Bird Sudoku Level 164 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 164 Strategy
Hard Level 164 uses a 9x9 board with 29 perch cells, 10 blockers, and 9 habitats. Use the row and column counts first, then test each open diagonal flight line.
Bird Sudoku Level 164 Solution
Bird positions in the solution: R1C7, R1C9, R2C5, R3C1, R5C9, R6C5, R6C6, R6C7, R7C2, R8C2, R9C4.