Thermoreuglatory mechanisms in penguins are so much different than any other mammal or bird. Very unique indeed. Have a look how and why.

1. THERMOREGUL
ATORY
ADAPTIONS IN
PENGUINS
Vani Jhaveri

2. Introduction
• Penguins (order Sphenisciformes, family Spheniscidae) are a group of
aquatic, flightless birds living almost exclusively in the Southern
Hemisphere, especially in Antarctica. Highly adapted for life in the water,
penguins have counter shaded dark and white plumage, and their wings
have evolved into flippers. Most penguins feed on krill, fish, squid and
other forms of sea life caught while swimming underwater. They spend
about half of their lives on land and half in the oceans.
• Although all penguin species are native to the Southern Hemisphere,
they are not found only in cold climates, such as Antarctica. In fact, only
a few species of penguin live so far south. Several species are found in the
temperate zone, and one species, the Galápagos penguin, lives near the
equator.

3. Too cold/ Too warm?
• Most common beliefs are that penguins need to find ways to
keep warm rather than cool. But the truth is that when on
land, the problem most penguins face is how to keep cool.
• To survive long in water, warm-blooded animals must be
insulated. Whales have blubber to buffer their body heat from
the body of water that would draw it away. Seals have, as well
as fat, a thick pelt. But birds - birds have no fur and may have
little fat.

4. So how do they do it?
…

5. In the Antarctic's
The internal temperature range of penguins is 37.8°Cto 38.9°C (100°F-102°F).
• FEATHERS: Overlapping feathers create a surface nearly impenetrable to wind
or water. Feathers provide waterproofing critical to penguins' survival in water
that may be as cold as -2.2°C (28°F) in the Antarctic.
• PLUMAGE: The dark plumage of a penguin's dorsal surface absorbs heat
from the Sun, which increases body temperature.
• TRIPOD FORMATION: On land, king and emperor penguins tip up their feet,
and rest their entire weight on their heels and tail, forming a tripod, reducing
contact with the icy surface, and thus reducing heat loss.
• HUDDLING: During storms, emperor penguins huddle together toconserve
heat. As many as 6,000 males will cluster while incubating eggs during the
middle of the Antarctic winter

6. Feathers
[Also note: Tuckingof headto cover
unfeathered areas of face to
conserve heat.]

7. Plumage

8. Resting on heels

9. Huddling

10. In the Antarctic’s
• RESPIRATORY HEAT EXCHANGE SYSTEM: Emperor penguins are able to
recapture 80% of heat escaping in their breath through a complex heat
exchange system in their nasal passages.
• CIRCULATORY HEAT EXCHANGE SYSTEM: To conserve heat, blood flowing to
the flippers and legs transfers its heat to blood returning to the heart.
This countercurrentheat exchange helps ensure that heat remains in the body.
• MOULTING: During the moult, feathers lose some of their insulating and
waterproofing capabilities, and penguins stay out of the water until their
plumage is restored to optimal condition. Penguins fast when moulting. Prior to
this, they each build up a thick layer of fat to provide energy until the moult is
complete.

11. Moulting

12. In the Antarctic’s
FEWOTHERMETHODS:
• To conserve heat, penguins may tuck in their flippers close to
their bodies. They also may shiver to generate additional heat.
• A well-defined fat layer improves insulation in cold water, but
is not enough to keep body temperature stable at sea for long.
Thus penguins must remain active while in water to generate
body heat.

13. In the temperate and tropical regions
• NESTING: In temperateregions, penguins (like Yellow-eyed penguin) avoid
over heating by building nests in forest areas, with a good overhead cover of
vegetation, providing sufficient shade. In tropical regions, penguins seek shelter
from the sun by nesting in burrows or caves.
• FLIPPERS AND FEET: Flippers and the bare feet of penguins that act chiefly as
heat radiators. The feathers on the flippers of all penguins are extremely short
and provide only modest insulation.
• PANTING: Hyperventilating evaporates body water using up body heat as it
does so. Adélie penguins and Yellow-eyed penguins have a circadian rhythm to
their panting: it occurs just after mid-day during the hottest part of the day.
• RUFFLING:Penguins can ruffle their feathers to break up the insulating layer
of air next to the skin and release heat.
• UNFEATHEREDFACE: The faces of many penguins have unfeathered areas to
help dissipate heat.

14. Nesting under forest cover

15. Nesting in caves

16. Extension of flippers

17. Panting

18. In the temperate and tropical regions
FEWOTHER METHODS:
• Little Blue penguin breeding around the coasts of New Zealand
and Australia, go one step further and are active on land mainly
at night, usually coming ashore only after sundown.
• Humboldt penguins, found on the coast of Peru and Chile, dig
burrows in their own guano: their food eventually recycled as
shelter.
• At the equator, the Galapagos penguin, avoids the sun by nesting
in cracks in the lava rock derived from their islands' volcanic
origins.

19. Penguin Chicks
• Chicks can also be in danger of overheating as on calm days their down is even
more efficient at retaining heat than the feathers of their fathers or mothers.
• The down on the chicks' flippers is not as transparent to heat as the flippers of
an adult, and they rely more on their disproportionately large feet to act as
radiators.
• On hot days they lie, flippers spread-eagled at their sides, feet exposed.
• Yellow-eyed penguin chicks may even seek out marshy ground and stand with
their feet in water.
• Parents of those penguins that breed in the open, shade their young chicks by
standing over them.
• As the chicks get older, they are able to regulate their own temperatures and
they may move away from the nest.

20. Parent keeping
chick warm

21. Chick avoiding heat stress

22. Conclusion
• Penguins are endothermic flightless birds who have adapted quite well to
the cold temperatures of the south pole!
• They have special physiological and structural modifications which help
them adjust to the changing temperatures whether on land, or at sea.
• They are not only found in the cold regions of the earth but also in few
warmer regions like temperate, tropical and equatorial regions.
• For these regions, there are a few other modifications to help retain the
cold and not get affected by heat stress.
• Climatic changes are one of the major factors causing deaths in penguins
of all age groups, and thus measures should be taken to conserve these
beautiful creatures!

23. Galapagos Penguins
Humboldt Penguins

24. Yellow-eyedPenguin
Little blue Penguin

25. Emperor Penguin King Penguin

26. Thank You!!!