SAVANNA
1. Lions are distributed in clumps because this makes it easier to hunt in packs and capture more
prey for the pride. Elephants are also distributed in clumps for protection. Herds are made up of
females related by blood and their young. This is called kin speciation, as altruistic behavior is
expressed in order to enhance the reproductive success of relatives. Trees such as the acacias tree
tend to be distributed randomly because of the extensive savanna fires.
2. The density independent factors are limiting factors that cannot be controlled by the animals
within the biome. Density independent factors of the Savanna include risk of fires, a lack of
water due to drought, poaching, development, and any other natural disasters.
3. Elephants are K-selected species, as they produce very few offspring. Over their lifetime, a
pair of elephants typically produces six offspring. This increases the chance of survival of the
offspring because the female and her herd are able to protect the babies better when there are
fewer. Elephants also tend to be larger in size and have a long life expectancy, traits common in
K-selection. Most insects that live on the savanna are R-selected species. This is because these
species have a relatively short life, reach reproductive maturity at a young age, have a low
biomass, and have the potential to produce large numbers of small offspring at a time. Insects
tend to reproduce rapidly to increase the survival rate of their offspring. Rhinoceroses exhibit Kselection also. Rhinos tend to live in small groups called crashes and only produce one offspring
at a time. Parent rhinos are extremely protective of their babies.
4. Commensalism is a relationship between two organisms where one is benefited and the other
is not affected. Mutualism is a relationship between two organisms where both are benefitted.
Parasitism is a relationship between two organisms where one is benefited and the other is
harmed. An example of commensalism is between most large grazers and the egret. The egret
feasts on insects that are aroused into flight because of the grazing of the animals. The egret
benefits from the food provided by the grazers, while the grazers are neither helped nor harmed.
An example of parasitism is between a tick and an elephant. The tick sucks the blood of the
elephant, which ultimately harms the elephant and benefits the tick. An example of mutualism is
between the African ant and the acacia trees. The ants protect the trees from leaf eating insects,
while still allowing for pollinating bees and insects, allowing for reproduction. The tree provides
a safe home for the ant, while the ant protects the tree.
5. Batesian mimicry is when a harmless species mimics a harmful species to avoid predation.
--in few savannas, the monarch butterfly is abundant, yet very poisonous to predators.
Another species of butterfly, the viceroy, is not poisonous and is therefore preyed on more often.
In an attempt to protect itself, the viceroy mimics the colors of the monarch in order to deceive
predators.
Viceroy
monarch
Cryptic coloration is camouflage which makes prey difficult to spot.
-After times of fire on the savanna, many animals are exposed by the juxtaposition of
their bright coloring against the charred ground. However, organisms such as the grass hopper
have the ability to change their coloring to an ashy coloring than matches the ground, providing
camouflage.
Deceptive markings are markings that are used to warn predators that the organism
unpalatable or noxious and these markings are also used to lure possible prey. This can also be
known as aposematism, where markings and coloration is used to ward off predators.
-It was very difficult to find an example of deceptive markings, but here is a video on
aposematic coloration!
http://www.youtube.com/watch?v=lXi1fQ50Bc8
Mullerian mimicry is when two or more different species resemble each other. Each species
gains an advantage because there is an increased number in the possible prey
-Leopards and cheetahs exhibit similar coloration and spots, which would confuse prey.
The coloration of a cheetah would warn the prey of the impending attack, and this therefore
would also prevent leopards from attacking prey. This would be a negative effect.