I have seen or caught small animals in the prairies that are now listed as extinct from before I was born or that their range never extended to where I saw/caught them. One such non-existent ranges was backed up for me by being included in a book of wildlife of the area and the animal listed in the local wildlife at an interpretive center for a park (also listed as a world heritage site). It appears that there is a targeted campaign to make these animals disappear to not be stopping development or agriculture. What can be done to keep these extinctions and endangered species from being hidden in the form of not being even listed? I included such a hidden endangered species (fictional) in a story I thought up but now it seems it is all too real. The species that brought this to my attention first was the Olive-backed Pocket Mouse (Perognathus fasciatus) when it was removed from the government lists of endangered species and added to a different list of extirpated animals (same as extinct but only for an area while some live elsewhere). What brought it to my attention today was the cute pygmy rabbit (Brachylagus idahoensis) and the last remaining related Columbia Basin Pygmy Rabbit (listed as the same species) that were captured and live in a captive breeding program. They show them as only living in the USA but I saw a mother with babies in Alberta Canada and evidence of others in the same area. The book mentioned above was about mammals of Alberta and included photos, track patterns and a host of information of what makes them unique (number of babies, the fact that they are one of only two species that dig holes... and block entrances with dirt to keep out snakes). This way I was absolutely sure what species they were.
Imagine this is a hamster-sized mother that is guiding her gerbil-sized very fuffy 12 babies down the hole before going down herself and blocking the hole with dirt almost instantly (they have special tunnel design for this). Note that being further north, the ones I saw were even fluffier then this one.