Lauren Beal
Environmental Science
Habitat Fragmentation: Varying Effects on Two Species
The giant panda of China and the North American coyote are faced with a similar
situation; their respective habitats are being destroyed or changed into smaller, isolated
fragments. The effects of habitat destruction on the two species, however, are vastly
different. Once found primarily in the northwest region of the United States, the coyote
has adapted readily to changes caused by humans and has been steadily extending its
range. The coyote can be found throughout the North American continent, extending
from eastern Alaska to New England, and south through Mexico and Panama. It has even
been sighted in urban
areas. In contrast, the
giant panda population
has been steadily
diminishing along with
its respective habitat. Its
population originally
extended through the mountains of most of southern and eastern China and northern
Vietnam, but by 1900, the area has been reduced to the Qinling Mountains. This area
was further reduced as agricultural expansion broke it into separate regions in six
mountain ranges. These isolated regions within six mountain ranges in China are the
only places in nature that pandas can be found today. A recent report by the World
Wildlife Fund stated the panda habitat has shrunk by 50 per cent in China’s Sichuan
Province, home to the largest natural population of giant pandas (www.ecoworld.com).
Why does a loss of habitat result in such a marked difference in the population of
these two species? The answer lies in biological factors and adaptability. This paper will
attempt to compare and contrast the major characteristics of each species, showing the
relationship between these characteristics and population growth/decline. In addition, it
will address possible human impact and interventions.
Giant Panda
It is easy to get a mental picture of a giant panda; the characteristic white and
black markings, bear-like face and round body distinguish it from other animals. Pandas
are large animals, ranging in size from 63 to 75 inches and weighing in between 150 -275
lbs (depending on gender). Pandas fit the defining characteristics of a K-selected, or
equilibrium, species. Female pandas carry their young for approximately 135 days, and
only one or two panda cubs are born to a mother each year. Young pandas are entirely
dependent on the mother until they are weaned at about
nine months; they leave their mothers when she
conceives again, when they are about 18 months of age
(www.animalinfo.org).
Pandas are usually solitary creatures, though
their home ranges can overlap with one another. They come together during mating
season, which stretches from mid-March to mid-May. It is a well-known rumor that
pandas have trouble reproducing; this may not be as true as we have come to believe. A
World Wildlife Fund study reports “research shows that the giant panda may live longer
in captivity, but that breeding success is greater in the wild” (www.ecoworld.com). Wild
panda populations involved in long-term studies have shown to have reproductive rates
similar to the thriving American black bears (Pandas –Ecology).
Pandas consist almost entirely on a diet of bamboo, a plant that grows abundantly
in the mountain ranges of China. Pandas are specialists; they have evolved with
adaptations that aid in the process of eating and digesting bamboo and are, for the most
part, restricted to this food source. Pandas might look like their bear relatives, but they
are herbivores with flat, ridged teeth designed for crushing and grinding bamboo. Their
strong jaws and cheek muscles help them chew the thick stalks. They have a moveable
wrist bone that acts like a thumb, allowing the pandas to better grasp bamboo. Pandas’
digestive tracts are similar to carnivores, meaning they have trouble digesting the
cellulose of bamboo. This leads to a need to consume large amounts of bamboo to
sustain them.
Bamboo is abundant in the rainy forest habitat of the pandas, and grows
throughout the year. Pandas eat all parts of the bamboo plant, from its tough stalk to its
leaves. Because bamboo is so low in nutrients, pandas spend nearly 10 to 12 hours
feeding per day, and eat up to 80 pounds of bamboo in just one day. Bamboo plants grow
to maturity, flower and produce seeds, and then die. The seeds slowly grow into large
plants. While bamboo is abundant in the forest, it goes through dying periods, where all
of the species in one area will bloom and die at the same time. This forces the pandas to
migrate to another area to find more bamboo; as habitat fragmentation becomes more of
an issue, it is increasingly difficult for pandas to migrate to other areas. Pandas are not
restricted to one species of bamboo – they can eat 25 different types – but they usually
eat only the few types that grow in their home range. (www.animalinfo.org).
Coyotes
A member of the dog family, the coyote is similar in shape and size to a collie.
Coyotes can range from 20 to 50 pounds in weight, depending on where they live. The
animals have a round, bushy tail that they carry straight out below their backs.
High elevation coyotes have dark, thick, long hair with a white underbelly that becomes
long and silky in the winter months. The animals have five digits on their forefeet and
four on their hind feet, and walk with only their toes touching the ground. Coyotes are
swift runners and can easily leap an average of eight feet. While still considered a Kselected species, coyotes are further along the continuum toward r-selected species than
the giant panda because of a higher number of offspring and a shorter weaning period.
Coyotes mate for life, and a female will usually bear a litter of 2 – 12 pups in the spring
months. Cubs start eating solid food at about 3
weeks old and first hunt in groups led by the
mother coyote at age 6 to 10 weeks. Within six
months, the young coyotes are hunting alone
(www.natureparkcom).
Coyotes also have a shorter lifespan –
an average of six years – than giant pandas.
While they often hunt alone, coyotes will also travel in packs and work together to hunt
and kill a larger animal. The howling associated with the coyote is used as a form of
communication; coyotes howl or bark to warn of danger, to call pups, to celebrate or to
threaten others. Coyotes have a highly developed sense of smell as well as acute hearing.
