Download Sarah Emmel Dr. Laura Altfeld BIO 220 April 23, 2010 Exam 3 Essay

Sarah Emmel
Dr. Laura Altfeld
BIO 220
April 23, 2010
Exam 3 Essay Questions
1.) The migration of the NE American Monarch Butterfly is a spectacular phenomenon. There is no
other type of animal movement in the world that can compare. Butterflies from southern
Canada and the northern states of America make a 2,000 mile journey to a special reserve set in
the Oyamel forests. The great trip begins in August and ends in November. Millions travel this
extreme distance to survive the winter. No one knows exactly how the butterfly does it, but
some of the theories include following landmarks and location of the stars or some form of
internal compass. Scientists have even taken a group of butterflies off course, but they found
their way to Mexico from a strange location.
During their journey, butterflies will rest at stop-over habitats. They do not stay long,
but long enough to forage for nectar to help them keep up their energy. There are many
dangers that face the butterflies on their journey including natural and industrial predators, but
he majority of the millions usually make the journey. The migration happens at the same time
every year, so people can actually track the butterflies as they travel. Once they reach Mexico
the butterflies nest in large groups and these clusters cling to the trees of the forests for
warmth. The trees retain heat and act as a radiator for the butterflies. This protects them from
the winter chill.
The butterflies are part of a huge culture tradition for the villagers of the small Mexican
towns. Mexicans believe that the butterfly carries with it the soul of their loved ones who have
passed on, so when the butterflies return they celebrate with a holiday called “Day of the
Dead.” The whole city comes together to decorate the graves of their deceased relatives to
make ready for their return. This holiday and migration actually helps to sustain the local
economy of the villages because it not only draws in tourists, but villagers by products from local
merchants to decorate and celebrate with.
Once February rolls around the butterflies become more active and start preparing for
the trip back. Many will travel north to Texas and there they will mate, the females will lay her
eggs, and then the parents die. Once the eggs hatch the caterpillars will eat and attempt to
survive through the transformation process. Once it becomes a butterfly it will continue north,
but this generation will never see northern America or Canada. It will mate, lay eggs, and then
die. The fourth generation will be born in Canada/Northern America and this generation will
make the great migration therefore completing the cycle and starting it all over again.
2.) The Optimal Diet Model of Foraging answers one main question; what to eat? Foraging is the
process of tracking, killing, and consuming food, so knowing what to eat is extremely important
to an animal species. The type of food is decided on based on genetic instincts, availability of
resources in a habitat, and learned behaviors (what was fed to the offspring will be what they
forage for and feed to their offspring).
It is important to remember that every prey item, whether it is live prey (rabbits,
gazelle, birds, etc.) or seeds, grass, leaves, etc. all have some form of value to the predator. The
value is usually measured in amount of calories. Also factored in is the prey’s encounter rate,
how often it is available to the predator, and the handling time. Handling time is the length of
time it takes for the predator to capture and ingest the prey. It is assumed that the greater the
amount of energy and handling time, the more profitable it will be to the predator and this
raises its chances to be selected as prey every time. Animals are very smart and will weigh the
encounter time with the handling time and the energy it takes to take care of all of these parts
of foraging.
3.) Protecting oneself from danger is very pertinent for the survival of genetic lineages and
preservation of a species, so the animal kingdom has developed many unique ways to protect
themselves from the predators that hunt them out. This skill can be mastered through three
crucial steps to predator protection. These steps are choose a safe habitat, blend into the
environment around you, and be quiet.
Choosing a safe environment is easier said than done because to choose a safe home is to pick
one that is completely predator free, which in this world is near impossible for prey animals. But
many animals have come up with ways to cope. Certain birds will nest in trees to protect their
offspring and burrowing squirrels sequence of tunnels have many entrances/exits to help them
make a quick escape if they need to.
Blending into one’s environment is a built in step to protecting oneself from a predator. Many
animals use a technique called cryptic coloration which allows them to located habitats with
plants/colors that match their skin/scale colorings. This prevents them from being an easy target
to passing predators. Camouflage is a well practiced tact by the animal world.
