12-6-16Advanced Biology

Species Types and Interactions

1. Distinguish between the 4 main types of population interactions2. Distinguish between the 4 main types of special species

• Objective

AS ALWAYS DEAR STUDENTS…KEY CONCEPTS ARE UNDERLINEDVOCABULARY IN GREEN

• Niche – an organisms role in a community; what it eats, what eats it, what interactions it has with other populations

• Habitat – where an organism lives

Population interactions 1. Predator-prey: a relationship where one organism (the predator) eats the other (prey)• +/-

– Predator-prey interactions have resulted in unique adaptations• camouflage• warning colors• mimicry

2 rules about coloration

• Small + beautiful = poisonous• Beautiful + easy to catch = deadly

Aposematic coloration- poison arrow frog

Batesian mimicry Mullerian mimicry

2. Herbivory: +/- interaction; an herbivore eats a plant or algae – many plants possess adaptations that help them

avoid herbivory

Strychnos toxifera is a vine that produces strychnine

Population interactions

3. Competition – when two or more organisms need the same resource at the same time

• -/-

• Intraspecific competition – same species fight to win a resource

• Interspecific competition – different species, usually no fighting

Population Interactions

4. Symbiosis – when two or more different species live in close physical contact with each other

4a) Parasitism

• A form of symbiosis in which one organism benefits and the other is hurt

4b) Mutualism

• A form of symbiosis in which both organisms benefit

4c)Commensalism

• A form of symbiosis in which one organism benefits and the other is not harmed or helped

You tryWhat type(s) of population interaction(s) are at work here?

• Herds of zebra and flocks of ostriches often feed and move together across grasslands. Zebras can fight off predators more effectively that an ostrich and ostriches can stand taller and see farther across the plains.

You tryWhat type(s) of population interaction(s) are at work here?

• Honey badgers eat a wide variety of foods including honey from beehives when they can find one. Honeyguides eat honeybees and their larvae. When a honeyguide finds a hive it seeks out a badger and makes a loud call. As the badger rips into the hive, then bird eats the bees.

You tryWhat type(s) of population interaction(s) are at work here?

• False scorpions are very tiny and feed on small insects

• They have no means of travel except their very short legs, so sometimes they hitch rides on other animals, like this beetle

You tryWhat type(s) of population interaction(s) are at work here?

• Sooty shearwaters are seabirds that dig burrows in soft soil to lay their eggs. Both parents take turns caring for the egg. Sometimes, a tuatara will take over the burrow while the parents are out feeding. They may eat the egg or chick, and keep the parents from getting back in the burrow.

Special Species Types – species that affect the biodiversity of the ecosystem

1. Dominant species –the most abundant or highest biomass species in an ecosystem

2. Nonnative species

• Aka alien, invasive, exotic• Accidentally or deliberately introduced species

• Often the non-native species has no natural predators and takes over the ecosystem

3. Keystone species

• Have a large effect on the number and type of other species in the ecosystem

Examples:

• Top predators - feed on and help regulate the size of other populations

• Pollinators - control the size of plant populations

Effects of losing a keystone species

• When a keystone species is lost - it leads to population crashes and extinctions of other species

4. ecosystem engineers

• Aka foundation species• Play a major role in creating the

ecosystems in which they live

Examples:

• Elephants pull out or break small trees in the African savannah

• This allows grass to grow and benefits other grazers and open plains predators

Examples:

• Beavers - build dams to create ponds that other species benefit from

What species type(s) is this an example of?

• Sea stars are the main predator of mussels. When sea star populations decrease, mussel populations expand rapidly and take over most of the rock surfaces, crowding out other species like urchins, crabs, and limpets

What species type is this an example of?

• In the forests of Patagoinia, the Firecrown Hummingbird is the sole pollinator for nearly 20% of the local plant species

What species type is this an example of?

• Kudzu vine was brought from Asia to the United States in the late 1800s. It was uses as cattle fodder and as a way to control soil erosion. The plant grows very quickly (~1 foot/day) and is able to outcompete other plant species. It can kill trees by growing over and completely covering them. The USA spends $6 millions every year fighting kudzu with pesticides and removal

What species type is this an example of?

• The Indian Crested Porcupine digs for roots and tubers in the ground, creating large pits that remain for a long time. These pits fill with dead organic matter and make small patches of fertilizer that help more trees grow in the area

What species type is this an example of?

• Mangrove forests grow in tropical and subtropical area and are made up mostly of mangrove trees. The tree roots act as shelter for small organisms hiding from predators. Many aquatic animals have their babies or lay their eggs here so the young can be protected by hiding among the tree roots