He made several foreign trips to collect specimens, including visits to Burma (1885–89) and the Cape Verde Islands (1898), the islands in the Gulf of Guinea (São Tomé, Príncipe, Fernando Po, Annobón, 1900–02) and Cameroon and French Congo (1902).

[1] He spent four years in Burma, accumulating large collections of insects and birds.

He then planned an expedition to Malaysia, but his poor health made it necessary to choose somewhere with a drier climate, hence his visit to the Cape Verdes.

He was disappointed by the amount of wildlife he found there, but was still able to collect forty-seven species of birds, eleven of which were new for the islands.

While on the Cape Verde Islands Fea collected a specimen of an unknown petrel.