Age-specific moose (Alces alces) mortality in a predator-free environment:Evidence for senescence in females

We tested whether the ungulate moose (Alces a[ces) showed senescence in sur vival. Senescence, i.e., a progressive deterioration with age, may be obscu red by multiple mortality causes in a wild population. Thus, we followed ra dio-marked individuals of known age to separate different mortality causes in adult moose. The risk of dying of causes not linked to humans increased with age. For females, the increase in natural mortality was first observab le after age 10. Tooth wear was significantly related to age Lbr both sexes , but was stronger for males. It suggests that males would experience senes cence in survival earlier than females in a non-hunted population The senes cence in mortality observed for female moose may be a result of delayed cos t of reproduction acting in concert with tooth wear due to a reduced abilit y to process food. We also found an increase in hunting mortality with age for both sexes, with males facing a higher risk of dying than females. The age-related hunting mortality may be ii result of selectivity by the human predator, or a change in moose behaviour with age.