Bird Sudoku Level 109 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 109 Strategy
Hard Level 109 uses a 9x9 board with 29 perch cells, 11 blockers, and 8 habitats. Use the row and column counts first, then test each open diagonal flight line.
Bird Sudoku Level 109 Solution
Bird positions in the solution: R1C2, R2C5, R3C8, R4C2, R4C4, R4C6, R7C2, R7C4, R9C7, R9C8, R9C9.