ms2pfmg {moult}

Convert moult scores to proportion of feather mass grown

Description

Convert moult scores obtained for single feathers into overall proportion of feather mass grown.

Usage

ms2pfmg(ms, fm, split = "")

Arguments

ms

vector of moult scores. Each moult score should be a character string of one individual's feather moult scores, each between 0 and 5, e.g. "555444000" if nine primaries are of interest. Half steps are allowed, in which case the separator between individual scores can be specified in split, e.g. "5 5 5 4.5 4 3.5 0.5 0 0", in which case split = " ".

fm

vector of relative feather mass, corresponding to each feather in ms.

split

character used to separate individual feather moult scores. Default is no space / separator between scores.

Details

ms will usually be a vector of 9 or 10 primary feather scores, but single feathers can be given, in which case fm is ignored. The method used here assumes that a moult score of 1 for any feather corresponds to 1/8th of the feather grown, 2 corresponds to 3/8th = 0.375, etc.. The proportion of feather mass grown is then a weighted sum over all feathers, with weights equal to the relative weight (compared to the total weight) of each feather (Underhill and Zucchini 1988).

Value

ms2pfmg returns a vector (same length as ms) of values between 0 and 1: proportion of total feather mass grown.

Author(s)

Bo T. Bonnevie, Birgit Erni

References

Underhill, L. G. and Zucchini, W. (1988) A model for avian primary moult. Ibis 130, 358–372.

See Also

predict.moult, moult

Examples

## relative primary feather mass of the 10 primary feathers 
## (as proportion of total feather mass) for Sanderlings
fm.sand <- c(0.0385, 0.0458, 0.0544, 0.0680, 0.0827, 0.1019,
             0.1199, 0.1417, 0.1604, 0.1867)   

ms2pfmg(3, 0.2)              # single feather
ms2pfmg(3, 1)
ms2pfmg("5555500000", fm.sand)

## all feathers weighted equally
ms2pfmg("54321", c(1,1,1,1,1))

## with half scores
ms2pfmg("5 4.5 3 2.5 1", c(1,1,1,1,1), split = " ")

## moult scores for more than 1 bird 
ms2pfmg(c("5,4.5,3,2.5,1", "5,3.5,3,2.5,2.5"), c(1,1,1,1,1), split = ",")