Bird Sudoku Level 171 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 171 Strategy
Hard Level 171 uses a 9x9 board with 29 perch cells, 7 blockers, and 7 habitats. Use the row and column counts first, then test each open diagonal flight line.
Bird Sudoku Level 171 Solution
Bird positions in the solution: R1C3, R2C6, R3C2, R3C6, R4C8, R5C6, R6C6, R8C9, R9C4, R9C5, R9C6.