- Cohen, J.A., and M.W. Fox. “Vocalizations in Wild Canids and Possible Effects of Domestication.” Behavioural Processes 1, no. 1 (July 1976): 77–92. doi:10.1016/0376-6357(76)90008-5.
- Tembrock, Günter. “Canid Vocalizations.” Behavioural Processes 1, no. 1 (July 1976): 57–75. doi:10.1016/0376-6357(76)90007-3.
Quotes from Reputable Sources
"Foxes can be quite vocal, and they make barks, howls, and whines. The sounds vary from a short, sharp "yap" or bark, followed by a "yap, yap," to a combination of screeches, yells, and long howls."
-- Maryland Department of Natural Resources (Red Fox)
"Red foxes vocalize with yips, barks, screeches, and other shrill sounds that function in long distance communication, e.g., to maintain contact between mates. Ritualized postures and stereotyped motion patterns serve as signals between individuals in close proximity. Tail and ear positions play a key role in these visual signals."
--Adirondack Ecological Center, SUNY (Red Fox)
"There have been 28 different kinds of vocalizations described in red foxes and individuals have voices that can be distinguished."
--Animal Diversity Web, University of Michigan (Red Fox)