VGAM (version 1.1-8)

prinia: Yellow-bellied Prinia

Description

A data frame with yellow-bellied Prinia.

Usage

data(prinia)

Format

A data frame with 151 observations on the following 23 variables.

length

a numeric vector, the scaled wing length (zero mean and unit variance).

fat

a numeric vector, fat index; originally 1 (no fat) to 4 (very fat) but converted to 0 (no fat) versus 1 otherwise.

cap

a numeric vector, number of times the bird was captured or recaptured.

noncap

a numeric vector, number of times the bird was not captured.

y01, y02, y03, y04, y05, y06

a numeric vector of 0s and 1s; for noncapture and capture resp.

y07, y08, y09, y10, y11, y12

same as above.

y13, y14, y15, y16, y17, y18, y19

same as above.

Details

The yellow-bellied Prinia Prinia flaviventris is a common bird species located in Southeast Asia. A capture--recapture experiment was conducted at the Mai Po Nature Reserve in Hong Kong during 1991, where captured individuals had their wing lengths measured and fat index recorded. A total of 19 weekly capture occasions were considered, where 151 distinct birds were captured.

More generally, the prinias are a genus of small insectivorous birds, and are sometimes referred to as wren-warblers. They are a little-known group of the tropical and subtropical Old World, the roughly 30 species being divided fairly equally between Africa and Asia.

Examples

head(prinia)
summary(prinia)
rowSums(prinia[, c("cap", "noncap")])  # 19s

#  Fit a positive-binomial distribution (M.h) to the data:
fit1 <- vglm(cbind(cap, noncap) ~ length + fat, posbinomial, prinia)

#  Fit another positive-binomial distribution (M.h) to the data:
#  The response input is suitable for posbernoulli.*-type functions.
fit2 <- vglm(cbind(y01, y02, y03, y04, y05, y06, y07, y08, y09, y10,
                   y11, y12, y13, y14, y15, y16, y17, y18, y19) ~
             length + fat, posbernoulli.b(drop.b = FALSE ~ 0), prinia)