10.1371/journal.pone.0174433.g001 Emily B. Dennis Emily B. Dennis Byron J. T. Morgan Byron J. T. Morgan Stephen N. Freeman Stephen N. Freeman Martin S. Ridout Martin S. Ridout Tom M. Brereton Tom M. Brereton Richard Fox Richard Fox Gary D. Powney Gary D. Powney David B. Roy David B. Roy Efficient occupancy model-fitting for extensive citizen-science data - Fig 1 Public Library of Science 2017 site occupancy modelling approaches alternative New Millennium data base species tool variation opportunity Efficient occupancy model-fitting UK citizen-science data covariate 2017-03-22 18:30:26 Figure https://plos.figshare.com/articles/figure/Efficient_occupancy_model-fitting_for_extensive_citizen-science_data_-_Fig_1/4779289 <p>a) The number of BNM records as a function of time and b) the number of sites (1 km squares) with records each year.</p>