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Clutch size is an important value for estimating nest dates and determining the successfulness of a nest. NestWatch participants may forget to enter clutch size into the nest attempt's summary data. But clutch size information may be estimated from the data of individual nest visits. This function used available data from any entered nest visits to estimate maximum host egg count (clutch size).

Usage

nw.estclutchsize(data, output = NULL)

Arguments

data

dataframe; A dataframe containing merged NestWatch attempts and visits data.

output

character; An optional character vector to rename the resulting output.

Value

dataframe; A dataframe with an additional binary column Clutch.Size.Estimated where 1 denotes the clutch size was estimated by the function and 0 denotes the clutch size was provided by the participant.

Details

This function looks for data contained in several columns to estimate what the clutch size of the nest was. Because NestWatch participants do not necessarily visit each nest everyday or record all data fields on every visit the data needed to estimate clutch size may be spread over many columns. Depending on the data available, the certainty of the clutch size estimate may vary, or in some cases, may not be estimable. For instance, a successful nest with 4 eggs recorded on several checks and 4 fledged young observed would have high certainty that the clutch size was 4. However, if a nest was observed with 2 eggs on one check and a week later was found predated, the certainty of the clutch size is not known. In this case the clutch size would be estimated as 2 but may have been higher depending on the exact (unobserved) failure date.

Examples

# Example simplified NestWatch dataset:
data <- data.frame(Attempt.ID = c(1, 2, 3, 4, 5, 6),
                   Visit.ID = c(1, 2, 3, 4, 5, 6),
                   Clutch.Size = c(1, NA, NA, NA, NA, NA),
                   Host.Eggs.Count = c(1, 2,  NA, NA, NA, 3),
                   Young.Total = c(1, 2, 3, 3, 4, NA),
                   Live.Host.Young.Count = c(1, 1, 2, 3, 1, 1),
                   Unhatched.Eggs = c(0, 0, NA, NA, 1, 3),
                   Young.Fledged = c(1, 0, NA, NA, 1, 3),
                   Dead.Host.Young.Count = c(0, NA, NA, 1, 0,1))

# Estimate Clutch Sizes if NA
nw.estclutchsize(data = data, output = "out")

out$Clutch.Size   # clutch size values
#> [1] 1 2 3 4 5 6
out$Clutch.Size.Estimated   # binary indicator if clutch size is estimated (1) or not (0)
#> [1] 0 1 1 1 1 1