User:Cbutl37/sandbox

Adaptations
The average hematocrit level for birds is between 30 to 45%; however, the Amethyst Sunbird has an average hematocrit level of 50%. Amethyst sunbirds can be found along an altitudinal gradient in South Africa from the Drakensberg mountain range to the coast of KwaZulu-Natal. During warmer months, the sunbird's hematocrit levels will increase with higher altitudes (dramatic drop in temperature) and with less oxygen concentration in the atmosphere. Higher hematocrit levels may be attributed to small body size and can help with oxygen carry capacity and the metabolic cost of flying.

Subpopulations of Amethyst Sunbirds show variation in their resting metabolic rates, basal metabolic rate, and thermal neutral zones based on the subpopulation's acclimation to different altitudes. Those more acclimated to high altitudes would have a lower metabolic rates and a larger thermal neutral zone. The phenotype of these birds includes a huge range between multiple different subpopulations showing increase endurance to changes in climate. The Amethyst Sunbird can change its tolerance to altitude temperature to better aid their metabolic rate and internal heat regulation.