Blood flow distribution during forced and voluntary diving in ducks, and the energetic cost of diving was investigated.
It has been suggested that in order for the leg muscles to generate enough power for ducks to dive, blood flow to those tissues must be maintained. A technique to determine blood flow distribution which could be used during voluntary diving was first developed and tested during forced laboratory dives of ducks. This technique was then used to determine the blood flow distribution during voluntary diving. Regional blood flow distribution was visualized by utilizing a radioactive tracer technique (macro aggregated albumin labelled with ⁹⁹ⅿ technetium). The tracer when injected into an animal is trapped and held by capillaries. During forced dives in dabbling (Anas platyrhynchos) and diving (Aythya affinis) ducks the blood flow distribution was found to be restricted to the thoracic and head areas. Whereas during a voluntary dive in A. affinis blood flow distribution was shown to be preferentially directed towards three tissue areas, the heart, brain, and active leg muscles.
The work required to dive was determined from the measurement of subsurface drag forces and buoyancy in A. affinis. Subsurface drag increased as a nonlinear function of swimming velocity. At a velocity of 1 m•s⁻¹, the drag force was approximately 1.067 N. The average measured buoyant force of 11 ducks was 0.953 N. The calculated mechanical work done by ducks during a 14.4 s unrestrained dive was 9.34 J. The power output during voluntary was estimated to be 0.751 W (0.0374 ml 0₂•s⁻¹). During diving buoyancy is clearly the dominant force (8.8 J) against which ducks have to work while drag (0.54 J) adds little (~6%) to the energetic cost of diving. / Science, Faculty of / Zoology, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/26417 |
| Date | January 1987 |
| Creators | Heieis, Mark Rudolf Alois |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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