Modern tiers are faced with a choice now that the birds that were rare then have become even rarer (or extinct): Tie with something else, or find a source of authentic feathers.
The segment was an interview with the author of The Feather Thief[0], who investigated the lengths one "enterprising" tier went to to acquire authentic feathers, destroying the historical scientific record for whole species in the process.
It seems insane that a fad of rich men from a long time ago becomes the obsession of a subculture of the larger fly tying community and that the result of that is a hole in the scientific record. It's enough to make you wish that folks would get obsessed with growing rare pineapples instead.
[0] https://www.goodreads.com/book/show/44153387-the-feather-thi...