The average hematocrit level for birds is between 30 to 45%; however, the Amethyst Sunbird has an average hematocrit level of 50%. [1] Amethyst sunbirds can be found along an altitudinal gradient in South Africa from the Drakensberg mountain range to the coast of KwaZulu-Natal. [2] 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. [3] Higher hematocrit levels may be attributed to small body size and can help with oxygen carry capacity and the metabolic cost of flying. [3]
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. [4] 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. [4]
- ^ Marsen, S. (2009-02-01). "Book review: BARBARA JOHNSTONE, Discourse Analysis, 2nd edn. Oxford: Blackwell, 2008. 312 pp". Discourse Studies. 11 (1): 121–123. doi: 10.1177/1461445608101544. ISSN 1461-4456.
-
^ Yom‐Tov, Yoram (2002-09).
"Sunbirds: A Guide to the Sunbirds, Flowerpeckers, Spiderhunters, and Sugarbirds of the World. By Robert A Cheke and , Clive F Mann; illustrated by , Richard Allen. New Haven (Connecticut): Yale University Press. $50.00. 384 p; ill.; index. ISBN: 0–300– 08940–6. 2001". The Quarterly Review of Biology. 77 (3): 340–341.
doi:
10.1086/345222.
ISSN
0033-5770.
{{ cite journal}}: Check date values in:|date=( help); no-break space character in|title=at position 104 ( help) - ^ a b Lindsay, Claire V.; Downs, Colleen T.; Brown, Mark (2010-04-01). "Seasonal variation in hematocrit levels of Amethyst Sunbirds (Chalcomitra amethystina) over an altitudinal gradient". Journal of Ornithology. 151 (4): 851–855. doi: 10.1007/s10336-010-0522-z. ISSN 0021-8375.
- ^ a b Lindsay, C. V.; Downs, C. T.; Brown, M. (2009-02-15). "Physiological variation in amethyst sunbirds (Chalcomitra amethystina) over an altitudinal gradient in winter". Journal of Experimental Biology. 212 (4): 483–493. doi: 10.1242/jeb.025262. ISSN 0022-0949.
The average hematocrit level for birds is between 30 to 45%; however, the Amethyst Sunbird has an average hematocrit level of 50%. [1] Amethyst sunbirds can be found along an altitudinal gradient in South Africa from the Drakensberg mountain range to the coast of KwaZulu-Natal. [2] 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. [3] Higher hematocrit levels may be attributed to small body size and can help with oxygen carry capacity and the metabolic cost of flying. [3]
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. [4] 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. [4]
- ^ Marsen, S. (2009-02-01). "Book review: BARBARA JOHNSTONE, Discourse Analysis, 2nd edn. Oxford: Blackwell, 2008. 312 pp". Discourse Studies. 11 (1): 121–123. doi: 10.1177/1461445608101544. ISSN 1461-4456.
-
^ Yom‐Tov, Yoram (2002-09).
"Sunbirds: A Guide to the Sunbirds, Flowerpeckers, Spiderhunters, and Sugarbirds of the World. By Robert A Cheke and , Clive F Mann; illustrated by , Richard Allen. New Haven (Connecticut): Yale University Press. $50.00. 384 p; ill.; index. ISBN: 0–300– 08940–6. 2001". The Quarterly Review of Biology. 77 (3): 340–341.
doi:
10.1086/345222.
ISSN
0033-5770.
{{ cite journal}}: Check date values in:|date=( help); no-break space character in|title=at position 104 ( help) - ^ a b Lindsay, Claire V.; Downs, Colleen T.; Brown, Mark (2010-04-01). "Seasonal variation in hematocrit levels of Amethyst Sunbirds (Chalcomitra amethystina) over an altitudinal gradient". Journal of Ornithology. 151 (4): 851–855. doi: 10.1007/s10336-010-0522-z. ISSN 0021-8375.
- ^ a b Lindsay, C. V.; Downs, C. T.; Brown, M. (2009-02-15). "Physiological variation in amethyst sunbirds (Chalcomitra amethystina) over an altitudinal gradient in winter". Journal of Experimental Biology. 212 (4): 483–493. doi: 10.1242/jeb.025262. ISSN 0022-0949.