Download Background information on the question: “Do Pandas

Background information on the question: “Do
Pandas Really Exist? “
There are two animals that are called “pandas”,
the giant panda (Ailuropoda melanoleuca) and
the red (or lesser) panda (Ailurus fulgens). In
1825, Frederick Cuvier first described the red
panda for western science. The giant panda was
discovered and described in 1869 by Père David.
Figure 2. Ailurus fulgens.
From ARKive.org (2004).
Figure 1. Ailuropoda melanoleuca.
From baldeagleinfo.com (2005)
When scientists discover and describe a new species, the first thing
they do is give it a two-part scientific name and try to classify it into
a group of its closest relatives. However, soon after these two species were discovered,
scientists argued about what a panda is. Some scientists thought that both pandas are most
closely related to members of the raccoon family (option 1). Others thought that the red panda
is part of the raccoon family and the giant panda is part of the bear family (option 2). And yet
others thought that the two pandas belonged together in a separate panda family (option 3).
When this controversy started, scientists were limited in the type of information they could use
to answer this type of question. Because they didn’t yet know much about proteins and DNA,
they certainly could not use them to help answer these questions. Therefore, they had to rely on
other types of information like biogeography (where organisms live), fossils, behavior, and
morphology (how the animals are built). Here is some of the information they had to work with:
Figure 3. Example members of the raccoon
family (procyonidae): the northern
raccoon(NPS.gov, 2004) and the coatimundi
(Braddy, S. 2003).
Figure 4. Example members of the bear family
(ursidae): the sun bear (Bies, 2002) and the
grizzly bear (Ballenger and Dewey,2002).
?
?
Figure 5. Giant (baldeagleinfo.com, 2005) and
red pandas (ARKive.org, 2004)
Biogeography.
Both of these animals live in China’s southwestern bamboo forests (Figures 6 and 7). The six
bear species are found in Europe, Asia, and the New World (Figure 8). Except for the red
panda, all of the other members of the raccoon family live in the New World (the
Americas)(Figure 9). (Distribution maps based on Nowak, 1991.)
Figure 6. Giant Panda range
Ailuropoda melanoleuca
Figure 7. Red Panda
range Ailurus fulgens
Figure 8. Worldwide bear
(ursidae) distributions.
Figure 9. Worldwide
raccoon family (procyonid)
distribution
Fossils. Fossil raccoons first appear in North
America and spread to Asia and Europe about 20
million years ago. Panda fossils (from about 12
million years ago) first appeared in Europe and
North America. They are similar to a group of small
bear fossils (that are all now extinct).
Figure 10. Movement of the continents over time
(CDSP, 2003)
Behavior.
The red panda feeds on bamboo sprouts, other plant material, and the occasional small animal.
The giant panda feeds mostly on bamboo, but also eats other vegetation and occasionally hunts
fish and small mammals. Unlike bears, the giant panda marks its territory using scent glands something that the red panda and the members of the raccoon family also do (Nowak, 1991).
Morphology.
Like other bears, the giant panda gives birth to very tiny offspring that grow into very large
adults. The adult bears are 100s of times larger than the newborns. On the other hand, the red
panda and members of the raccoon family give birth to newborns that are about 50 times
smaller than the adults (Nowak, 1991).
Both species have skulls, teeth, and forepaws that are specially adapted to eating bamboo. The
table below presents information on the weights, skull lengths and dental formulas for some
representative members of the raccoon and bear families and the two panda species.
Table 1. Morphological characteristics.
Species
Family
Raccoon
(Procyon lotor)
Raccoon
Weight
(kg)
(Nowak,
1991).
6
Coatimundi
(Nasua narica)
Raccoon
4.5
13
Grizzly Bear
(Ursus arctos)
Bear
450
49.5
Sun Bear
(Ursus malayanus)
Bear
46
22
Red Panda
(Ailurus fulgens)
?
5
11.5
Giant Panda
(Ailuropoda melanoleuca)
?
100
26.5
Additionally, the giant panda has a wrist
bone that sticks out like a thumb to help
it grip the bamboo. This wrist bone
(sometimes called a pandas “thumb”) is
used to strip the leaves off of the
bamboo (Morris and Morris, 2000). That
way, the panda is left with only the
nutritious bamboo shoot.
Skull Length (cm)
skullsunlimited.com
(2005)
12
Figure 11. Sesamoid bone
of the giant panda (Morris
and Morris, 2000).
Dental Formula
skullsunlimited.com (2005)
I
3 1 4 2
C P M = x 2 =40
3 1 4 2
I
3 1 4 2
C P M = x 2 =40
3 1 4 2
I
3 1 4 2
C P M = x 2 =42
3 1 4 3
I
3 1 4 2
C P M = x 2 =42
3 1 4 3
I
3 1 3 2
C P M = x 2 =38
3 1 4 2
I
3 1 4 2
C P M = x 2 =42
3 1 4 3
Figure 12. Comparison of the
sesamoid bones of a grizzly
anda a giant panda (Morris
and Morris, 2000).