We have two English/Dutch speaking guides in the area and two guides who only speak Spanish.

English and Dutch speaking:
Discover-extremadura.com (bird-watching and nature guides with focus on Villuercas Ibores Jara)

Spanish speaking:

Near Cañamero, on the entrance road to the Cancho del Fresno Reservoir, is the ZEPA information Centre. The opening hours are Wednesday trough Sunday from 10 AM to 2 PM. But information is only available in Spanish.