Bird Sudoku Level 121 Hint
Pick a row, column, or habitat with a low remaining count, then check which of its perch cells are blocked by open diagonal flight lines.
Bird Sudoku Level 121 Strategy
Hard Level 121 uses a 9x9 board with 29 perch cells, 10 blockers, and 8 habitats. Use the row and column counts first, then test each open diagonal flight line.
Bird Sudoku Level 121 Solution
Bird positions in the solution: R1C5, R1C6, R3C1, R6C3, R6C7, R6C8, R7C3, R8C7, R8C8, R9C2, R9C3.