Rcapture (version 1.2-1)

BBS2001: Species Richness Data from the North American Breeding Bird Survey (BBS) in 2001

Description

This data set contains species richness data from the North American Breeding Bird Survey (BBS) in 2001. The number of capture occasions $t$ is 50.

Usage

data(BBS2001)

source

Dorazio, R. M. and Royle, A. J. (2003) Mixture models for estimating the size of a closed population when capture rates vary among individuals. Biometrics, 59, 351--364

Details

This data set is presented in Dorazio and Royle (2003). It comes from the North American Breeding Bird Survey (BBS). This survey includes more than 4000 39.4 km survey routes throughout North America. Along each survey route an observer stops at 50 equidistant locations and records the species identity and number of all birds heard or seen within a 3-minute period. The data in BBS2001 was collected along Route 123, in Maryland, in 2001. In this data set a capture occasion is in fact a location and the frequencies represent the number of species detected at $i$ locations out of the 50 locations on that route. The frequencies for $i=37,\ldots,50$ are null and do not appear in the data set.

Examples

data(BBS2001)
desc<-descriptive(BBS2001,dfreq=TRUE,dtype="nbcap",t=50)
plot(desc)
   # Note in this plot the convex shape typical of model Mh.

cp<-closedp.0(BBS2001,dfreq=TRUE,dtype="nbcap",t=50,t0=20)
cp
plot(cp)
   # The Gamma estimator has the smallest deviance and the all 
   # its residuals are small.
   
   # Let's calculate a profile confidence interval for the gamma 
   # estimator:
closedpCI.0(BBS2001,dfreq=TRUE,dtype="nbcap",t=50,t0=20,
            m="Mh",h="Gamma",theta=3.5)			

   # One can also calculate a profile confidence interval for Chao's 
   # lower bound:
closedpCI.0(BBS2001,dfreq=TRUE,dtype="nbcap",t=50,t0=20,
            m="Mh",h="Chao")