A. palustris (lower) and scirpaceus (upper), mixed ages and seasons. The leg colour is generally darker in scirpaceus, but extensive variation (partly due to the age of the bird) makes the character dangerous to use. The colour of the claws gives better guidance: In scirpaceus dark above, clearly contrasting to the underside, while palustris are paler above, less contrasting to the underside. Note, however, that individual variation makes a few birds more difficult - for example the shown upper-right scirpaceus with pale claws. Note also the tendancy for palustris to show slightly thicker legs.