ADAPTATIONS OF SELECTED
AFRICAN and AUSTRALIAN ANIMALS

PAUL H. YANCEY
PROFESSOR OF BIOLOGY, WHITMAN COLLEGE (Click here for home page)

From trips to South Africa and Botswana, Aug. 2001, and Australia, Jan. 2003

See also these webpages: ANIMALS of ICELAND (June 2010 trip); ANIMALS of NEW ZEALAND (1998 and 2012 trips); and
ANIMALS of the AMERICAS in COSTA RICA, AMAZON, TURKS & CAICOS, YUCATAN
(trips to Manaus region, Brazil Aug. 2004; Costa Rica Nov. 2008; Turks & Caicos Nov. 2009; Yucatan Sept. 2010)

GO TO Prof. Yancey's Home Page

GO TO Prof. Yancey's DEEP-SEA Educational Site

GO TO Whitman Biology Home Page

I am an animal physiologist, mainly researching the adaptations of marine animals. I also did a brief physiological study on possums in New Zealand in 1994. In 2001 I attended an international animal physiology conference in Botswana. In Jan. 2003 I went to Victoria and Tasmania, Australia, to attend another international physiology conference. We saw incredible animals at very close range (on safaris in South Africa, Botswana, Zimbabwe, and wild animal parks in Tasmania). Here I present some of the interesting physiological and anatomical adaptations, especially new findings, on some of the wonderful creatures of those two continents. I also have links to selected websites with more details.

If you copy and use photos, please WRITE for PERMISSION first at yancey -AT- whitman.edu). All of these photos are mine. However I cannot give permission for use of any information and pictures from the other websites that I've linked to.

I. AFRICA: Animals from Botswana and South Africa (click on pictures for larger versions)

Elephants and Water
Elephants have long been known to make use of water beyond simple drinking. Recent findings (1999-2002) suggest that elephants evolved from a fully aquatic ancestor. Dr.John West has found that they have lung structures reinforced for the pressures of snorkeling and diving, and Dr. Ann Gaeth has found that their fetal kidneys go through a stage like that of aquatic animals. Click the blue links for more.
In Chobe Nat'l Park, Bostwana, we enjoyed seeing elephants drinking in the Zambezi River (left). We were even more thrilled to see elephants in the river using their trunks like snorkels right in front of our tour boat!(see pictures to right).

 

Elephants and Ground Sound
Elephants make a number of sounds involved in communication. They also have large ears (left, an elephant crossing the road in front of us in Kruger Nat'l Park, S. Africa). These ought to be great for hearing (as well as providing a high surface area for radiating excess body heat). New research (2002) by Dr. Caitlin O'Connell-Rodwell reveals that their FEET may be adapted for picking up seismic waves in the ground.They may be listening to the stomps of other elephants, and distant storms, floods, and stampedes.

 

Giraffes and Blood Pressure
In Chobe, we saw giraffes leaning down to drink or eat. Modern medicine is concerned about high blood pressure in humans, but a giraffe routinely has blood pressures (200 mm Hg) well above the danger level for humans. It needs this in order to overcome gravity when pumping blood to the head. But what happens when the animal lowers its head to drink? Wouldn't the blood pressure rise even more in the head and cause brain damage? The animal may partially reduce the problem by lowering its front legs (see pictures), thus reducing the height of the heart above the head. But it also has special blood vessels, valves and sensors to reduce the problem even further. Read about them at Wildwatch.

 

The Heart of a Crocodile
Crocodiles breathe air, but they can submerge for hours while waiting for prey. Craig Franklin and Michael Axelsson (2000) found that the estuarine crocodile Crocodylus porosus has unique cog-like valves that control blood flow between the lungs and the rest of the body. When the animal is submerged, these valves divert blood leaving the heart away from the lungs (where blood is not needed) and straight back to the main body.
Left: a croc in the St. Lucia estuary, S. Africa. Right: in the Zambezi river, Chobe Nat'l Park, Botswana. In both cases we saw these animals just a few meters from our boat.

 

Hippos: Cousins of Whales
Several recent studies indicate that whales evolved from an ancestor closely related to hippopotami. DNA analysis [Adobe Acrobat Reader needed to access this link] by Bjorn Ursing and Ulfur Arnason (1998; following up earlier research by Arnason and colleagues) suggest that hippos are whales' closest land-dwelling relatives still in existence. New fossil evidence--a terrestrial ancestor of whales found in Pakistan in 2001 by Philip Gingerich and colleagues--supports this conclusion. However, there is conflicting evidence.
Left: a hippo in Chobe Nat'l Park, Botswana. Right: huddling hippos in the St. Lucia estuary (S. Africa) close to our boat.

 

The BLACK RHINOCEROS: mother and baby (right). This pair passed close to our jeep in the Hluhluwe Reserve in S. Africa. They are beginning to thrive is S. Africa after nearing extinction due to poaching; their horns are prized by some Asian cultures for their supposed aphrodisiac qualities (for which there is NO evidence!). Read more about rhinoceros species at exZOOberance.

The SPOTTED HYENA (right). Hyenas are of great interest to physiologists because the females are masculinized, with male-like genitals and aggressive behavior. Read about research on male and female brains in 1999. Read about their general biology at The Hyena Pages.

 

Here are some other fascinating animals for which I've found minimal physiological research.
If you are aware of any such recent research, email me (yancey-AT-whitman.edu)

The CAPE BUFFALO (right). In our jeep, our driver took us to within a few feet of this dangerous animal. Read more about this animal in the Cape Buffalo Wikipedia entry.

