FIGURE 3 in Two centuries of ornithological exploration of the Rio Doce Basin, southeastern Brazil. Part II-A catalogue of its birds and a gazetteer

FIGURE 3. Sampling effort in the Rio Doce Basin, southeastern Brazil, measured as the number of bird records per each 0.25° x 0.25° grid cell, irrespective of the sampling method used. Note that several cells have never been sampled for birds, while a few cells have been heavily sampled.