IUCN / SSC Cat Specialist Group - Digital Cat Library |
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| Laundr‚, J.W.; Hern ndez, L.; Ar¡as del Razo, I.; Fowles, G. | |
| The landscape of fear and its implications to sheep reintroductions | |
| 2002 Conference Proceeding | |
The record for bighorn sheep (_Ovis canadensis_) reintroductions is not stellar; recent analyses indicate a less than 50% success rate. Most models to evaluate potential release sites center on assessing the amount of "escape habitat" available. Escape habitat has been defined as steep, rocky areas where sheep can outmaneuver their predators. This may be a good definition for predators that chase their prey such as coyotes (_Canis latrans_) or even wolves (_C. lupus_). However, in most areas of sheep reintroductions, the main predator is the puma (_Puma concolor_). Pumas stalk their prey and the definition of escape habitat overlaps substantially with what definitions of excellent hunting habitat for pumas. This indicates that a possible reassessment of escape habitat, especially in reference to sheep reintroductions, might be warranted. Many studies have shown that vigilance behavior is a good indicator of predation risk. Based on this, we are assessing predation risk of different habitat types relative to vigilance levels sheep exhibit. We are conducting this study in southern Idaho on a newly reintroduced California Bighorn Sheep (_O. c. californiana) _population that is preyed on by pumas. We monitored vigilance (head up and alert) of sheep for 20 minute time blocks in different habitat types, e.g. rock, cliff, open grass, etc. We found significantly higher vigilance rates in rocky (32.3 + 3.1 % ) and cliff habitats (30.1+ 4.5%) than in sage (16.7 + 1.8%) and grass/sage (22.1 + 2.8 %) areas. Our data indicate sheep perceive defined escape habitat as highly risky while open grass slopes as relatively safe. Results of our final analysis should help us assess the landscape of fear for sheep relative to puma predation and provide a more realistic assessment of potential release sites. |
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