The legs and the underpart of the head are cast while the remainder is hammered.
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Young Grey Partridges are mostly yellow-brown and lack the distinctive face and underpart markings.
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The sexes look similar, but may differ in underpart colouration, especially on the rear flanks and under the tail.
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A part lying on the lower side or underneath an animal's body; "the warbler has a white throat and underparts"; "a woodland mouse with white underparts"
A lower or underneath part
(underparts) The whole underside of an animal from chin to tail (see venter).