This video from Texas in the USA is called Great Horned Owl Hooting; Territorial Evening Call At Sunset.
On Saturday 10 October 2015, there will be a conference about owls, in Schouwburg Ogterop, Zuideinde 70 in Meppel town in Drenthe province in the Netherlands.
This conference will start at 9:30.
There will be lectures on about all owl species living in the Netherlands, including barn owls, little owls and eagle owls.
Romke Kleeftstra will speak about short-eared owls and common voles.
Bart Ebbinge will lecture about snowy owls in the Arctic.
Karla Bloem will tell about great horned owls in North America.
The complete program is here.