noun which may take the genitive case particle 'no'
crepuscular
Biology term describing animals active primarily during twilight (dawn and dusk).
猫は薄明薄暮性の動物だと言われる。
Cats are said to be crepuscular animals.
薄明薄暮性の種は、夜行性とも昼行性とも異なる活動パターンを持つ。
Crepuscular species have activity patterns distinct from both nocturnal and diurnal ones.
Compound of 薄明 (twilight, dawn) + 薄暮 (dusk, twilight) + 性 (nature, -ity). The exact derivation is uncertain, but it is a modern technical coinage in biology.