Earlier this week, U.S. border patrol agents investigating a suspected illegal crossing at the U.S.-Mexico border in Texas were shocked to discover a male tiger cub stuffed in an abandoned duffel bag. The cub, not more than a few months old, was unconscious and in serious need of medical attention.

"Not your average day in the field," Irma Chapa, communications director for Rio Grande Valley Sector Border Patrol, tweeted.

The cub was immediately transferred to the Gladys Porter Zoo, which specializes in the treatment of endangered animals. As of Tuesday evening, the staff reported that the young tiger was stabilized and doing well. It's expected that he will make a full recovery.

According to a 2016 fact sheet from the conservation organization Defenders of Wildlife, more than a quarter of the nearly 50,000 illegal shipments of wildlife and wildlife products seized at ports of entry from 2005 through 2014 came from Latin America. Many, like the Bengal tiger cub discovered sedated last year, are transported in hidden compartments within vehicles.

“Coming from Mexico, there’s a lot of vehicle traffic, and neither customs or us can catch everything," Nicholas Chavez, the southwest region special agent for the U.S. Fish and Wildlife Service, told National Geographic in 2017. "There aren’t enough agents and it’s all throughout the border."

In addition to big cats, border agents have also seized monkeys, parrots, endangered turtles, and even cobras hidden in potato chip cans. If they survive the journey, they can often demand thousands of dollars on the black market.

"If it walks, crawls, swims, flies — somebody eats it, collects it, wears it or wants to," Joseph Johns, a federal prosecutor of environmental crimes, told NPR.

Unfortunately for those species caught up in illegal smuggling, the problem isn't expected to get better anytime soon. A recent investigation by the San Diego Union Tribune found that inspectors were only making about 11 seizures a day for the entire country. Complicated rules for importing and exporting live species, legal loopholes, and understaffed federal inspection teams are just some of the forces working against putting a dent in the estimated $2 billion annual U.S. illegal wildlife black market.

“I think the U.S. Fish and Wildlife Service is doing the best job they could possibly do, but the resources are just grossly inadequate,” Donald Barry, senior vice president of species conservation at Defenders of Wildlife told Mongabay . "So it’s really up to this country to decide what we’re prepared to prioritize — or not. I would hope that as we become more aware of this problem, we step up and begin to take the steps that are necessary to crack down on, and keep the illegal wildlife trade away from our shores."

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.