And finally, remaining silent is extremely important for prey who are hunted by predators that
rely on sound cues. Predators will actually eavesdrop on the sound being made by their prey to
hone in on where they are located. The prey are not aware of the fact that they are being
tracked by mating calls or stress signals, so knowing when to keep quiet is crucial to survival.
4.) Honesty is crucial in any type of relationship, but it is vital when it comes to communication
between animal populations. Without communication there would be mass chaos because they
would not know when to be stressed, whether or not food was available, and where they were
traveling to next. The idea of honesty is animal communication goes along with the thought that
the sender of the message may be trying to deceive the receiver. If this is the case, scientists
want to know why animals chose one over the other. Dishonesty in animal communication is
preventable, but it will only be stopped if the cost of being dishonest is something that ceases
the animals from having a normal life including limited resources like food and water.
5.) The Florida Scrub Jay is a very interesting bird. As it is with most birds, a male will defend a
territory. A territory is a section of land that may/may not have a resource of some kind and it is
where a group, small or large, may live, nest, feed, and reproduce. What makes it a territory is
that it is defended by one or more members of the group. The scrub jay has taken the idea of
territories to a new height. A monogamous pair, one male mating with a single female, will
establish a territory, build a nest, and reproduce there. In their territory they will have six
helpers who help defend the territory and raise the offspring. Once the male offspring reach a
sexually mature age they will go off and find space not occupied and that boarder their home
territory. This new section now belongs to the original scrub jay family and the offspring just
helped to “bud” the original space, but this new ground is all his. He will pick a mate and chose
helpers to assist him in the same way his parents were assisted. This cycle is passed down
through the generations and with each new male offspring the territory grows a bit more.
6.) The ways in which animals communicate with each other varies as much as it does among
human beings. Each species is different and there are many different “languages” to make
everyone unique. However there are three categories that generalize the different modes of
communication. The three categories are color, chemical, and auditory.
Color is a very simple way to communicate a message to other species. For example, a monarch
butterfly can be toxic to many animals who select it as prey. The bright orange coloring of the
wings with the black lines is a warning message that states “hey! I may be toxic to you, so you
do not want to eat me.” This type of communication tends to be very affective after a first
attempt, but it eventually gets the message across. Some other examples of color
communication are poisonous dart frogs (bright neon colors), different types of snakes, lizards,
and other insects (like bees and wasps).
Chemical communication can be a bit messy at times. The perfect example of chemical
communication is the potent smell emitted by skunks. Skunks only “spray” when they feel
threatened and the liquid they drench their opponents with is a way of distracting prey or, at
the very least, deters them from ever approaching a skunk ever again. Another example of this
type of communication can be found in insects like ants that use chemical communication to
signal other ants to a certain location for backup protection or good foraging opportunities.
And, finally, the last general category of communication is anything that is auditory. This covers
a wide range of the animal kingdom because most animals use some type of sound to express
feelings and send messages. Birds are the perfect example of auditory communicators. Different
species of birds will use different songs for everything. There will be one song for luring a mate,
announcing predator arrival, foraging, and one for every day singing. Sometimes birds can be
deceptive and sneaky and will use certain songs to lure other birds away from mates, for
example. This allows them to make a move in to pass on their genetic traits. Other examples of
auditory communication can be found throughout the animal kingdom including mammals (both
on land and under the ocean), lizards, insects, and reptiles.
So, in conclusion, communication is vital for the survival of not only specific populations, but it is
truly vital for the survival of entire species. Though many groups may use just color as a form of
communication, the message is easily interpreted by not only those in the population, but also
of those outside the species. Chemical communication tends to be a bite more specific and
subtle, not really picked up by outside members, but it is a great way to pass along a message
without risking interference. And finally auditory communication is the most apparent form of
communication and is very common in the animal kingdom. Though humans may not be able to
exactly decipher what messages are being shared, it is easy to guess based on the tone of the
sound and other energy being exerted during the communication. However this allows outsiders
to learn what certain sounds mean and can be quite risky, but the risk is worth it when it comes
to maintaining an entire population.
Work Referenced
Dugatkin, Lee. Principles of Animal Behavior. 2nd. New York, NY:
W.W. Norton & Company, 2009. ch. 10-13. Print.