Rancher Joseph L. Torres knew one of his cattle had gone missing, but when he found out what had happened to the six-month-old heifer he was astonished.

His son had gone hunting on the family ranch 40 miles west of Trinidad on the Sunday before Labor Day, about a month ago, and came upon the remains of the heifer. The dead animal was missing its uterus, tongue and part of one ear, yet there was no blood in the area or signs of human presence.

Torres said he went out to confirm his son's report of the dead heifer, but found a black bear feasting on the dead cow. Still, he was able to confirm what his son had described. He called the sheriff's department, which arrived the next day.

Torres said he still can't understand what happened to the heifer. He estimated the monetary loss as being $700 to $900.

"It was a really scary thing to see, and I felt terrible for that poor animal," Torres said. "Bears don't remove body parts that way, so it had to be something else. Another strange thing was that all the vegetation around the animal was dead, for about a 12 to 14 foot area."

It's not the first cattle mutilation reported in Las Animas County in recent years. Rancher Mike Duran reported a similar cattle mutilation that happened on his nearby ranch in 2009. Many of the details of the two deaths are similar, so Duran contacted Torres when he heard about the recent incident.

One of Duran's cows was killed in 1995, with its udders removed and other body parts missing, also with no evidence of blood in the area. Duran checked out the death on the Torres ranch and got in touch with Chuck Zukowski, who has researched many similar incidents in his work with Colorado Springs-based Mutual Unidentified Flying Objects Network (MUFON).

Zukowski and other MUFON researchers visited the Torres ranch shortly after the recent incident, taking photos and measurements to compare the mutilation with similar incidents that have occurred across the West since the 1970s. MUFON tries to determine whether there is a link between reported UFO sightings and cattle mutilations that occur at about the same time and place.

"One of the first things we look for is blood," Zukowski said last week. "In the Torres case, as in so many others we've investigated, there's little or no sign of blood. There's usually no sign of a struggle, and the animal is just lying there. There's also no sign of human intervention or predatory animal attacks that led to the death. One reason we think it might be UFOs doing this is that there are often signs of animals being moved from place to place, that is, grabbed in one area, eviscerated in another and dropped in a third area. There is no natural predator that we know of who could do that. The possibilities are almost endless."

Unexplained cattle mutilations have been recorded in a variety of locations in the region for decades. An official explanation for the phenomenon has yet to be determined. Las Animas County and neighboring Colfax County, N.M., experienced a large number of mutilations from the mid-1970s to the mid-1990s. A film crew was in Trinidad last winter shooting a sequence for a new series to run on the Sci-Fi Channel about the unexplained.

Zukowski said law enforcement authorities have begun taking cattle mutilation reports more seriously. He said the Las Animas County Sheriff's Department seems to be taking the reports seriously.

"They have come out soon after these reports and do thorough investigations, but like everyone else they're mystified by what's going on in these cases," he said.

Torres said he's a little leery about going out to round up his cattle this fall with the memory of the recent cattle mutilation still fresh in his mind.

"It kind of holds me back when I think about going out all alone to get them down here for the winter," he said. "I have no choice. I have to take care of those cattle."