`panel4pt4.fn` <-
function(y=catbird.vec,nsites=50,J=11,Nmax=100){

# R code for obtaining MLEs under the Royle-Nichols model with
# quasi-binomial detection function (Panel 4.4)

lik<-function(parms){
  r<-expit(parms[1])
  lambda<-exp(parms[2])
  alpha<-exp(parms[3])
  pvec<-1- (1-r)^( (0:Nmax)^(1+alpha) )
  gN<-dpois(0:Nmax,lambda)
  gN<-gN/sum(gN)
  lik<-rep(NA,nsites)
    for(i in 1:nsites){
       lik[i]<-sum(dbinom(y[i],J,pvec)*gN)
    }
  -1*sum(log(lik))
}


nlm(lik,c(0,0,1),hessian=TRUE)

}