Helder was born in western Portugal and began birding at the age of 11. He is a founding member and vice president of the Portuguese Association of Bird Banders (APAA) after developing experience in bird banding with a special focus on the molt cycle in passerines. He is also the author and co-author of several articles and books on ornithology, and has been a voting member of the Portuguese Rarities Committee since 2018.
Helder has worked all over Portugal on various academic projects and environmental impact assessments, giving him a detailed knowledge of the species and habitats off the beaten track. In addition to birding, he also dedicates some of his time to other winged groups such as moths, butterflies, and dragonflies. Helder is a keen and enthusiastic interpreter of the natural world and now mostly spends his time as a tour leader for bird and nature tours in Portugal and Spain.
Helder is outstanding as a leader. He is an excellent birder (recognizes birds from flight patterns and behavior as well as appearance and call notes and songs) and also has excellent skills at managing people. He makes everyone feel important and valued as a group member. He is able to calm people and is able to arrange necessary changes. I would be delighted to travel again with him as a leader.
- Sandra J. on Portugal
Helder Cardoso was absolutely outstanding, a tribute to Portugal, all its natural habitats and most importantly its birds (and moths)...Helder is a rare person. As a guide, he was patient, vigilant and extremely knowledgeable...[We] remarked on how gentle and easy the birding day was. This was not for lack of pace or things to see, but because Helder is an amazing, skilled teacher. For those who listen to his answers, he is extremely adept at distilling the essence of a bird and its differences to similar species ... At meals we barraged him with questions and he patiently answered all of them. Personally, I was really impressed by his knowledge outside of birding....literature, world politics, the natural world and history. A true Renaissance man guided by noble values. Thank-you for an outstanding experience. You are truly a tribute to your country.
- J.C. B. on Portugal
Helder is a wonderful birder and a warm human being, with infinite patience and a great sense of humor. He went the extra mile to accommodate everyone's needs and interests.
- Lorie L. on Portugal
Helder Cardoso was just amazing! I don’t know how he managed to find all the birds he did but at times it seemed like magic. He knows the region and its birds thoroughly and is an expert “ear birder”. One faint chip and we got our target! He is also the nicest and most patient guide, as well as one of the most interesting and intelligent people I have ever met.
- Magda B. on Portugal