Prey depletion, interspecific competition, and the energetics of hunting in endangered African wild dogs, .

Large herbivores are in decline in much of the world, including sub-Saharan Africa, and true apex carnivores like the lion () decline in parallel with their prey. As a consequence, competitively subordinate carnivores like the African wild dog () are simultaneously experiencing a costly reduction in resources and a beneficial reduction in dominant competitors. The net effect is not intuitively obvious, but wild dogs' density, survival, and reproduction are all low in areas that are strongly affected by prey depletion.

Spatial Risk Effects From Lions Compound Impacts of Prey Depletion on African Wild Dogs.

Prey depletion threatens many carnivore species across the world and can especially threaten low-density subordinate competitors, particularly if subordinates are limited to low densities by their dominant competitors. Understanding the mechanisms that drive responses of carnivore density to prey depletion is not only crucial for conservation but also elucidates the balance between top-down and bottom-up limitations within the large carnivore guild. To avoid predation, competitively subordinate African wild dogs typically avoid their dominant competitors (lions) and the prey rich areas they are associated with, but no prior research has tested whether this pattern persists in ecosystems with anthropogenically-reduced prey density, and reduced lion density as a result.

Pulmonary vasoconstriction in steers at high altitude.

Each of ten steers taken for 9 weeks to 12,700 ft. (Mt. Evans, Colorado) showed a marked increase in pulmonary artery (PA) pressure.