 <unk> of the Réunion ibis show that it was more robust , likely much heavier , and had a larger head than the African sacred and straw @-@ necked <unk> . It was nonetheless similar to them in most features . Rough <unk> on the wing bones of the Réunion ibis are similar to those of birds that use their wings in combat . It was perhaps flightless , but this has not left significant <unk> traces ; no complete skeletons have been collected , but of the known pectoral elements , only one feature indicates reduction in flight capability . The coracoid is elongated and the radius and <unk> are robust , as in flighted birds , but a particular <unk> between a <unk> and the <unk> is otherwise only known from flightless birds , such as some <unk> , <unk> , and several extinct species . As contemporary accounts are inconsistent on whether the solitaire was flightless or had some flight capability , <unk> @-@ <unk> suggested that this was dependent on seasonal fat @-@ cycles , meaning that individuals <unk> themselves during cool seasons , but were slim during hot seasons ; perhaps it could not fly when it was fat , but could when it was not . However , Dubois specifically stated the solitaires did not have fat @-@ cycles , unlike most other Réunion birds . 
