A ten-year effort to save California’s endangered riparian brush rabbit seems to be paying off. The rare species can be found in the San Joaquin River National Wildlife Refuge west of Modesto. Alex Breitler reported on Recordnet.com that the population of wild bunnies may very well be on the increase for the first time in recent history. Here are highlights of his article:
Valley rivers were once lined with the kind of jungle-like vegetation the rabbits require. But that habitat was torn out to make way for farms and cities.
In the 1990s, only one surviving population of rabbits was known to exist, at Caswell Memorial State Park in south San Joaquin County. At times the population there might have numbered merely in the dozens.
The likelihood of the entire species being wiped out in one catastrophic flood seemed high.
So state and federal biologists – in partnership with the Endangered Species Recovery Program based at California State University, Stanislaus – began capturing rabbits and placing them in pens, encouraging them to reproduce. The bunnies obliged, as bunnies usually do, and for years their progeny were released at the river refuge south of Caswell, as well as a couple of other locations where populations are now known to exist.
More than 1,000 rabbits have been released since the breeding program began with a male and female named Adam and Eve.
Patrick Kelly, a professor of zoology and coordinator of the endangered species program, is hesitant to put a firm number on the total population. The rabbits declined after a 2006 flood, rebounded and then dipped again after a 2011 flood.
During that second flood, however, many rabbits survived by scampering to specially designed bunny mounds where they could escape the high waters. In turn, the recovery this time seems more rapid.
“I’ve been leery about saying the population is in the thousands,” Kelly said. “But it’s looking promising.”
Twice a year, rabbit rescuers spend two weeks attempting to survey the population as best they can. They set out traps across the refuge, baiting them with horse feed. Rabbits and an assortment of other animals sniff their way inside, stepping on a pressure plate that closes the door behind them.
Each morning the traps are checked, captured rabbits are briefly studied, and then the cages are reset for whatever might turn up the next night.
On this particular morning, Lloyd is having little luck. Trap after trap is empty. Two mouse-like voles and an angry rat are the only discoveries.
Then Lloyd’s cellphone rings. Another team has discovered a trap containing a baby riparian rabbit – perhaps no more than 30 days old.
Lloyd quickly finishes his work, then heads to the scene. Sure enough, the little guy is waiting calmly for his release.
Normally, there is a bit of poking and prodding before that can happen. Tissue samples are taken from the ears (being careful to avoid veins), a microchip is inserted between the shoulders, and height and weight measurements are taken.
“They put up with a lot,” said Kelly, watching nearby.
But it turns out this hungry bunny has been captured before. The previous night, in fact.
He left his nest no more than two weeks earlier to find his way in the world. “And obviously he’s found his way back into this trap,” Kelly said.
The bunny is soon set free and, with only brief hesitation, vanishes into the brush.
To read the complete article online, please visit: http://www.recordnet.com/apps/pbcs.dll/article?AID=/20130507/A_NEWS/305070322
Hoppington Post congratulates Patrick Kelly and his team at California’s Endangered Species Recovery Program for their apparent success in saving their state’s rare riparian brush rabbits from the brink of extinction. It is our hope that the habitat these and all wild rabbits need for survival can not only be spared from future development, but hopefully increased to help them compete with the many predators that also live in the areas.
Photo courtesy of USFWS Pacific Southwest Division