Little Man was America's ideal of a llama. Beautiful, gentle and heroic, he died in 2011 of presumed smoke inhalation after saving his owner's flock of sheep from a wildfire in Hesperia, Calif.

It's just one example of why Americans have pursued this curious animal over the decades. Thirty years ago, in fact, there were only a handful of llamas in the United States. Then Americans took an interest in the beasts for their docility, endearing features and usefulness as guard animals. The size of the country's herd roughly quadrupled in six years, reaching 12,116 by 1986, and increased tenfold over the next twenty years to 122,680 in 2007, according to the census of farms and ranches conducted by U.S. Department of Agriculture.

Since then, however, the American commercial llama herd has diminished by 38 percent, possibly because many producers sold or gave away animals to amateurs. There were just 76,086 llamas in the United States in 2012, the most recent year for which data are available, mostly in Arizona and the Pacific Northwest. That reduction is unsurprising, given the history of extraordinary prices paid for breeding llamas at auction.

In The Huffington Post, Ben Walsh cites a 1984 article from The Bend (Oregon) Bulletin noting that a mature female of good pedigree could fetch as much as $20,000. A few years later, a young stud sold for $130,000 at auction in Omaha. And Llama Life II, a trade publication, reported the sale of a herdsire for no less than $220,000 in 2003. The federal statistics show that the average price of a llama in 2012 was just $820, less than what The Bulletin reported as the price of average male 28 years earlier.

Prices like these have always led to speculation that there is a bubble in llamas, as Walsh argues. To be sure, many amateurs have likely lost thousands hoping to make money by breeding the creatures, which were domesticated millennia ago in South America. They have little commercial usefulness, producing only small quantities of inexpensive wool. "Llamas really aren't much good for anything," The Bulletin concluded.

That fact has encouraged comparisons with ostriches and emus, two species that witnessed a bubble in the United States and Canada during the Clinton administration. Speculation has also led to bubbles in chinchillas, Merino sheep, Shetland ponies and Berkshire hogs, write Tina L. Saitone and Richard Sexton, agricultural economists at the University of California, Davis.

They concluded recently that another bubble had formed and burst in alpacas, a smaller relative of the llama with finer wool. Prices for male alpacas declined by roughly 80 percent between 2005 and 2011. You can now readily find them for free online, Sexton said in an interview.

Sexton said he was not aware of a bubble in llamas, and it is possible that many purchasers are mainly looking for pets -- in contrast to the market for alpacas, which were promoted as an opportunity for business. Yet he added that since reliable information on prices for exotic livestock is impossible to come by, it is difficult to say to what extent llamas have been overpriced.

"One of the reasons we end up getting these speculative bubbles is at least for exotic types of creatures, there’s no systematic gathering and reporting of price information," he said, noting that speculation in unusual agricultural commodities dates at least to the Dutch tulip bubble of 1637.

"There's this very common pattern where there's not objective information, a very tightly knit group produces this commodity, and they start reinforcing each other's expectations," Sexton said. "It can create that herd mentality."