These characteristics have enabled the coyotes to survive in both the wild and more
populated areas (www.desertusa.com).
Coyotes are extremely adaptable animals; they are generalists in the true sense of
the word. While the typical coyote diet consists of small mammals, insects, reptiles, fruit
and carrion, recent research suggests coyotes can exist on whatever the area offers in
terms of food. Coyotes are opportunistic predators, with a wide variety of hunting
techniques that they employ both day and night.
Coyotes, like pandas, are elusive and tend to avoid human interaction. They are
rarely seen, only heard. Coyotes have faced an additional threat that pandas have not;
there have been numerous efforts to control the coyote population, producing an animal
that is extremely alert and wary. As we have seen with pandas in captivity, animals that
are in constant contact with humans soon become less afraid. Coyotes go out of their
way to avoid humans, but as they become habituated to people, they will become bolder
approaching people. Coyotes have started to discover urbanized areas are a good source
of food; swimming pools, dog water dishes and ponds are convenient sources of water
(www.desertusa.com). Stanley Gerht of Ohio State University studied the coyote
population in greater Chicago over a six-year period. He found that urban coyotes tend to
live longer than rural counterparts, living anywhere from parks to industrial areas. “A
coyote living in urban Chicago has a 60-percent chance of surviving for a year, while a
rural coyote has a 30 % chance of living for another year” (www.world-science.net).
Gerht estimated there were up to 2,000 coyotes living in the greater Chicago area, and
hypothesized that other urban areas might be experiencing similar coyote populations.
The biological and behavioral differences of these two animals are the key to their
ability to survive when faced with a changing habitat. As a K-selected and specialist
species, pandas are neither resistant nor resilient to drastic changes in their habitat.
Natural selection has resulted in the evolution of pandas with characteristics that help
them to eat bamboo; if this major food source is eliminated, pandas cannot adapt quickly
enough to survive. Their low reproduction rate also hinders chances of survival in a
dwindling habitat. As the habitat fragmentation continues to isolate groups of pandas
from one another, the species faces a new problem: a diminishing gene pool. This could
lead to more genetic problems for the pandas. In contrast, coyotes are generalists who are
not tied to any specific food source. They have evolved with a set of characteristics that
allow them to adapt to a variety of habitats and diets. Coyotes have been able to thrive in
urban areas and have benefited from the decline of their main predator, the wolf.
This discussion begs the question, what role do humans have in protecting or
controlling these species? While there are natural causes of habitat fragmentation, the
habitat loss that has resulted in a diminishing panda population and an increased coyote
population is due primarily to human impact. Pandas have existed in the mountains of
East Asia for nearly three million years. Logging, agricultural expansion and human
population growth into the panda habitat has reduced the habitats to small, isolated
fragments. The pandas can no longer migrate to find new sources of bamboo if
necessary. Today, great amounts of money and resources are poured into protecting
pandas, especially those in captivity. Hosting a giant panda at a zoo cost an average of
2.6 million per year (Warren 48). The World Wildlife Fund has worked to protect
pandas in the wild, as well. China has banned logging in natural forests and started a 10-
billion dollar reforestation project. The government has also announced plan to invest a
billion dollars a year over 30 years to expand the protected areas (Warren 53). At the
same time, however, China is promising economic growth in the country’s poorest areas
and dedicating one hundred billion dollars toward this program. The program includes
construction, industry and tourism – and may overlap with the remaining panda habitat
(Warren 53).
Conversations also surround the issue of increasing coyote populations. There is
an ongoing disagreement about the value of coyote – some believe it is necessary to
preserve balance of nature. Those individuals with agricultural interests say the coyote
population should be controlled so it does not kill livestock or poultry. The position of
many biologists is a compromise; individual coyotes causing problems should be dealt
with, but the species as a whole is not harmful (“The Coyote”).
The issues and challenges surrounding habitat fragmentation are not going to go
away. As the human population continues to increase and we continue to expand our
own habitats, we inevitably affect the habitats of native species. The situations today
with pandas and coyotes are primarily a result of human activity. By studying these two
species, we can examine the extreme effects of our expansion. It is up to us to take
responsibility for our actions.
Works Cited
"Animal Info - Giant Panda." Animal Information. 12 Aug 2006
http://www.animalinfo.org/species/carnivor/ailumela.htm
"Giant Panda Still Threatened by Habitat Loss." EcoWorld . 12 Aug 2006
http://www.ecoworld.com/Home/articles2.cfm
Hill, Donna. "Coyote Information." NaturePark. 12 Aug 2006
www.naturepark.com/coyinfo.htm
"Pandas - Ecology." World Wildlife Fund. 2006. 11 Aug 2006
http://worldwildlife.org/pandas/ecology.htm
"The Coyote." Desert USA . 2006. 12 Aug 2006
www.desertusa.com/june96/du_cycot.html
Warren, Lynne. "Pandas, Inc." National Geographic July 2006: 42-59.
World Science Staff, "Thriving under our noses, stealthily: coyotes." World
Science. 05 Jan 2006. Ohio State University. 12 Aug 2006 http://www.worldscience.net