If we're being honest, the Omiltemi cottontail rabbit (Sylvilagus insonus) is not much to look at. It's a fairly conventional bunny: long ears, strong hind legs, short tail, a little chubby. Except that this particular rabbit had not been seen by scientists for more than 120 years – until now. A five-year-long expedition led by José Alberto Almazán-Catalán, ecologist and president of Instituto para el Manejo y Conservación de la Biodiversidad (INMACOB) turned up conclusive camera-trap evidence that the elusive lagomorphs are still hiding out in the conifer forests of Mexico's Sierra Madre del Sur mountains.

The research team began their search in the forested areas around Chilpancingo, the capital city of Guerrero, where the Omiltemi cottontail rabbit was first documented by Edward William Nelson in 1904. However, they turned up rabbit-less. A year or so later, they shifted their focus to high-elevation conifer forests where they were more confident they would be successful, especially after locals in the area told the team that they regularly hunt Omiltemi cottontail rabbits before handing over several carcasses.

When the hunted rabbits were compared to museum specimens and Nelson's original description, the fur colour, body measurements and cranial characteristics were a match. All that was left to do was strategically set up remote camera traps to confirm the find. The area's Omiltemi cottontail rabbits came to the party. They hopped into frame in seven of the ten areas that the expedition team surveyed. The find marks the 13th species rediscovered as part of Re:wild’s Search for Lost Species – a global effort to find and protect species that have not had a scientifically documented sighting in at least 10 years, but are not considered extinct.

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Image © Alberto Almazán Catalán

“Just knowing that it had been 100 years, and no other scientist had seen a live [Omiltemi] rabbit is incredible,” Almazán-Catalán told Re:wild. “It's totally different from the regular cottontail, and I was completely amazed and very happy to have had that opportunity to see one.”

The rabbit's name is something of a red herring. Omiltemi cottontail rabbits don't have cottontails. In fact, their tails are short and black, a physical feature that sets them apart from many other rabbits, along with their smaller stature and less elongated ears.

Of course, there is still much to learn about a species that scientists hadn't seen in over a century. The team are hoping to glean more info about the Omiltemi cottontail rabbit's behaviour, ecology and population size.

“Eighty percent of the objectives of this project have been achieved,” said Almázan. “However, we still need to learn more about the natural history of this species; especially information about what it does between January and June, which is its reproductive season and when the greatest numbers of the species have been recorded. In addition, we need to better understand the local knowledge of the Omiltemi cottontail rabbit and the role the species plays in its distribution area. It’s also going to be important to design conservation proposals with local residents, municipal authorities and the National Commission of Natural Protected Areas (CONANP).”

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A Omiltemi cottontail rabbit caught on camera trap at night. Image © Joe Figel

Local community members are keen to help protect the species if research indicates that poaching and subsistence hunting are damaging populations. The rabbits seem to be more abundant in summer with both locals and the expedition team themselves spotting more of the animals during warmer months.

“This search was full of unexpected turns and employed everything from interviews to drones to find this little rabbit,” said Christina Biggs, lost species officer for Re:wild. “We applaud these tenacious and comprehensive efforts as they provide crucial updates for our partner IUCN Red List assessors to better make recommendations for species survival. Alberto and his team are helping fill a huge knowledge gap to make sure that the Omiltemi cottontail rabbit is never lost to science again.”