There are five species of fox in North America. They are the Red Fox, the Gray Fox, the Kit Fox, the Swift Fox and the Island Fox. The two species most often seen and heard are the Red and Gray Fox.
One afternoon I watched a Red Fox (Vulpes vulpes) in an alfalfa field in front of my home give an extremely loud and scary vocalization. If I had not seen the sound-maker I would have never guessed that it was an animal as small as a fox.
Red Fox (Vulpes vulpes)
Other than coyotes, foxes are the  animal that is the most mis-identified with bigfoot / sasquatch sounds. I have spoken with several excited witnesses who just knew what they recorded was a sasquatch but upon listening to their recordings it became evident that it was a fox.
For  previous posts about foxes please see:
Not So Distant Screams in the Night – Update
The following recordings demonstrate a few of the many sounds the Red Fox (Vulpes vulpes) uses.
File # 07 – 2009.05.01 – Red Fox # 2
File # 06 – 2009.05.01 – Red Fox # 1
File # 05 – 2009.04.08 – Red Fox # 1
File # 04 – 2009.04.01 – Red Fox # 1
File # 03 – 2007.08.11 – Red Fox # 1
File # 02 – 2007.04.07 – Red Fox # 1
File # 01 – 2007.01.04 – Red Fox # 1
Copyright 2004-2010 by Stan Courtney. All rights reserved. Reproduction in whole or in part without permission is prohibited.
I have red foxes around my house and grey fox. Ive heard their calls and let me say they are scary. Very raspy sounding. They repeat over and over again. Could easily frighten someone who is not used to hearing them. Great stuff Stan Keep up the great work.