Bighorn sheep on an upward trend
Article Launched: 03/09/2007 12:00:00 AM PST
The population of bighorn sheep in the San Gabriel Mountains is growing, according to results from a comprehensive field survey completed two weeks ago by the Department of Fish and Game, the U.S. Forest Service, and more than 100 volunteers who took part in the counting effort.
The ratio of lambs to ewes was the highest ever recorded since surveys began in 1976, an indicator of a healthy and growing herd.
The bighorns were counted from the air, by DFG and USFS staff in a helicopter, and from the ground by volunteers in all of the major sheep habitat in the mountain range. A total of 142 sheep were counted from the air and another 55 from the ground, said DFG biologist Jeff Villepique. Since the ground and air surveys were conducted simultaneously, Villepique said they were able to estimate the total population with a high degree of accuracy at 308 animals. This is up slightly from last year's 292 estimate.
Once the largest herd of bighorn in the state, numbering more than 700 animals in the late 1970s and early 1980s, the population crashed to around 100 animals or less from 1995 through 2002. It has been growing steadily since.
"The biggest factor in the current growth, I think, is the fires in 2003," said Villepique. "There were two good fires that got a lot of that front country where the sheep live. I think that's the big factor - a lot of that habitat was overgrown."
The lamb-to-ewe ratio was 62 young per 100 ewes, and the highest ratio recorded before this was just more than 50 lambs in 2004. Most years the ratio is between 25 and 35 lambs for each 100 ewes. Villepique called the number of young "really encouraging," especially considering that just five years ago, biologists were concerned the wild sheep population could completely disappear from the San Gabriels.
These surveys have been done almost continuously since 1976.
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