moult (version 2.3.1)

ms2pfmg: 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 = "")

Value

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

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.

Author

Bo T. Bonnevie, Birgit Erni

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).

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 = ",")