News From the Friends of Laguna Atascosa National Wildlife Refuge

The two last known breeding populations of ocelots in the United States, estimated to be about 50 individuals, all live in the southernmost tip of coastal Texas.   Saving them from extinction is a multifaceted undertaking combining science, technology, politics, funding, government, private organizations and individuals, dedication, passion, tragedy, and joy.  Few stories can illustrate the complex efforts to protect the endangered ocelots better than that of ocelot male 276 (OM276) as told by US Fish and Wildlife biologist Mitch Sternberg.

The Story of Ocelot Male 276

The story of male ocelot 276, otherwise known by the Adopt an Ocelot Program as “Son of Houdini”, starts when he was first captured during work by the Ocelot Monitoring Program at Laguna Atascosa National Wildlife Refuge on February 23, 2011.  At that time, he was estimated to be 3 years old and weighed 19 lbs.  Due to his size, weight and overall condition, he was estimated to have been born sometime in 2008.

Because staff had difficulty locating him when radio-tracking him or spotting him on wildlife cameras for several months, biologists assumed he lived mostly near the refuge on ranches where he may have been born.

He was caught again only 25 yards away from General Brant Boulevard (FM 106) on 18 April 2013, weighing 22 lbs. His capture was part of a partnership project by the U.S. Fish and Wildlife Service to conduct environmental monitoring on behalf of the Texas Department of Transportation (TxDOT).  The monitoring was intended to evaluate the effectiveness of 9 potential wildlife crossings with fencing which will be used to funnel animals under the Farm to Market Road (FM) 106 expansion project. The ocelot was one of 14 ocelots and 3 bobcats being monitored by the U.S. Fish and Wildlife Service at Laguna Atascosa National Wildlife Refuge.

Male 276 was released safely in 2013 with a brand new radio collar – this time, one that collects very accurate location data using GPS technology.  These GPS collars email the data to Refuge Biologists when the ocelot is within the cell phone coverage area.  The data is invaluable.  It does not require tracking ocelots all over Cameron County into the “wee hours of the night”, significantly reducing staff safety concerns.  Equally important, it also gives us the ocelot’s locations from places where the older style of radio collar would not be reachable with our ground-limited equipment, such as in roadless areas, or when the ocelot has wandered into areas far away and unknown to us.

His movements were like nothing we had seen in almost 30 years of radio-tracking ocelots in South Texas, or the U.S. for that matter.  He covered some serious ground… all in search of mates!  Healthy and in his prime, he was out to discover the limits of his new adult territory and visit as many females as he could.

The drive to find mates is a powerful force.  This drive pushes males to travel long distances because native thornscrub habitat is severely fragmented by development and extensive agricultural fields that offer little cover.  The result is small segregated ocelot populations and some individuals that are quite isolated.

For female ocelots, the drive to reproduce and raise kittens is powerful as well.  However, females normally do not disperse long distances, rather they find a territory where they can catch just enough food and provide suitable shelter to protect and raise their young.  Normally a wild male feline, such as the ocelot, would try to acquire and maintain a territory big enough to encounter as many females as possible – usually 2-4 females.  Unfortunately, in these droughty times since about 1999, males have been lucky if they have frequent access to even 1 female, as there is fierce competition for access to mates.

The data collected from the GPS collar has shown us that male ocelots are able to cover extensive areas and cross some roads (See map at end of story) very frequently without incident, but has also validated exactly what we feared – that high speed road areas where ocelots have died before are in desperate need of functional wildlife crossings.

Male 276 travelled to various Refuge tracts on State Highway (SH) 510 east and west of Bayview, Bahia Grande near SH 100 and important private lands all around Cameron County.  At a minimum, he crossed several heavily trafficked roadways numerous times: FM 106 at least 47 times, FM 510 over 17 times, FM 2925 near Arroyo City 4 times, and FM 1847 four times!  He used areas slated for wildlife crossing construction under roadways and used areas not currently funded for the construction of wildlife crossings.  Within the scant 6 months that we were able to track him so accurately, he had been very close or in the city limits of Arroyo City, Bayview, Laguna Vista, and Rio Hondo.  Overall, he wandered in an area 17 miles east to west and 18 miles north to south.  (See map at end of story)

Movements of Male Ocelot 276 highlight the importance of the private ranches that have maintained or restored their thornscrub habitat.  Thornscrub ranches provide great habitat for conservation of our wonderful South Texas wildlife, including endangered ocelots.  Even ranches that focus on cattle ranching along the coast tend to have some areas of thornscrub cover and even thin strips of thick brush that can be used by ocelots to move across the landscape.

