| potential mortality effects of off-highway vehicles on the flat-tailed horned lizard (phrynosoma mcallii): a manipulative experiment. | southern california desert public lands receive especially high levels of off-highway recreation due to large population centers nearby and popular riding environments such as sand dunes. controversy has developed over the flat-tailed horned lizard (phrynosoma mcallii), previously a candidate for listing under the endangered species act. some evidence suggests lower lizard abundance in areas of higher recreational use than in areas with low or no use. we designed a manipulative experiment to ens ... | 2009 | 18941830 |