(KPIX 5) –Don’t try to sell a wild animal unless you know the laws, because law enforcement is watching.

Al Colby, an undercover agent for the U.S. Fish and Wildlife Service is on the hunt for illegal wildlife sold on the Internet.

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“If there’s a market and money to be made, someone is going to do it,” Colby told KPIX 5.

Colby has seized all kinds of contraband over the years, from tigers to wolves, monkey skulls, even a guitar made out of a giant sea turtle. Organized crime, he said, is behind some big ticket items.

Last year, a Texas man pleaded guilty to smuggling rhino horns worth $50,000 a pound to China. Authorities believe he was part of an international criminal enterprise.

But amateurs are out there as well. California Fish and Wildlife agents recently busted a San Jose woman for buying an owl on eBay. Her apartment was full of stuffed exotic animals. Agents seized dozens of them but left others, including an African lion.

“It’s legal,” said Colby.

The agent admits it’s complicated. International and federal laws come into play. Take the lion for example. Anyone can own or sell one without a permit. But one needs a permit to sell a duck.

“That falls under the Migratory Bird Treaty act,” said Colby.

Every state has different laws as well. Trading bears and bear parts is legal in other states, but not in California.

“In California you can legally hunt a bear with your valid hunting license, you can possess a bear that you legally acquired, but you can’t sell it,” said Colby.

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It was a grizzly that got Jim Dickson in trouble. “The punishment I got didn’t fit the crime,” he said.

Dickson is a collector and his house is packed with boxing and gold rush memorabilia. He also collects wild animals.

“I had a 9-and-a-half foot Kodiak, I had another grizzly bear,” he said.

A few years ago, in need of some quick cash, he posted one on Craigslist. Sure enough, Colby spotted it and paid Jim a visit, during which the undercover agent spotted one of the biggest no-no’s in the animal trade: an eagle.

Suspecting nothing, Dickson sold it, and ended up serving 6 months in prison.

“When they found out I was in there for animals, stuffed eagle, they laughed. They thought it was a joke,” he said.

But it was no joke: the feds seized most of his animal collection, worth $50,000. They left him just one bear, as a grizzly reminder.

“I just wanted to build a museum, that’s the only thing I wanted to do, not hurt anybody else,” he said.

Dickson’s just finished three years of probation. He says he’s winding down his collecting hobby, and he’s definitely done with animals.

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Editor’s Note: Special thanks to the Lindsay Wildlife Experience for video of some of their taxidermy exhibits. The exhibits can be rented out for educational purposes. http://lindsaywildlife.org/teachers-and-schools/