(1 + exp((Ti - Day)*K)) }

hence ya would calculate the derivative of the logistic growth such as:

LogGrowthDeriv = deriv(body(LogGrowth)[[2]], namevec = c("A", "Ti", "K"), function.arg= LogGrowth)

Now.......

# Create a data frame with the weight and time (Age old)

datamydata

Did it work for you? Kara G. Snow

I suggest you need to weigh a few chicks daily or every couple of days to find out the shape of the curve. In starlings I worked on, they grew for 12 days and levelled off until they flew at 24days. Other birds get bigger than the adults and reduce weight before leaving the nest. This might not show in 3 point graphs.