House Finches
   Single Species Multi Season
   Ships with Presence

In 1942 a small population of house  finches (Carpoldacus mexicanus) 
released in Long Island, NY. Population has expanded
since then.

The North American Breeding Bird Survey (BBS) used to track expansion.

26x 100-km distance bands from LINY established.
Total of 694 sites (multiple in each band) established.
Six 5-year periods (starting in 1976) define the seasons, i.e. season
1 is from 1976-1980, season 2 is from 1981-1985, etc.

50 stops in each season defined as "visit" to the site (not ideal).
Covariates:
   Distance from point of release in units of 1000 kms, i.e.
      distance band 0.1 = 100-199 km from release point.
   Detection prob as function of distance \crudely" modelled
     using f = f0; 1g if    Finches detected on more than 10 stops in PREVIOUS years.