¹ Removal of animals from the population (functional mortality, if not actual mortality). ² Tortoises are expected to be adapted to drought, but it may make them more susceptible to other stressors.³ Coyotes may increase predation on tortoises as preferred prey become less common.⁴ That grasses are less nutritious than forbs is well established, but the effects of introduced grasses on tortoise habitat quality and population size is less well studied.⁵ Increased raven numbers and increased risk of raven predation are well-established. Consequences of raven predation to tortoise population size are less well-studied.⁶ Few mortalities observed, but damage to styrofoam tortoise models indicates rates can be high.⁷ Rates of burrow damage depended on tortoise size, with juvenile and immature burrows more susceptible to damage than adult burrows.⁸ Changes in soils and in vegetation structure and composition.⁹ Largely unstudied as a group, though several possible activities (such as target shooting) are included in other categories.¹⁰ Transmission towers may facilitate raven population growth in areas previously lacking nesting substrates.¹¹ That tortoises are killed is well supported, but the population-level consequences are not known.