Bighorn Sheep Ecosystem Dynamics

The video explores the history and challenges of North American sheep, focusing on the Sierra bighorn sheep. It discusses the impact of human activities and grazing on ecosystems, leading to habitat changes and increased predation by mountain lions. Archaeological studies provide insights into past ecosystems, revealing how grazing has transformed grasslands into sagebrush steppes, affecting the survival of bighorn sheep.

What event led to the separation of sheep into two distinct populations in North America?

• The arrival of European settlers

• The last glaciation

• The crossing of the Bering Land Bridge

• The introduction of domestic livestock

What factor contributed to the decline of Sierra bighorn sheep populations in the 1980s?

• Increased hunting by humans

• Introduction of invasive plant species

• High levels of mountain lion predation

• Severe drought conditions

What was the primary focus of Robert Bettinger's archaeological studies?

• The impact of climate change on ecosystems

• The spread of culture in Western North America

• The migration patterns of bighorn sheep

• The introduction of domestic livestock

What was the dominant prey species in the highland archaeological record?

• Mountain sheep

• Mountain lions

• Bison

• Deer

What major change in vegetation occurred due to grazing by domestic livestock?

• Desertification of the region

• Expansion of grasslands

• Transformation to sagebrush steppes

• Increase in forested areas

What was the primary cause of the transformation from grasslands to sagebrush steppes?

• Natural forest fires

• Climate change

• Grazing by cows and sheep

• Invasive plant species

What role do mountain lions play in the altered ecosystem?

• They have no significant impact

• They primarily prey on bighorn sheep

• They are dependent on deer populations

• They help control invasive plant species

What is the current status of bighorn sheep in their historical ranges?

• They are clinging to existence

• They are thriving and expanding

• They are extinct in the wild

• They have migrated to new areas

What is a significant consequence of the introduction of deer into the ecosystem?

• Decline in mountain lion populations

• Restoration of grassland habitats

• Increased competition for food with bighorn sheep

• Stabilization of the ecosystem

What must humans do to help protect the remaining bighorn sheep populations?

• Reduce grazing by domestic livestock

• Reintroduce mountain lions

• Restore grassland habitats

• Increase hunting of deer