Sadly, the story of male ocelot 276 came to a tragic end on November 7, 2013, when he was struck and killed by a vehicle at the base of the concrete barrier along SH 100 east of Los Fresnos, Texas.  The ocelot was discovered the following morning by a member of the public who, thankfully, reported the incident to the U.S. Fish and Wildlife Service.  It is suspected that ocelots that are not tracked by biologists may be killed on roadways, but are not reported and/or are taken from roadways by the public and possibly disposed of without reporting the sighting to state or federal agencies in desperate need of the information.  The locations of these sightings are critical for saving the ocelot, as well as informing the Texas Department of Transportation (TxDOT) where wildlife-roadway crossings are needed.  A wildlife crossing sign warning motorists has recently been posted by TxDOT on SH 100 where OM 276 was killed.

Although loss of habitat is the single greatest threat to the cats, an estimated 40 percent of ocelots from Laguna Atascosa NWR that have been studied over a 30 year period have been killed by collisions with cars.  That is the largest mortality factor for ocelots by far!  That is why we have been so serious in limiting public driving access to parts of Laguna Atascsoa NWR where ocelots are known to live.  We simply can’t afford to lose any more ocelots to vehicle strikes, especially from such a small population.

Contiguous concrete barriers placed in the center of roadways, like those found on State Highway 100, are especially hazardous to ocelots and other wildlife that become trapped in the roadway and panic.   Even though ocelots are physically capable of jumping over the barriers, they won’t do it because they can’t see what is on the other side.  Instead they travel along the barrier looking for an opening.  Even larger animals like white-tailed deer and nilgai antelope will follow the barrier rather than jump over it, even when approaching vehicles are threatening them.

Since 2005, the Service has been working with TxDOT to consider alternatives to the concrete road barriers on roads like State Highway 100.  More than six miles of contiguous concrete barriers were installed east of Los Fresnos to Laguna Vista, Texas, in 2007.   This is the second documented ocelot to be killed on this segment of SH 100 since 2010 and at least one other ocelot was killed there by a vehicle in 1994.

Ocelots, like bobcats and numerous other mammals, use brushy areas for travel corridors.  When the road bisects a brushy patch, a canal, or a resaca (old streambed), there is usually brush along their margins which wildlife use for travel.  Therefore, these areas are in serious need of functional wildlife crossings.  TxDOT has agreed to install wildlife crossings along FM 106 and SH 100.  These will make the roads safer for wildlife, as well as for drivers.

The Friends of Laguna Atascosa NWR have been instrumental in supporting ocelot conservation with funds donated by concerned individuals, received through grants, bookstore sales, fundraising events, an “Adopt an Ocelot” program, and sales of Texas specialty ocelot license plates (go to Save Texas  100% of these funds are used to support a wide range of refuge projects including the purchase of the monitoring equipment that made the tracking of this elusive ocelot possible.  Without the use of these GPS collars, it is unlikely we would have known about the incredible long-distant movements of this ocelot.  The movements of this particular male highlight the ability of ocelots to disperse and potentially find mates in faraway places….if they do not encounter significant barriers.

The U.S. Fish and Wildlife Service, TxDOT and Friends of Laguna Atascosa National Wildlife Refuge, together with other conservation partners, will continue to protect the ocelot as part of our everlasting South Texas natural heritage, helping honor the legacy of OM 276.


The heartache of OM276’s death lingers in all of us who care so deeply about ocelots and wildlife conservation in general.  Fortunately, recent photos taken with research cameras on Laguna Atascosa National Wildlife Refuge have given us cause for great celebration.  A new ocelot kitten, believed to be a female, was documented on Valentines Day, 2014.  Enjoy the photos and celebrate with us!

Many people have asked what they can do to help in the ocelot conservation effort.  Sharing this story with family and friends is an excellent way to spread the word about the plight of the ocelot.

Another way to help is to make a donation to The Friends of Laguna Atascosa National Wildlife Refuge, a non-profit organization dedicated to supporting the conservation mission of the refuge.  100% of all donations made to the Ocelot Conservation Fund go to this purpose.

Donations can be made to:

Friends of Laguna Atascosa National Wildlife Refuge (FLANWR)

Ocelot Conservation Fund

22817 Ocelot Road

Los Fresnos, TX 78566

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