Table of Contents
How do penguins prevent conduction?
Like all birds penguins rearrange their feathers by preening. 2/ To retain heat, penguins may tuck in their flippers close to their bodies, this reduces the surface area available for heat loss.
Why is counter current better?
One of the great advantages of counter-current flow is the possibility of extracting a higher proportion of the heat content of the heating fluid. It is important to note that the LMTD value for counter-current flow is much larger than for cocurrent flow at the same terminal temperature (see Figure 1.9).
How do birds not freeze?
Many birds have no feathers on their legs and feet, but instead allow their feet to reduce in temperature to align almost exactly with the temperature of whatever they are stood on. Birds avoid freezing to death via their little feet by a system known as counter-current exchange.
How do birds regulate water balance?
Birds utilize three organs or organ systems to maintain homeostasis of total body water: kidneys, lower gastrointestinal tract, and nasal or orbital salt glands. The kidneys by themselves do not conserve large amounts of water by elaborating urines that are significantly more concentrated than the plasma.
How do penguins use radiation?
The penguins do lose internal body heat to the surrounding air through thermal radiation, just as our bodies do on a cold day. Because their bodies (but not surface plumage) are warmer than the surrounding air, heat gradually radiates outward over time, moving from a warmer material to a colder one.
How do penguins use convection?
While penguins lose some of their heat through their insulating plumage layer, keeping their feathers cooler enables them to gain a slight amount of energy back through thermal convection. Thermal convection is the process of transferring heat through the motion of fluids.
Why is countercurrent exchange more efficient?
Counter Flow Heat Exchanger This distributes the heat more evenly across the heat exchanger and allows for maximum efficiency. In theory, the cold fluid can exit the heat exchanger at a higher temperature than the temperature of the hot fluid outlet, although in reality this is very difficult to achieve.
How do birds eliminate waste?
Birds, unlike mammals, do not have separate exits for urine and feces. Both waste products are eliminated simultaneously through the cloaca. While mammals excrete nitrogenous wastes mostly in the form of urea, birds convert it to uric acid or guanine, which reduces water loss in comparison.
How do penguins protect themselves from heat loss?
Thick plumage has excellent insulation and only unfeathered regions (feet, eye and bill) and sparsely feathered flippers showed heat loss from the body interior. Heat loss in penguins is minimized by counter-current heat exchange systems through arterio-venous networks in the head, axillae and legs.
What is the thermal conductivity of a penguin?
Penguin plumage has a low thermal conductivity [ 22] and even with strong solar warming changes in avian skin temperature are minimal [ 23, 24 ]. Despite higher flipper and head temperature, their estimated convective heat loss was small.
How do emperor penguins adapt to their environment?
Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling.
Can thermal imaging of emperor penguins be used in Antarctica?
Thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie, Dumont d’Urville, in Terre Adélie (66°40′ S 140° 01′ E), Antarctica from 4 June to 29 June 2008.