Behind the name "Ulfhrafnar" lies the relation between wolves and ravens in nature. This relation can be transfered to the relation between a small warband and the large Hethen army of the Vikings. Ravens are often called wolf-birds and it is this name we have taken one step furhter to wolf-ravens.
On http://wolfandravens.blogspot.co.uk/ is a very well written description of this relation, from which the text below is found.
Very few mammals have symbiotic relationships with other animals. One of the few exceptions is the raven and the wolf. Ravens are sometimes known as "wolf-birds" because they form social attachments with wolves. Where there are wolves, there are often ravens that follow wolves to grab leftovers from the hunt, and to tease the wolves. They play with the wolves by diving at them and then speeding away or pecking their tails to try to get the wolves to chase them.
Wolves and ravens have long been connected in folklore and fact. The Nordic God Odin is often represented sitting on his throne, flanked by his two wolves Geri and Freki and two ravens Huggin and Munin. Tales of hunting interaction involving wolves, ravens and humans figure prominently in the storytelling of Native American tribes of the Pacific Northwest and Alaska, with the ravens appearing as form-changing wise guys and tricksters, taking advantage of both humans and wolves.
Ravens are possibly the most intelligent birds, based on their omnivorous adaptability to almost any environment, their fascination with colourful toys and glittery objects, their use of natural tools, and their diverse repertoire of sounds and vocalizations. Wherever wolves hunt, ravens are usually present, scavenging prey and sometimes leading wolves to potential prey or to carcasses too tough for even the ravens' heavy, pick-like beaks to penetrate.
Ravens not only scavenge wolf kills, but steal up to one third of a carcass by continually carrying away chunks of meat, caching and hiding them both from the wolves and their fellow ravens. A fascinating new study suggests that since an adult wolf can by itself kill any prey smaller than a large moose, the real reason wolves hunt in packs, is to minimize the portion of a carcass lost to ravens! And while it may seem that wolves have the short end of this symbiotic relationship with ravens, idle wolves and ravens have been observed playing together, with ravens pulling on wolf tails, and wolf cubs chasing after teasing ravens.
Some zoologists speculate that the raven's relationship with wolves may be because of their psychological make-up. Dr. L. David Mech wrote in "The Wolf: The Ecology and Behaviour of an Endangered Species": "It appears that the wolf and the raven have reached an adjustment in their relationships such that each creature is rewarded in some way by the presence of the other and that each is fully aware of the other's capabilities. Both species are extremely social, so they must possess the psychological mechanisms necessary for forming social attachments. Perhaps in some way individuals of each species have included members of the other in their social group and have formed bonds with them."
In "Mind of the Raven: Investigations and Adventures with Wolf-Birds," zoologist Bernd Heinrich has suggested a basis for this association. Ravens lead wolves to their prey, alert them to dangers, and are rewarded by sharing the spoils. He wrote: "Ravens can be attracted to wolf howls. The wolves' howls before they go on a hunt, and it is a signal that the birds learn to heed. Conversely, wolves may respond to certain raven vocalizations or behaviour that indicate prey. The raven-wolf association may be close to a symbiosis that benefits the wolves and ravens alike. At a kill site, the birds are more suspicious and alert than wolves. The birds serve the wolves as extra eyes and ears."