Madre Selva field station, Depto Loreto, Peru. January 14, 2013.
We found several fuscus on the 2013 trip, from a yearling to this one, about five feet in length. This snake is very similar to the Forest Sipo (Chironius exoletus); the can be told apart by the number of scale rows at mid-body (12 for exoletus, 10 for fuscus). Additionally, in Chironius fuscus the lower portion of supraIabials are light colored, while C. exoletus usually features unicolored supralabials.
Peru 2013 Flickr album is here.
HerpMapper records for this species are here.