At present open to any setter, if I correctly interpret the "film-ese"...
There's a venerable and much-loved English work of fiction -- generally seen as a "children's classic", but reckoned to have been enjoyed from first publication to the present day, by "kids from nine to ninety" -- whose main characters are assorted members of Britain's fauna. And there's a present-day English fiction author, among whose various works are books concerning a particular wildlife species; one member of which species, is a key character in the older work which I've mentioned. (The books by the modern author alluded to, are reckoned to be an attempt to do for this species, what Richard Adams did for rabbits.) The modern author has also, subsequently, published sequels to the older work by the long-ago writer; featuring essentially the same characters.
Please furnish:
Title and author's name, of the initially-mentioned "venerable and much-loved" book.
Name of the modern author.
Which species of our wildlife it is, that is prominently featured as described above, in both "ancient and modern".