Bighorn on the Greens - Spring 2015
We hear stories throughout the year about bighorn sheep sightings on four golf courses in La Quinta (Tradition, SilverRock, PGA West and The Quarry). Most people are excited to see the sheep and some mistakenly think that the sheep need these urban areas, especially during the drought. We understand this concern, but hope readers will realize that it is not good for the bighorn to be down in the urban areas; the sheep do not need the golf courses. They need to be in the wild where they survive best.
We know this because we conducted two previous mortality studies on an adjacent herd of bighorn sheep. They regularly utilized the urban areas of Rancho Mirage since the 1950s, when Thunderbird estates was built in an alluvial fan used by the sheep. We found that 34% of the adult bighorn and 43% of the lambs died from the effects of urbanization during our studies. The sheep were killed by auto collisions, non-native toxic plant ingestion (oleander), wire entanglement, and drowning in swimming pools. In addition, we found strongyle intestinal parasites in 86% of the adult bighorn tested during our study. These parasites typically do not persist in the dry desert, but thrive on watered lawns. Our research findings led the City of Rancho Mirage to voluntarily put up a bighorn exclusion fence. Completed in 2002, this 4 mile, 8 feet high chain-link fence has eliminated urban-related bighorn deaths in the Rancho Mirage area and promoted recovery for this endangered species. Since the fence was finished, 12 years ago, the bighorn population has increased, in fact, this herd reached its recovery goal of 25 ewes just 2 years after the fence was completed. Lamb recruitment (survival) has doubled, the number of deaths has significantly decreased and the sheep have shifted their habitat use away from the urban setting and are utilizing historic habitat.