The 2 photographs of what appears to be a juvenile male do not match any images in my field guides. I'm guessing at the identification, because it was the most likely match.
(Aegorhinus vitulus) Caballito del Monte was not listed on inaturalist.org, except for this subspecies "bulbifer". That is the only reason I chose this subspecies.
The insect resembles the one listed in Project Noah - http://www.projectnoah.org/spottings/36267018
As the fox hunts along the edge of the river, a family of Flightless Steamer Ducks watch it from water.
Ided from book. Rusty neck