The BANDED MONGOOSE (right), in Chobe Nat'l Park, Botswana. Read more about them at Animal Diversity Web, Univ. Michigan.

 

<--The MALACHITE KINGFISHER. This bird likes to perch on branches over the water, looking for aquatic prey. Our river guide in the St. Lucia estuary (S. Africa) took us to within a few feet of this bird on the tour boat. For information on this beautiful bird, see the Safaricam encylopedia website.

<--The beautiful SABLE ANTELOPE, staring at us in our jeep in Chobe Nat'l Park, Botswana. For information on the biology and conservation of this magnificent animal, see the Sable Antelope Website

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II. AUSTRALIA: animals we saw in southern Australia (Melbourne and Tasmania). Click on pictures for larger versions. There is much information on the web about most of these animals. Try in particular the Unique Australian Animals Site and the Tasmanian Parks & Wildlife Site.

A. MONOTREMES: These are mammals that lay eggs! Only two still exist--the platypus and the spiny echidna. Their body temperatures are somewhat lower than ours, but they do thermoregulate, have hair, and nurse their young like other mammals.

PLATYPUS--An Electricity Detector. Seen here in the Melbourne zoo (this is a stuffed one! The live ones are in a very dim nocturnal habitat where no pictures can be taken).A truly bizarre and endearing creature that swims in streams and ponds using electrical sensors in its duckbill to find prey hidden in the stream bed. The male has poisons spikes on its rear webbed feet. Find out more at Platypus Physiology Website1 and Website2, and broader information at the Unique Australian Animals Site and the Tasmanian Parks & Wildlife Site.

 

ECHIDNA--An Erectile Snout. Also called "spiny anteaters," they do eat insects with their tiny sensitive snouts.One recent physiological study found that the echidna's snout has a special "push-rod" tissue that inflates the snout for poking into termite mounds and ant nests. Inflation also greatly enhancing snout sensitivity. Researchers note that this process is very similar to what happens in erectile genitalia.
In Tasmania, we saw wild ones all over (often as "road kill," unfortunately.) One we stopped for on a mountain road, and watched as it waddled a meter or so onto the road, rolled up into a ball with its spines up for protection, then a few seconds later waddled a bit and rolled up again--took about 4 cycles to make the crossing!

Find out more about at the Henry's Echidna website, which has lots of links; and the Unique Australian Animals Site and the Tasmanian Parks & Wildlife Site.

B. MARSUPIALS: these are also mammals; they give birth to very tiny live young which then crawl to a pouch on the mother's abdomen to be suckled.These pictures are mostly from Tasmania, with a couple from the Melbourne zoo. Some give birth to many more offspring that they can nourish, so that a "survival of the fittest" struggle occurs among the newborns as they race and fight for the few teats in the pouch. For example, the Tasmanian devil may give birth to several dozen babies, which struggle for only 4 teats.

KANGAROO--An Efficient Mover. There are vast amounts of information on the web about these famous animals Try the Australian Wildlife 'Roo page, or ExZOOberance. One interesting physiological trait is that 'roos actually use LESS energy as their hopping speed increases! (Except at highest speeds). The secret is probably in the huge tendons in its hind limbs. These act as springs, storing energy when they hit the ground, releasing it on the next hop, and doing so more efficiently at higher speeds. A hop at medium speed also covers a larger distance than at low speed. Overall the distance covered per unit of metabolic energy (like "miles per gallon") improves at moderate compared to low speeds, unlike any other form of locomotion (except gliding by birds in flight).

SUGAR GLIDER (Tasmania). This marsupial has thin membranes between its fore- and hindlimbs, allowing it to glide from tree to tree. They also like sweet tree sap.See the Unique Australian Animals Site and the Tasmanian Parks & Wildlife Site.

 

TASMANIAN DEVIL: Super Stomach. An eater of carcasses, a pack of devils may eat every part of a dead animal including bones, using powerful jaws. They also hunt small live prey. They are only found in Tasmania today; we saw several wild ones while driving. Alarmingly, many are now dying due to Facial Tumor Disease. Click this link for more information. See more on the biology of these animals at Unique Australian Animals Site and the Tasmanian Parks & Wildlife Site.

 

Golden POSSUM (Tasmania) . Not the same as the American possum! This may be a variant of the common brush-tailed possum of Australia. Because of their nice pelts, the latter was introduced by Europeans into New Zealand, which had no native mammals except bats. The possum in New Zealand has no natural predators, and has wreaked havoc with that island nation's ecology.

Common WOMBAT (Tasmania)--Evolved for Burrowing. These have a hard plate over their lower backs to protect them from predators when they are burrowing. Its pouch faces backwards, to keep dirt out while burrowing. See Tasmanian Parks & Wildlife page--with movies!

 

KOALA--The Ultimate "Couch Potato*." An eater of eucalyptus leaves, this animal spends 80-90% of its time sleeping (as in the far left picture)! Often they are clinging to small branches, and yet sleep without falling. There is considerable information on the web on this endearing animal. Try this KOALA Website as a fine example, or the Unique Australian Animals website. Pictures here from Tasmania.

*a term for a person who sits around all day watching TV from a couch...

I don't have any anatomical or physiological information on these two interesting marsupials:

SPOTTED-TAIL QUOLL, or TIGER CAT (Tasmania). A large meat-eater of eastern Australian forests. See the Quoll Website for information.

Long-Nose BANDICOOT (Tasmania). These rare hopping marsupials are almost extinct, in part due to killing by foxes deliberately introduced into Australia by hunters.See the Unique Australian Animals Site and the Tasmanian Parks & Wildlife Site.


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